vk_mem_alloc.h

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//
// Copyright (c) 2017-2019 Advanced Micro Devices, Inc. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#ifndef AMD_VULKAN_MEMORY_ALLOCATOR_H
#define AMD_VULKAN_MEMORY_ALLOCATOR_H

#ifdef __cplusplus
extern "C" {
#endif

/*
Define this macro to 0/1 to disable/enable support for recording functionality,
available through VmaAllocatorCreateInfo::pRecordSettings.
*/
#ifndef VMA_RECORDING_ENABLED
    #ifdef _WIN32
        #define VMA_RECORDING_ENABLED 1
    #else
        #define VMA_RECORDING_ENABLED 0
    #endif
#endif

#ifndef NOMINMAX
    #define NOMINMAX // For windows.h
#endif

#ifndef VULKAN_H_
    #include <vulkan/vulkan.h>
#endif

#if VMA_RECORDING_ENABLED
    #include <windows.h>
#endif

#if !defined(VMA_DEDICATED_ALLOCATION)
    #if VK_KHR_get_memory_requirements2 && VK_KHR_dedicated_allocation
        #define VMA_DEDICATED_ALLOCATION 1
    #else
        #define VMA_DEDICATED_ALLOCATION 0
    #endif
#endif

VK_DEFINE_HANDLE(VmaAllocator)

typedef void (VKAPI_PTR *PFN_vmaAllocateDeviceMemoryFunction)(
    VmaAllocator      allocator,
    uint32_t          memoryType,
    VkDeviceMemory    memory,
    VkDeviceSize      size);
typedef void (VKAPI_PTR *PFN_vmaFreeDeviceMemoryFunction)(
    VmaAllocator      allocator,
    uint32_t          memoryType,
    VkDeviceMemory    memory,
    VkDeviceSize      size);

typedef struct VmaDeviceMemoryCallbacks {
    PFN_vmaAllocateDeviceMemoryFunction pfnAllocate;
    PFN_vmaFreeDeviceMemoryFunction pfnFree;
} VmaDeviceMemoryCallbacks;

typedef enum VmaAllocatorCreateFlagBits {
    VMA_ALLOCATOR_CREATE_EXTERNALLY_SYNCHRONIZED_BIT = 0x00000001,
    VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT = 0x00000002,

    VMA_ALLOCATOR_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
} VmaAllocatorCreateFlagBits;
typedef VkFlags VmaAllocatorCreateFlags;

typedef struct VmaVulkanFunctions {
    PFN_vkGetPhysicalDeviceProperties vkGetPhysicalDeviceProperties;
    PFN_vkGetPhysicalDeviceMemoryProperties vkGetPhysicalDeviceMemoryProperties;
    PFN_vkAllocateMemory vkAllocateMemory;
    PFN_vkFreeMemory vkFreeMemory;
    PFN_vkMapMemory vkMapMemory;
    PFN_vkUnmapMemory vkUnmapMemory;
    PFN_vkFlushMappedMemoryRanges vkFlushMappedMemoryRanges;
    PFN_vkInvalidateMappedMemoryRanges vkInvalidateMappedMemoryRanges;
    PFN_vkBindBufferMemory vkBindBufferMemory;
    PFN_vkBindImageMemory vkBindImageMemory;
    PFN_vkGetBufferMemoryRequirements vkGetBufferMemoryRequirements;
    PFN_vkGetImageMemoryRequirements vkGetImageMemoryRequirements;
    PFN_vkCreateBuffer vkCreateBuffer;
    PFN_vkDestroyBuffer vkDestroyBuffer;
    PFN_vkCreateImage vkCreateImage;
    PFN_vkDestroyImage vkDestroyImage;
    PFN_vkCmdCopyBuffer vkCmdCopyBuffer;
#if VMA_DEDICATED_ALLOCATION
    PFN_vkGetBufferMemoryRequirements2KHR vkGetBufferMemoryRequirements2KHR;
    PFN_vkGetImageMemoryRequirements2KHR vkGetImageMemoryRequirements2KHR;
#endif
} VmaVulkanFunctions;

typedef enum VmaRecordFlagBits {
    VMA_RECORD_FLUSH_AFTER_CALL_BIT = 0x00000001,
    
    VMA_RECORD_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
} VmaRecordFlagBits;
typedef VkFlags VmaRecordFlags;

typedef struct VmaRecordSettings
{
    VmaRecordFlags flags;
    const char* pFilePath;
} VmaRecordSettings;

typedef struct VmaAllocatorCreateInfo
{
    VmaAllocatorCreateFlags flags;

    VkPhysicalDevice physicalDevice;

    VkDevice device;

    VkDeviceSize preferredLargeHeapBlockSize;

    const VkAllocationCallbacks* pAllocationCallbacks;

    const VmaDeviceMemoryCallbacks* pDeviceMemoryCallbacks;
    uint32_t frameInUseCount;
    const VkDeviceSize* pHeapSizeLimit;
    const VmaVulkanFunctions* pVulkanFunctions;
    const VmaRecordSettings* pRecordSettings;
} VmaAllocatorCreateInfo;

VkResult vmaCreateAllocator(
    const VmaAllocatorCreateInfo* pCreateInfo,
    VmaAllocator* pAllocator);

void vmaDestroyAllocator(
    VmaAllocator allocator);

void vmaGetPhysicalDeviceProperties(
    VmaAllocator allocator,
    const VkPhysicalDeviceProperties** ppPhysicalDeviceProperties);

void vmaGetMemoryProperties(
    VmaAllocator allocator,
    const VkPhysicalDeviceMemoryProperties** ppPhysicalDeviceMemoryProperties);

void vmaGetMemoryTypeProperties(
    VmaAllocator allocator,
    uint32_t memoryTypeIndex,
    VkMemoryPropertyFlags* pFlags);

void vmaSetCurrentFrameIndex(
    VmaAllocator allocator,
    uint32_t frameIndex);

typedef struct VmaStatInfo
{
    uint32_t blockCount;
    uint32_t allocationCount;
    uint32_t unusedRangeCount;
    VkDeviceSize usedBytes;
    VkDeviceSize unusedBytes;
    VkDeviceSize allocationSizeMin, allocationSizeAvg, allocationSizeMax;
    VkDeviceSize unusedRangeSizeMin, unusedRangeSizeAvg, unusedRangeSizeMax;
} VmaStatInfo;

typedef struct VmaStats
{
    VmaStatInfo memoryType[VK_MAX_MEMORY_TYPES];
    VmaStatInfo memoryHeap[VK_MAX_MEMORY_HEAPS];
    VmaStatInfo total;
} VmaStats;

void vmaCalculateStats(
    VmaAllocator allocator,
    VmaStats* pStats);

#ifndef VMA_STATS_STRING_ENABLED
#define VMA_STATS_STRING_ENABLED 1
#endif

#if VMA_STATS_STRING_ENABLED


void vmaBuildStatsString(
    VmaAllocator allocator,
    char** ppStatsString,
    VkBool32 detailedMap);

void vmaFreeStatsString(
    VmaAllocator allocator,
    char* pStatsString);

#endif // #if VMA_STATS_STRING_ENABLED

VK_DEFINE_HANDLE(VmaPool)

typedef enum VmaMemoryUsage
{
    VMA_MEMORY_USAGE_UNKNOWN = 0,
    VMA_MEMORY_USAGE_GPU_ONLY = 1,
    VMA_MEMORY_USAGE_CPU_ONLY = 2,
    VMA_MEMORY_USAGE_CPU_TO_GPU = 3,
    VMA_MEMORY_USAGE_GPU_TO_CPU = 4,
    VMA_MEMORY_USAGE_MAX_ENUM = 0x7FFFFFFF
} VmaMemoryUsage;

typedef enum VmaAllocationCreateFlagBits {
    VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT = 0x00000001,

    VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT = 0x00000002,
    VMA_ALLOCATION_CREATE_MAPPED_BIT = 0x00000004,
    VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT = 0x00000008,
    VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT = 0x00000010,
    VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT = 0x00000020,
    VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT = 0x00000040,
    VMA_ALLOCATION_CREATE_DONT_BIND_BIT = 0x00000080,

    VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT  = 0x00010000,
    VMA_ALLOCATION_CREATE_STRATEGY_WORST_FIT_BIT = 0x00020000,
    VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT = 0x00040000,

    VMA_ALLOCATION_CREATE_STRATEGY_MIN_MEMORY_BIT = VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT,
    VMA_ALLOCATION_CREATE_STRATEGY_MIN_TIME_BIT = VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT,
    VMA_ALLOCATION_CREATE_STRATEGY_MIN_FRAGMENTATION_BIT = VMA_ALLOCATION_CREATE_STRATEGY_WORST_FIT_BIT,

    VMA_ALLOCATION_CREATE_STRATEGY_MASK =
        VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT |
        VMA_ALLOCATION_CREATE_STRATEGY_WORST_FIT_BIT |
        VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT,

    VMA_ALLOCATION_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
} VmaAllocationCreateFlagBits;
typedef VkFlags VmaAllocationCreateFlags;

typedef struct VmaAllocationCreateInfo
{
    VmaAllocationCreateFlags flags;
    VmaMemoryUsage usage;
    VkMemoryPropertyFlags requiredFlags;
    VkMemoryPropertyFlags preferredFlags;
    uint32_t memoryTypeBits;
    VmaPool pool;
    void* pUserData;
} VmaAllocationCreateInfo;

VkResult vmaFindMemoryTypeIndex(
    VmaAllocator allocator,
    uint32_t memoryTypeBits,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex);

VkResult vmaFindMemoryTypeIndexForBufferInfo(
    VmaAllocator allocator,
    const VkBufferCreateInfo* pBufferCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex);

VkResult vmaFindMemoryTypeIndexForImageInfo(
    VmaAllocator allocator,
    const VkImageCreateInfo* pImageCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex);

typedef enum VmaPoolCreateFlagBits {
    VMA_POOL_CREATE_IGNORE_BUFFER_IMAGE_GRANULARITY_BIT = 0x00000002,

    VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT = 0x00000004,

    VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT = 0x00000008,

    VMA_POOL_CREATE_ALGORITHM_MASK =
        VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT |
        VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT,

    VMA_POOL_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
} VmaPoolCreateFlagBits;
typedef VkFlags VmaPoolCreateFlags;

typedef struct VmaPoolCreateInfo {
    uint32_t memoryTypeIndex;
    VmaPoolCreateFlags flags;
    VkDeviceSize blockSize;
    size_t minBlockCount;
    size_t maxBlockCount;
    uint32_t frameInUseCount;
} VmaPoolCreateInfo;

typedef struct VmaPoolStats {
    VkDeviceSize size;
    VkDeviceSize unusedSize;
    size_t allocationCount;
    size_t unusedRangeCount;
    VkDeviceSize unusedRangeSizeMax;
    size_t blockCount;
} VmaPoolStats;

VkResult vmaCreatePool(
    VmaAllocator allocator,
    const VmaPoolCreateInfo* pCreateInfo,
    VmaPool* pPool);

void vmaDestroyPool(
    VmaAllocator allocator,
    VmaPool pool);

void vmaGetPoolStats(
    VmaAllocator allocator,
    VmaPool pool,
    VmaPoolStats* pPoolStats);

void vmaMakePoolAllocationsLost(
    VmaAllocator allocator,
    VmaPool pool,
    size_t* pLostAllocationCount);

VkResult vmaCheckPoolCorruption(VmaAllocator allocator, VmaPool pool);

VK_DEFINE_HANDLE(VmaAllocation)


typedef struct VmaAllocationInfo {
    uint32_t memoryType;
    VkDeviceMemory deviceMemory;
    VkDeviceSize offset;
    VkDeviceSize size;
    void* pMappedData;
    void* pUserData;
} VmaAllocationInfo;

VkResult vmaAllocateMemory(
    VmaAllocator allocator,
    const VkMemoryRequirements* pVkMemoryRequirements,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo);

VkResult vmaAllocateMemoryPages(
    VmaAllocator allocator,
    const VkMemoryRequirements* pVkMemoryRequirements,
    const VmaAllocationCreateInfo* pCreateInfo,
    size_t allocationCount,
    VmaAllocation* pAllocations,
    VmaAllocationInfo* pAllocationInfo);

VkResult vmaAllocateMemoryForBuffer(
    VmaAllocator allocator,
    VkBuffer buffer,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo);

VkResult vmaAllocateMemoryForImage(
    VmaAllocator allocator,
    VkImage image,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo);

void vmaFreeMemory(
    VmaAllocator allocator,
    VmaAllocation allocation);

void vmaFreeMemoryPages(
    VmaAllocator allocator,
    size_t allocationCount,
    VmaAllocation* pAllocations);

VkResult vmaResizeAllocation(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkDeviceSize newSize);

void vmaGetAllocationInfo(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VmaAllocationInfo* pAllocationInfo);

VkBool32 vmaTouchAllocation(
    VmaAllocator allocator,
    VmaAllocation allocation);

void vmaSetAllocationUserData(
    VmaAllocator allocator,
    VmaAllocation allocation,
    void* pUserData);

void vmaCreateLostAllocation(
    VmaAllocator allocator,
    VmaAllocation* pAllocation);

VkResult vmaMapMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    void** ppData);

void vmaUnmapMemory(
    VmaAllocator allocator,
    VmaAllocation allocation);

void vmaFlushAllocation(VmaAllocator allocator, VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size);

void vmaInvalidateAllocation(VmaAllocator allocator, VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size);

VkResult vmaCheckCorruption(VmaAllocator allocator, uint32_t memoryTypeBits);

VK_DEFINE_HANDLE(VmaDefragmentationContext)

typedef enum VmaDefragmentationFlagBits {
    VMA_DEFRAGMENTATION_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
} VmaDefragmentationFlagBits;
typedef VkFlags VmaDefragmentationFlags;

typedef struct VmaDefragmentationInfo2 {
    VmaDefragmentationFlags flags;
    uint32_t allocationCount;
    VmaAllocation* pAllocations;
    VkBool32* pAllocationsChanged;
    uint32_t poolCount;
    VmaPool* pPools;
    VkDeviceSize maxCpuBytesToMove;
    uint32_t maxCpuAllocationsToMove;
    VkDeviceSize maxGpuBytesToMove;
    uint32_t maxGpuAllocationsToMove;
    VkCommandBuffer commandBuffer;
} VmaDefragmentationInfo2;

typedef struct VmaDefragmentationInfo {
    VkDeviceSize maxBytesToMove;
    uint32_t maxAllocationsToMove;
} VmaDefragmentationInfo;

typedef struct VmaDefragmentationStats {
    VkDeviceSize bytesMoved;
    VkDeviceSize bytesFreed;
    uint32_t allocationsMoved;
    uint32_t deviceMemoryBlocksFreed;
} VmaDefragmentationStats;

VkResult vmaDefragmentationBegin(
    VmaAllocator allocator,
    const VmaDefragmentationInfo2* pInfo,
    VmaDefragmentationStats* pStats,
    VmaDefragmentationContext *pContext);

VkResult vmaDefragmentationEnd(
    VmaAllocator allocator,
    VmaDefragmentationContext context);

VkResult vmaDefragment(
    VmaAllocator allocator,
    VmaAllocation* pAllocations,
    size_t allocationCount,
    VkBool32* pAllocationsChanged,
    const VmaDefragmentationInfo *pDefragmentationInfo,
    VmaDefragmentationStats* pDefragmentationStats);

VkResult vmaBindBufferMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkBuffer buffer);

VkResult vmaBindImageMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkImage image);

VkResult vmaCreateBuffer(
    VmaAllocator allocator,
    const VkBufferCreateInfo* pBufferCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VkBuffer* pBuffer,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo);

void vmaDestroyBuffer(
    VmaAllocator allocator,
    VkBuffer buffer,
    VmaAllocation allocation);

VkResult vmaCreateImage(
    VmaAllocator allocator,
    const VkImageCreateInfo* pImageCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VkImage* pImage,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo);

void vmaDestroyImage(
    VmaAllocator allocator,
    VkImage image,
    VmaAllocation allocation);

#ifdef __cplusplus
}
#endif

#endif // AMD_VULKAN_MEMORY_ALLOCATOR_H

// For Visual Studio IntelliSense.
#if defined(__cplusplus) && defined(__INTELLISENSE__)
#define VMA_IMPLEMENTATION
#endif

#ifdef VMA_IMPLEMENTATION
#undef VMA_IMPLEMENTATION

#include <cstdint>
#include <cstdlib>
#include <cstring>

/*******************************************************************************
CONFIGURATION SECTION

Define some of these macros before each #include of this header or change them
here if you need other then default behavior depending on your environment.
*/

/*
Define this macro to 1 to make the library fetch pointers to Vulkan functions
internally, like:

    vulkanFunctions.vkAllocateMemory = &vkAllocateMemory;

Define to 0 if you are going to provide you own pointers to Vulkan functions via
VmaAllocatorCreateInfo::pVulkanFunctions.
*/
#if !defined(VMA_STATIC_VULKAN_FUNCTIONS) && !defined(VK_NO_PROTOTYPES)
#define VMA_STATIC_VULKAN_FUNCTIONS 1
#endif

// Define this macro to 1 to make the library use STL containers instead of its own implementation.
//#define VMA_USE_STL_CONTAINERS 1

/* Set this macro to 1 to make the library including and using STL containers:
std::pair, std::vector, std::list, std::unordered_map.

Set it to 0 or undefined to make the library using its own implementation of
the containers.
*/
#if VMA_USE_STL_CONTAINERS
   #define VMA_USE_STL_VECTOR 1
   #define VMA_USE_STL_UNORDERED_MAP 1
   #define VMA_USE_STL_LIST 1
#endif

#ifndef VMA_USE_STL_SHARED_MUTEX
    // Compiler conforms to C++17.
    #if __cplusplus >= 201703L
        #define VMA_USE_STL_SHARED_MUTEX 1
    // Visual studio defines __cplusplus properly only when passed additional parameter: /Zc:__cplusplus
    // Otherwise it's always 199711L, despite shared_mutex works since Visual Studio 2015 Update 2.
    // See: https://blogs.msdn.microsoft.com/vcblog/2018/04/09/msvc-now-correctly-reports-__cplusplus/
    #elif defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 190023918 && __cplusplus == 199711L && _MSVC_LANG >= 201703L
        #define VMA_USE_STL_SHARED_MUTEX 1
    #else
        #define VMA_USE_STL_SHARED_MUTEX 0
    #endif
#endif

/*
THESE INCLUDES ARE NOT ENABLED BY DEFAULT.
Library has its own container implementation.
*/
#if VMA_USE_STL_VECTOR
   #include <vector>
#endif

#if VMA_USE_STL_UNORDERED_MAP
   #include <unordered_map>
#endif

#if VMA_USE_STL_LIST
   #include <list>
#endif

/*
Following headers are used in this CONFIGURATION section only, so feel free to
remove them if not needed.
*/
#include <cassert> // for assert
#include <algorithm> // for min, max
#include <mutex>

#ifndef VMA_NULL
   // Value used as null pointer. Define it to e.g.: nullptr, NULL, 0, (void*)0.
   #define VMA_NULL   nullptr
#endif

#if defined(__ANDROID_API__) && (__ANDROID_API__ < 16)
#include <cstdlib>
void *aligned_alloc(size_t alignment, size_t size)
{
    // alignment must be >= sizeof(void*)
    if(alignment < sizeof(void*))
    {
        alignment = sizeof(void*);
    }

    return memalign(alignment, size);
}
#elif defined(__APPLE__) || defined(__ANDROID__)
#include <cstdlib>
void *aligned_alloc(size_t alignment, size_t size)
{
    // alignment must be >= sizeof(void*)
    if(alignment < sizeof(void*))
    {
        alignment = sizeof(void*);
    }

    void *pointer;
    if(posix_memalign(&pointer, alignment, size) == 0)
        return pointer;
    return VMA_NULL;
}
#endif

// If your compiler is not compatible with C++11 and definition of
// aligned_alloc() function is missing, uncommeting following line may help:

//#include <malloc.h>

// Normal assert to check for programmer's errors, especially in Debug configuration.
#ifndef VMA_ASSERT
   #ifdef _DEBUG
       #define VMA_ASSERT(expr)         assert(expr)
   #else
       #define VMA_ASSERT(expr)
   #endif
#endif

// Assert that will be called very often, like inside data structures e.g. operator[].
// Making it non-empty can make program slow.
#ifndef VMA_HEAVY_ASSERT
   #ifdef _DEBUG
       #define VMA_HEAVY_ASSERT(expr)   //VMA_ASSERT(expr)
   #else
       #define VMA_HEAVY_ASSERT(expr)
   #endif
#endif

#ifndef VMA_ALIGN_OF
   #define VMA_ALIGN_OF(type)       (__alignof(type))
#endif

#ifndef VMA_SYSTEM_ALIGNED_MALLOC
   #if defined(_WIN32)
       #define VMA_SYSTEM_ALIGNED_MALLOC(size, alignment)   (_aligned_malloc((size), (alignment)))
   #else
       #define VMA_SYSTEM_ALIGNED_MALLOC(size, alignment)   (aligned_alloc((alignment), (size) ))
   #endif
#endif

#ifndef VMA_SYSTEM_FREE
   #if defined(_WIN32)
       #define VMA_SYSTEM_FREE(ptr)   _aligned_free(ptr)
   #else
       #define VMA_SYSTEM_FREE(ptr)   free(ptr)
   #endif
#endif

#ifndef VMA_MIN
   #define VMA_MIN(v1, v2)    (std::min((v1), (v2)))
#endif

#ifndef VMA_MAX
   #define VMA_MAX(v1, v2)    (std::max((v1), (v2)))
#endif

#ifndef VMA_SWAP
   #define VMA_SWAP(v1, v2)   std::swap((v1), (v2))
#endif

#ifndef VMA_SORT
   #define VMA_SORT(beg, end, cmp)  std::sort(beg, end, cmp)
#endif

#ifndef VMA_DEBUG_LOG
   #define VMA_DEBUG_LOG(format, ...)
   /*
   #define VMA_DEBUG_LOG(format, ...) do { \
       printf(format, __VA_ARGS__); \
       printf("\n"); \
   } while(false)
   */
#endif

// Define this macro to 1 to enable functions: vmaBuildStatsString, vmaFreeStatsString.
#if VMA_STATS_STRING_ENABLED
    static inline void VmaUint32ToStr(char* outStr, size_t strLen, uint32_t num)
    {
        snprintf(outStr, strLen, "%u", static_cast<unsigned int>(num));
    }
    static inline void VmaUint64ToStr(char* outStr, size_t strLen, uint64_t num)
    {
        snprintf(outStr, strLen, "%llu", static_cast<unsigned long long>(num));
    }
    static inline void VmaPtrToStr(char* outStr, size_t strLen, const void* ptr)
    {
        snprintf(outStr, strLen, "%p", ptr);
    }
#endif

#ifndef VMA_MUTEX
    class VmaMutex
    {
    public:
        void Lock() { m_Mutex.lock(); }
        void Unlock() { m_Mutex.unlock(); }
    private:
        std::mutex m_Mutex;
    };
    #define VMA_MUTEX VmaMutex
#endif

// Read-write mutex, where "read" is shared access, "write" is exclusive access.
#ifndef VMA_RW_MUTEX
    #if VMA_USE_STL_SHARED_MUTEX
        // Use std::shared_mutex from C++17.
        #include <shared_mutex>
        class VmaRWMutex
        {
        public:
            void LockRead() { m_Mutex.lock_shared(); }
            void UnlockRead() { m_Mutex.unlock_shared(); }
            void LockWrite() { m_Mutex.lock(); }
            void UnlockWrite() { m_Mutex.unlock(); }
        private:
            std::shared_mutex m_Mutex;
        };
        #define VMA_RW_MUTEX VmaRWMutex
    #elif defined(_WIN32) && defined(WINVER) && WINVER >= 0x0600
        // Use SRWLOCK from WinAPI.
        // Minimum supported client = Windows Vista, server = Windows Server 2008.
        class VmaRWMutex
        {
        public:
            VmaRWMutex() { InitializeSRWLock(&m_Lock); }
            void LockRead() { AcquireSRWLockShared(&m_Lock); }
            void UnlockRead() { ReleaseSRWLockShared(&m_Lock); }
            void LockWrite() { AcquireSRWLockExclusive(&m_Lock); }
            void UnlockWrite() { ReleaseSRWLockExclusive(&m_Lock); }
        private:
            SRWLOCK m_Lock;
        };
        #define VMA_RW_MUTEX VmaRWMutex
    #else
        // Less efficient fallback: Use normal mutex.
        class VmaRWMutex
        {
        public:
            void LockRead() { m_Mutex.Lock(); }
            void UnlockRead() { m_Mutex.Unlock(); }
            void LockWrite() { m_Mutex.Lock(); }
            void UnlockWrite() { m_Mutex.Unlock(); }
        private:
            VMA_MUTEX m_Mutex;
        };
        #define VMA_RW_MUTEX VmaRWMutex
    #endif // #if VMA_USE_STL_SHARED_MUTEX
#endif // #ifndef VMA_RW_MUTEX

/*
If providing your own implementation, you need to implement a subset of std::atomic:

- Constructor(uint32_t desired)
- uint32_t load() const
- void store(uint32_t desired)
- bool compare_exchange_weak(uint32_t& expected, uint32_t desired)
*/
#ifndef VMA_ATOMIC_UINT32
    #include <atomic>
    #define VMA_ATOMIC_UINT32 std::atomic<uint32_t>
#endif

#ifndef VMA_DEBUG_ALWAYS_DEDICATED_MEMORY

    #define VMA_DEBUG_ALWAYS_DEDICATED_MEMORY (0)
#endif

#ifndef VMA_DEBUG_ALIGNMENT

    #define VMA_DEBUG_ALIGNMENT (1)
#endif

#ifndef VMA_DEBUG_MARGIN

    #define VMA_DEBUG_MARGIN (0)
#endif

#ifndef VMA_DEBUG_INITIALIZE_ALLOCATIONS

    #define VMA_DEBUG_INITIALIZE_ALLOCATIONS (0)
#endif

#ifndef VMA_DEBUG_DETECT_CORRUPTION

    #define VMA_DEBUG_DETECT_CORRUPTION (0)
#endif

#ifndef VMA_DEBUG_GLOBAL_MUTEX

    #define VMA_DEBUG_GLOBAL_MUTEX (0)
#endif

#ifndef VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY

    #define VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY (1)
#endif

#ifndef VMA_SMALL_HEAP_MAX_SIZE
   #define VMA_SMALL_HEAP_MAX_SIZE (1024ull * 1024 * 1024)
#endif

#ifndef VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE
   #define VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE (256ull * 1024 * 1024)
#endif

#ifndef VMA_CLASS_NO_COPY
    #define VMA_CLASS_NO_COPY(className) \
        private: \
            className(const className&) = delete; \
            className& operator=(const className&) = delete;
#endif

static const uint32_t VMA_FRAME_INDEX_LOST = UINT32_MAX;

// Decimal 2139416166, float NaN, little-endian binary 66 E6 84 7F.
static const uint32_t VMA_CORRUPTION_DETECTION_MAGIC_VALUE = 0x7F84E666;

static const uint8_t VMA_ALLOCATION_FILL_PATTERN_CREATED   = 0xDC;
static const uint8_t VMA_ALLOCATION_FILL_PATTERN_DESTROYED = 0xEF;

/*******************************************************************************
END OF CONFIGURATION
*/

static const uint32_t VMA_ALLOCATION_INTERNAL_STRATEGY_MIN_OFFSET = 0x10000000u;

static VkAllocationCallbacks VmaEmptyAllocationCallbacks = {
    VMA_NULL, VMA_NULL, VMA_NULL, VMA_NULL, VMA_NULL, VMA_NULL };

// Returns number of bits set to 1 in (v).
static inline uint32_t VmaCountBitsSet(uint32_t v)
{
    uint32_t c = v - ((v >> 1) & 0x55555555);
    c = ((c >>  2) & 0x33333333) + (c & 0x33333333);
    c = ((c >>  4) + c) & 0x0F0F0F0F;
    c = ((c >>  8) + c) & 0x00FF00FF;
    c = ((c >> 16) + c) & 0x0000FFFF;
    return c;
}

// Aligns given value up to nearest multiply of align value. For example: VmaAlignUp(11, 8) = 16.
// Use types like uint32_t, uint64_t as T.
template <typename T>
static inline T VmaAlignUp(T val, T align)
{
    return (val + align - 1) / align * align;
}
// Aligns given value down to nearest multiply of align value. For example: VmaAlignUp(11, 8) = 8.
// Use types like uint32_t, uint64_t as T.
template <typename T>
static inline T VmaAlignDown(T val, T align)
{
    return val / align * align;
}

// Division with mathematical rounding to nearest number.
template <typename T>
static inline T VmaRoundDiv(T x, T y)
{
    return (x + (y / (T)2)) / y;
}

/*
Returns true if given number is a power of two.
T must be unsigned integer number or signed integer but always nonnegative.
For 0 returns true.
*/
template <typename T>
inline bool VmaIsPow2(T x)
{
    return (x & (x-1)) == 0;
}

// Returns smallest power of 2 greater or equal to v.
static inline uint32_t VmaNextPow2(uint32_t v)
{
    v--;
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    v++;
    return v;
}
static inline uint64_t VmaNextPow2(uint64_t v)
{
    v--;
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    v |= v >> 32;
    v++;
    return v;
}

// Returns largest power of 2 less or equal to v.
static inline uint32_t VmaPrevPow2(uint32_t v)
{
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    v = v ^ (v >> 1);
    return v;
}
static inline uint64_t VmaPrevPow2(uint64_t v)
{
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    v |= v >> 32;
    v = v ^ (v >> 1);
    return v;
}

static inline bool VmaStrIsEmpty(const char* pStr)
{
    return pStr == VMA_NULL || *pStr == '\0';
}

#if VMA_STATS_STRING_ENABLED

static const char* VmaAlgorithmToStr(uint32_t algorithm)
{
    switch(algorithm)
    {
    case VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT:
        return "Linear";
    case VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT:
        return "Buddy";
    case 0:
        return "Default";
    default:
        VMA_ASSERT(0);
        return "";
    }
}

#endif // #if VMA_STATS_STRING_ENABLED

#ifndef VMA_SORT

template<typename Iterator, typename Compare>
Iterator VmaQuickSortPartition(Iterator beg, Iterator end, Compare cmp)
{
    Iterator centerValue = end; --centerValue;
    Iterator insertIndex = beg;
    for(Iterator memTypeIndex = beg; memTypeIndex < centerValue; ++memTypeIndex)
    {
        if(cmp(*memTypeIndex, *centerValue))
        {
            if(insertIndex != memTypeIndex)
            {
                VMA_SWAP(*memTypeIndex, *insertIndex);
            }
            ++insertIndex;
        }
    }
    if(insertIndex != centerValue)
    {
        VMA_SWAP(*insertIndex, *centerValue);
    }
    return insertIndex;
}

template<typename Iterator, typename Compare>
void VmaQuickSort(Iterator beg, Iterator end, Compare cmp)
{
    if(beg < end)
    {
        Iterator it = VmaQuickSortPartition<Iterator, Compare>(beg, end, cmp);
        VmaQuickSort<Iterator, Compare>(beg, it, cmp);
        VmaQuickSort<Iterator, Compare>(it + 1, end, cmp);
    }
}

#define VMA_SORT(beg, end, cmp) VmaQuickSort(beg, end, cmp)

#endif // #ifndef VMA_SORT

/*
Returns true if two memory blocks occupy overlapping pages.
ResourceA must be in less memory offset than ResourceB.

Algorithm is based on "Vulkan 1.0.39 - A Specification (with all registered Vulkan extensions)"
chapter 11.6 "Resource Memory Association", paragraph "Buffer-Image Granularity".
*/
static inline bool VmaBlocksOnSamePage(
    VkDeviceSize resourceAOffset,
    VkDeviceSize resourceASize,
    VkDeviceSize resourceBOffset,
    VkDeviceSize pageSize)
{
    VMA_ASSERT(resourceAOffset + resourceASize <= resourceBOffset && resourceASize > 0 && pageSize > 0);
    VkDeviceSize resourceAEnd = resourceAOffset + resourceASize - 1;
    VkDeviceSize resourceAEndPage = resourceAEnd & ~(pageSize - 1);
    VkDeviceSize resourceBStart = resourceBOffset;
    VkDeviceSize resourceBStartPage = resourceBStart & ~(pageSize - 1);
    return resourceAEndPage == resourceBStartPage;
}

enum VmaSuballocationType
{
    VMA_SUBALLOCATION_TYPE_FREE = 0,
    VMA_SUBALLOCATION_TYPE_UNKNOWN = 1,
    VMA_SUBALLOCATION_TYPE_BUFFER = 2,
    VMA_SUBALLOCATION_TYPE_IMAGE_UNKNOWN = 3,
    VMA_SUBALLOCATION_TYPE_IMAGE_LINEAR = 4,
    VMA_SUBALLOCATION_TYPE_IMAGE_OPTIMAL = 5,
    VMA_SUBALLOCATION_TYPE_MAX_ENUM = 0x7FFFFFFF
};

/*
Returns true if given suballocation types could conflict and must respect
VkPhysicalDeviceLimits::bufferImageGranularity. They conflict if one is buffer
or linear image and another one is optimal image. If type is unknown, behave
conservatively.
*/
static inline bool VmaIsBufferImageGranularityConflict(
    VmaSuballocationType suballocType1,
    VmaSuballocationType suballocType2)
{
    if(suballocType1 > suballocType2)
    {
        VMA_SWAP(suballocType1, suballocType2);
    }
    
    switch(suballocType1)
    {
    case VMA_SUBALLOCATION_TYPE_FREE:
        return false;
    case VMA_SUBALLOCATION_TYPE_UNKNOWN:
        return true;
    case VMA_SUBALLOCATION_TYPE_BUFFER:
        return
            suballocType2 == VMA_SUBALLOCATION_TYPE_IMAGE_UNKNOWN ||
            suballocType2 == VMA_SUBALLOCATION_TYPE_IMAGE_OPTIMAL;
    case VMA_SUBALLOCATION_TYPE_IMAGE_UNKNOWN:
        return
            suballocType2 == VMA_SUBALLOCATION_TYPE_IMAGE_UNKNOWN ||
            suballocType2 == VMA_SUBALLOCATION_TYPE_IMAGE_LINEAR ||
            suballocType2 == VMA_SUBALLOCATION_TYPE_IMAGE_OPTIMAL;
    case VMA_SUBALLOCATION_TYPE_IMAGE_LINEAR:
        return
            suballocType2 == VMA_SUBALLOCATION_TYPE_IMAGE_OPTIMAL;
    case VMA_SUBALLOCATION_TYPE_IMAGE_OPTIMAL:
        return false;
    default:
        VMA_ASSERT(0);
        return true;
    }
}

static void VmaWriteMagicValue(void* pData, VkDeviceSize offset)
{
    uint32_t* pDst = (uint32_t*)((char*)pData + offset);
    const size_t numberCount = VMA_DEBUG_MARGIN / sizeof(uint32_t);
    for(size_t i = 0; i < numberCount; ++i, ++pDst)
    {
        *pDst = VMA_CORRUPTION_DETECTION_MAGIC_VALUE;
    }
}

static bool VmaValidateMagicValue(const void* pData, VkDeviceSize offset)
{
    const uint32_t* pSrc = (const uint32_t*)((const char*)pData + offset);
    const size_t numberCount = VMA_DEBUG_MARGIN / sizeof(uint32_t);
    for(size_t i = 0; i < numberCount; ++i, ++pSrc)
    {
        if(*pSrc != VMA_CORRUPTION_DETECTION_MAGIC_VALUE)
        {
            return false;
        }
    }
    return true;
}

/*
Fills structure with parameters of an example buffer to be used for transfers
during GPU memory defragmentation.
*/
static void VmaFillGpuDefragmentationBufferCreateInfo(VkBufferCreateInfo& outBufCreateInfo)
{
    memset(&outBufCreateInfo, 0, sizeof(outBufCreateInfo));
    outBufCreateInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
    outBufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
    outBufCreateInfo.size = (VkDeviceSize)VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE; // Example size.
}

// Helper RAII class to lock a mutex in constructor and unlock it in destructor (at the end of scope).
struct VmaMutexLock
{
    VMA_CLASS_NO_COPY(VmaMutexLock)
public:
    VmaMutexLock(VMA_MUTEX& mutex, bool useMutex = true) :
        m_pMutex(useMutex ? &mutex : VMA_NULL)
    { if(m_pMutex) { m_pMutex->Lock(); } }
    ~VmaMutexLock()
    { if(m_pMutex) { m_pMutex->Unlock(); } }
private:
    VMA_MUTEX* m_pMutex;
};

// Helper RAII class to lock a RW mutex in constructor and unlock it in destructor (at the end of scope), for reading.
struct VmaMutexLockRead
{
    VMA_CLASS_NO_COPY(VmaMutexLockRead)
public:
    VmaMutexLockRead(VMA_RW_MUTEX& mutex, bool useMutex) :
        m_pMutex(useMutex ? &mutex : VMA_NULL)
    { if(m_pMutex) { m_pMutex->LockRead(); } }
    ~VmaMutexLockRead() { if(m_pMutex) { m_pMutex->UnlockRead(); } }
private:
    VMA_RW_MUTEX* m_pMutex;
};

// Helper RAII class to lock a RW mutex in constructor and unlock it in destructor (at the end of scope), for writing.
struct VmaMutexLockWrite
{
    VMA_CLASS_NO_COPY(VmaMutexLockWrite)
public:
    VmaMutexLockWrite(VMA_RW_MUTEX& mutex, bool useMutex) :
        m_pMutex(useMutex ? &mutex : VMA_NULL)
    { if(m_pMutex) { m_pMutex->LockWrite(); } }
    ~VmaMutexLockWrite() { if(m_pMutex) { m_pMutex->UnlockWrite(); } }
private:
    VMA_RW_MUTEX* m_pMutex;
};

#if VMA_DEBUG_GLOBAL_MUTEX
    static VMA_MUTEX gDebugGlobalMutex;
    #define VMA_DEBUG_GLOBAL_MUTEX_LOCK VmaMutexLock debugGlobalMutexLock(gDebugGlobalMutex, true);
#else
    #define VMA_DEBUG_GLOBAL_MUTEX_LOCK
#endif

// Minimum size of a free suballocation to register it in the free suballocation collection.
static const VkDeviceSize VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER = 16;

/*
Performs binary search and returns iterator to first element that is greater or
equal to (key), according to comparison (cmp).

Cmp should return true if first argument is less than second argument.

Returned value is the found element, if present in the collection or place where
new element with value (key) should be inserted.
*/
template <typename CmpLess, typename IterT, typename KeyT>
static IterT VmaBinaryFindFirstNotLess(IterT beg, IterT end, const KeyT &key, CmpLess cmp)
{
    size_t down = 0, up = (end - beg);
    while(down < up)
    {
        const size_t mid = (down + up) / 2;
        if(cmp(*(beg+mid), key))
        {
            down = mid + 1;
        }
        else
        {
            up = mid;
        }
    }
    return beg + down;
}

/*
Returns true if all pointers in the array are not-null and unique.
Warning! O(n^2) complexity. Use only inside VMA_HEAVY_ASSERT.
T must be pointer type, e.g. VmaAllocation, VmaPool.
*/
template<typename T>
static bool VmaValidatePointerArray(uint32_t count, const T* arr)
{
    for(uint32_t i = 0; i < count; ++i)
    {
        const T iPtr = arr[i];
        if(iPtr == VMA_NULL)
        {
            return false;
        }
        for(uint32_t j = i + 1; j < count; ++j)
        {
            if(iPtr == arr[j])
            {
                return false;
            }
        }
    }
    return true;
}

// Memory allocation

static void* VmaMalloc(const VkAllocationCallbacks* pAllocationCallbacks, size_t size, size_t alignment)
{
    if((pAllocationCallbacks != VMA_NULL) &&
        (pAllocationCallbacks->pfnAllocation != VMA_NULL))
    {
        return (*pAllocationCallbacks->pfnAllocation)(
            pAllocationCallbacks->pUserData,
            size,
            alignment,
            VK_SYSTEM_ALLOCATION_SCOPE_OBJECT);
    }
    else
    {
        return VMA_SYSTEM_ALIGNED_MALLOC(size, alignment);
    }
}

static void VmaFree(const VkAllocationCallbacks* pAllocationCallbacks, void* ptr)
{
    if((pAllocationCallbacks != VMA_NULL) &&
        (pAllocationCallbacks->pfnFree != VMA_NULL))
    {
        (*pAllocationCallbacks->pfnFree)(pAllocationCallbacks->pUserData, ptr);
    }
    else
    {
        VMA_SYSTEM_FREE(ptr);
    }
}

template<typename T>
static T* VmaAllocate(const VkAllocationCallbacks* pAllocationCallbacks)
{
    return (T*)VmaMalloc(pAllocationCallbacks, sizeof(T), VMA_ALIGN_OF(T));
}

template<typename T>
static T* VmaAllocateArray(const VkAllocationCallbacks* pAllocationCallbacks, size_t count)
{
    return (T*)VmaMalloc(pAllocationCallbacks, sizeof(T) * count, VMA_ALIGN_OF(T));
}

#define vma_new(allocator, type)   new(VmaAllocate<type>(allocator))(type)

#define vma_new_array(allocator, type, count)   new(VmaAllocateArray<type>((allocator), (count)))(type)

template<typename T>
static void vma_delete(const VkAllocationCallbacks* pAllocationCallbacks, T* ptr)
{
    ptr->~T();
    VmaFree(pAllocationCallbacks, ptr);
}

template<typename T>
static void vma_delete_array(const VkAllocationCallbacks* pAllocationCallbacks, T* ptr, size_t count)
{
    if(ptr != VMA_NULL)
    {
        for(size_t i = count; i--; )
        {
            ptr[i].~T();
        }
        VmaFree(pAllocationCallbacks, ptr);
    }
}

// STL-compatible allocator.
template<typename T>
class VmaStlAllocator
{
public:
    const VkAllocationCallbacks* const m_pCallbacks;
    typedef T value_type;
    
    VmaStlAllocator(const VkAllocationCallbacks* pCallbacks) : m_pCallbacks(pCallbacks) { }
    template<typename U> VmaStlAllocator(const VmaStlAllocator<U>& src) : m_pCallbacks(src.m_pCallbacks) { }

    T* allocate(size_t n) { return VmaAllocateArray<T>(m_pCallbacks, n); }
    void deallocate(T* p, size_t n) { VmaFree(m_pCallbacks, p); }

    template<typename U>
    bool operator==(const VmaStlAllocator<U>& rhs) const
    {
        return m_pCallbacks == rhs.m_pCallbacks;
    }
    template<typename U>
    bool operator!=(const VmaStlAllocator<U>& rhs) const
    {
        return m_pCallbacks != rhs.m_pCallbacks;
    }

    VmaStlAllocator& operator=(const VmaStlAllocator& x) = delete;
};

#if VMA_USE_STL_VECTOR

#define VmaVector std::vector

template<typename T, typename allocatorT>
static void VmaVectorInsert(std::vector<T, allocatorT>& vec, size_t index, const T& item)
{
    vec.insert(vec.begin() + index, item);
}

template<typename T, typename allocatorT>
static void VmaVectorRemove(std::vector<T, allocatorT>& vec, size_t index)
{
    vec.erase(vec.begin() + index);
}

#else // #if VMA_USE_STL_VECTOR

/* Class with interface compatible with subset of std::vector.
T must be POD because constructors and destructors are not called and memcpy is
used for these objects. */
template<typename T, typename AllocatorT>
class VmaVector
{
public:
    typedef T value_type;

    VmaVector(const AllocatorT& allocator) :
        m_Allocator(allocator),
        m_pArray(VMA_NULL),
        m_Count(0),
        m_Capacity(0)
    {
    }

    VmaVector(size_t count, const AllocatorT& allocator) :
        m_Allocator(allocator),
        m_pArray(count ? (T*)VmaAllocateArray<T>(allocator.m_pCallbacks, count) : VMA_NULL),
        m_Count(count),
        m_Capacity(count)
    {
    }
    
    VmaVector(const VmaVector<T, AllocatorT>& src) :
        m_Allocator(src.m_Allocator),
        m_pArray(src.m_Count ? (T*)VmaAllocateArray<T>(src.m_Allocator.m_pCallbacks, src.m_Count) : VMA_NULL),
        m_Count(src.m_Count),
        m_Capacity(src.m_Count)
    {
        if(m_Count != 0)
        {
            memcpy(m_pArray, src.m_pArray, m_Count * sizeof(T));
        }
    }
    
    ~VmaVector()
    {
        VmaFree(m_Allocator.m_pCallbacks, m_pArray);
    }

    VmaVector& operator=(const VmaVector<T, AllocatorT>& rhs)
    {
        if(&rhs != this)
        {
            resize(rhs.m_Count);
            if(m_Count != 0)
            {
                memcpy(m_pArray, rhs.m_pArray, m_Count * sizeof(T));
            }
        }
        return *this;
    }
    
    bool empty() const { return m_Count == 0; }
    size_t size() const { return m_Count; }
    T* data() { return m_pArray; }
    const T* data() const { return m_pArray; }
    
    T& operator[](size_t index)
    {
        VMA_HEAVY_ASSERT(index < m_Count);
        return m_pArray[index];
    }
    const T& operator[](size_t index) const
    {
        VMA_HEAVY_ASSERT(index < m_Count);
        return m_pArray[index];
    }

    T& front()
    {
        VMA_HEAVY_ASSERT(m_Count > 0);
        return m_pArray[0];
    }
    const T& front() const
    {
        VMA_HEAVY_ASSERT(m_Count > 0);
        return m_pArray[0];
    }
    T& back()
    {
        VMA_HEAVY_ASSERT(m_Count > 0);
        return m_pArray[m_Count - 1];
    }
    const T& back() const
    {
        VMA_HEAVY_ASSERT(m_Count > 0);
        return m_pArray[m_Count - 1];
    }

    void reserve(size_t newCapacity, bool freeMemory = false)
    {
        newCapacity = VMA_MAX(newCapacity, m_Count);
        
        if((newCapacity < m_Capacity) && !freeMemory)
        {
            newCapacity = m_Capacity;
        }
        
        if(newCapacity != m_Capacity)
        {
            T* const newArray = newCapacity ? VmaAllocateArray<T>(m_Allocator, newCapacity) : VMA_NULL;
            if(m_Count != 0)
            {
                memcpy(newArray, m_pArray, m_Count * sizeof(T));
            }
            VmaFree(m_Allocator.m_pCallbacks, m_pArray);
            m_Capacity = newCapacity;
            m_pArray = newArray;
        }
    }

    void resize(size_t newCount, bool freeMemory = false)
    {
        size_t newCapacity = m_Capacity;
        if(newCount > m_Capacity)
        {
            newCapacity = VMA_MAX(newCount, VMA_MAX(m_Capacity * 3 / 2, (size_t)8));
        }
        else if(freeMemory)
        {
            newCapacity = newCount;
        }

        if(newCapacity != m_Capacity)
        {
            T* const newArray = newCapacity ? VmaAllocateArray<T>(m_Allocator.m_pCallbacks, newCapacity) : VMA_NULL;
            const size_t elementsToCopy = VMA_MIN(m_Count, newCount);
            if(elementsToCopy != 0)
            {
                memcpy(newArray, m_pArray, elementsToCopy * sizeof(T));
            }
            VmaFree(m_Allocator.m_pCallbacks, m_pArray);
            m_Capacity = newCapacity;
            m_pArray = newArray;
        }

        m_Count = newCount;
    }

    void clear(bool freeMemory = false)
    {
        resize(0, freeMemory);
    }

    void insert(size_t index, const T& src)
    {
        VMA_HEAVY_ASSERT(index <= m_Count);
        const size_t oldCount = size();
        resize(oldCount + 1);
        if(index < oldCount)
        {
            memmove(m_pArray + (index + 1), m_pArray + index, (oldCount - index) * sizeof(T));
        }
        m_pArray[index] = src;
    }

    void remove(size_t index)
    {
        VMA_HEAVY_ASSERT(index < m_Count);
        const size_t oldCount = size();
        if(index < oldCount - 1)
        {
            memmove(m_pArray + index, m_pArray + (index + 1), (oldCount - index - 1) * sizeof(T));
        }
        resize(oldCount - 1);
    }

    void push_back(const T& src)
    {
        const size_t newIndex = size();
        resize(newIndex + 1);
        m_pArray[newIndex] = src;
    }

    void pop_back()
    {
        VMA_HEAVY_ASSERT(m_Count > 0);
        resize(size() - 1);
    }

    void push_front(const T& src)
    {
        insert(0, src);
    }

    void pop_front()
    {
        VMA_HEAVY_ASSERT(m_Count > 0);
        remove(0);
    }

    typedef T* iterator;

    iterator begin() { return m_pArray; }
    iterator end() { return m_pArray + m_Count; }

private:
    AllocatorT m_Allocator;
    T* m_pArray;
    size_t m_Count;
    size_t m_Capacity;
};

template<typename T, typename allocatorT>
static void VmaVectorInsert(VmaVector<T, allocatorT>& vec, size_t index, const T& item)
{
    vec.insert(index, item);
}

template<typename T, typename allocatorT>
static void VmaVectorRemove(VmaVector<T, allocatorT>& vec, size_t index)
{
    vec.remove(index);
}

#endif // #if VMA_USE_STL_VECTOR

template<typename CmpLess, typename VectorT>
size_t VmaVectorInsertSorted(VectorT& vector, const typename VectorT::value_type& value)
{
    const size_t indexToInsert = VmaBinaryFindFirstNotLess(
        vector.data(),
        vector.data() + vector.size(),
        value,
        CmpLess()) - vector.data();
    VmaVectorInsert(vector, indexToInsert, value);
    return indexToInsert;
}

template<typename CmpLess, typename VectorT>
bool VmaVectorRemoveSorted(VectorT& vector, const typename VectorT::value_type& value)
{
    CmpLess comparator;
    typename VectorT::iterator it = VmaBinaryFindFirstNotLess(
        vector.begin(),
        vector.end(),
        value,
        comparator);
    if((it != vector.end()) && !comparator(*it, value) && !comparator(value, *it))
    {
        size_t indexToRemove = it - vector.begin();
        VmaVectorRemove(vector, indexToRemove);
        return true;
    }
    return false;
}

template<typename CmpLess, typename IterT, typename KeyT>
IterT VmaVectorFindSorted(const IterT& beg, const IterT& end, const KeyT& value)
{
    CmpLess comparator;
    IterT it = VmaBinaryFindFirstNotLess<CmpLess, IterT, KeyT>(
        beg, end, value, comparator);
    if(it == end ||
        (!comparator(*it, value) && !comparator(value, *it)))
    {
        return it;
    }
    return end;
}

// class VmaPoolAllocator

/*
Allocator for objects of type T using a list of arrays (pools) to speed up
allocation. Number of elements that can be allocated is not bounded because
allocator can create multiple blocks.
*/
template<typename T>
class VmaPoolAllocator
{
    VMA_CLASS_NO_COPY(VmaPoolAllocator)
public:
    VmaPoolAllocator(const VkAllocationCallbacks* pAllocationCallbacks, uint32_t firstBlockCapacity);
    ~VmaPoolAllocator();
    void Clear();
    T* Alloc();
    void Free(T* ptr);

private:
    union Item
    {
        uint32_t NextFreeIndex;
        T Value;
    };

    struct ItemBlock
    {
        Item* pItems;
        uint32_t Capacity;
        uint32_t FirstFreeIndex;
    };
    
    const VkAllocationCallbacks* m_pAllocationCallbacks;
    const uint32_t m_FirstBlockCapacity;
    VmaVector< ItemBlock, VmaStlAllocator<ItemBlock> > m_ItemBlocks;

    ItemBlock& CreateNewBlock();
};

template<typename T>
VmaPoolAllocator<T>::VmaPoolAllocator(const VkAllocationCallbacks* pAllocationCallbacks, uint32_t firstBlockCapacity) :
    m_pAllocationCallbacks(pAllocationCallbacks),
    m_FirstBlockCapacity(firstBlockCapacity),
    m_ItemBlocks(VmaStlAllocator<ItemBlock>(pAllocationCallbacks))
{
    VMA_ASSERT(m_FirstBlockCapacity > 1);
}

template<typename T>
VmaPoolAllocator<T>::~VmaPoolAllocator()
{
    Clear();
}

template<typename T>
void VmaPoolAllocator<T>::Clear()
{
    for(size_t i = m_ItemBlocks.size(); i--; )
        vma_delete_array(m_pAllocationCallbacks, m_ItemBlocks[i].pItems, m_ItemBlocks[i].Capacity);
    m_ItemBlocks.clear();
}

template<typename T>
T* VmaPoolAllocator<T>::Alloc()
{
    for(size_t i = m_ItemBlocks.size(); i--; )
    {
        ItemBlock& block = m_ItemBlocks[i];
        // This block has some free items: Use first one.
        if(block.FirstFreeIndex != UINT32_MAX)
        {
            Item* const pItem = &block.pItems[block.FirstFreeIndex];
            block.FirstFreeIndex = pItem->NextFreeIndex;
            return &pItem->Value;
        }
    }

    // No block has free item: Create new one and use it.
    ItemBlock& newBlock = CreateNewBlock();
    Item* const pItem = &newBlock.pItems[0];
    newBlock.FirstFreeIndex = pItem->NextFreeIndex;
    return &pItem->Value;
}

template<typename T>
void VmaPoolAllocator<T>::Free(T* ptr)
{
    // Search all memory blocks to find ptr.
    for(size_t i = m_ItemBlocks.size(); i--; )
    {
        ItemBlock& block = m_ItemBlocks[i];
        
        // Casting to union.
        Item* pItemPtr;
        memcpy(&pItemPtr, &ptr, sizeof(pItemPtr));
        
        // Check if pItemPtr is in address range of this block.
        if((pItemPtr >= block.pItems) && (pItemPtr < block.pItems + block.Capacity))
        {
            const uint32_t index = static_cast<uint32_t>(pItemPtr - block.pItems);
            pItemPtr->NextFreeIndex = block.FirstFreeIndex;
            block.FirstFreeIndex = index;
            return;
        }
    }
    VMA_ASSERT(0 && "Pointer doesn't belong to this memory pool.");
}

template<typename T>
typename VmaPoolAllocator<T>::ItemBlock& VmaPoolAllocator<T>::CreateNewBlock()
{
    const uint32_t newBlockCapacity = m_ItemBlocks.empty() ?
        m_FirstBlockCapacity : m_ItemBlocks.back().Capacity * 3 / 2;

    const ItemBlock newBlock = {
        vma_new_array(m_pAllocationCallbacks, Item, newBlockCapacity),
        newBlockCapacity,
        0 };

    m_ItemBlocks.push_back(newBlock);

    // Setup singly-linked list of all free items in this block.
    for(uint32_t i = 0; i < newBlockCapacity - 1; ++i)
        newBlock.pItems[i].NextFreeIndex = i + 1;
    newBlock.pItems[newBlockCapacity - 1].NextFreeIndex = UINT32_MAX;
    return m_ItemBlocks.back();
}

// class VmaRawList, VmaList

#if VMA_USE_STL_LIST

#define VmaList std::list

#else // #if VMA_USE_STL_LIST

template<typename T>
struct VmaListItem
{
    VmaListItem* pPrev;
    VmaListItem* pNext;
    T Value;
};

// Doubly linked list.
template<typename T>
class VmaRawList
{
    VMA_CLASS_NO_COPY(VmaRawList)
public:
    typedef VmaListItem<T> ItemType;

    VmaRawList(const VkAllocationCallbacks* pAllocationCallbacks);
    ~VmaRawList();
    void Clear();

    size_t GetCount() const { return m_Count; }
    bool IsEmpty() const { return m_Count == 0; }

    ItemType* Front() { return m_pFront; }
    const ItemType* Front() const { return m_pFront; }
    ItemType* Back() { return m_pBack; }
    const ItemType* Back() const { return m_pBack; }

    ItemType* PushBack();
    ItemType* PushFront();
    ItemType* PushBack(const T& value);
    ItemType* PushFront(const T& value);
    void PopBack();
    void PopFront();
    
    // Item can be null - it means PushBack.
    ItemType* InsertBefore(ItemType* pItem);
    // Item can be null - it means PushFront.
    ItemType* InsertAfter(ItemType* pItem);

    ItemType* InsertBefore(ItemType* pItem, const T& value);
    ItemType* InsertAfter(ItemType* pItem, const T& value);

    void Remove(ItemType* pItem);

private:
    const VkAllocationCallbacks* const m_pAllocationCallbacks;
    VmaPoolAllocator<ItemType> m_ItemAllocator;
    ItemType* m_pFront;
    ItemType* m_pBack;
    size_t m_Count;
};

template<typename T>
VmaRawList<T>::VmaRawList(const VkAllocationCallbacks* pAllocationCallbacks) :
    m_pAllocationCallbacks(pAllocationCallbacks),
    m_ItemAllocator(pAllocationCallbacks, 128),
    m_pFront(VMA_NULL),
    m_pBack(VMA_NULL),
    m_Count(0)
{
}

template<typename T>
VmaRawList<T>::~VmaRawList()
{
    // Intentionally not calling Clear, because that would be unnecessary
    // computations to return all items to m_ItemAllocator as free.
}

template<typename T>
void VmaRawList<T>::Clear()
{
    if(IsEmpty() == false)
    {
        ItemType* pItem = m_pBack;
        while(pItem != VMA_NULL)
        {
            ItemType* const pPrevItem = pItem->pPrev;
            m_ItemAllocator.Free(pItem);
            pItem = pPrevItem;
        }
        m_pFront = VMA_NULL;
        m_pBack = VMA_NULL;
        m_Count = 0;
    }
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushBack()
{
    ItemType* const pNewItem = m_ItemAllocator.Alloc();
    pNewItem->pNext = VMA_NULL;
    if(IsEmpty())
    {
        pNewItem->pPrev = VMA_NULL;
        m_pFront = pNewItem;
        m_pBack = pNewItem;
        m_Count = 1;
    }
    else
    {
        pNewItem->pPrev = m_pBack;
        m_pBack->pNext = pNewItem;
        m_pBack = pNewItem;
        ++m_Count;
    }
    return pNewItem;
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushFront()
{
    ItemType* const pNewItem = m_ItemAllocator.Alloc();
    pNewItem->pPrev = VMA_NULL;
    if(IsEmpty())
    {
        pNewItem->pNext = VMA_NULL;
        m_pFront = pNewItem;
        m_pBack = pNewItem;
        m_Count = 1;
    }
    else
    {
        pNewItem->pNext = m_pFront;
        m_pFront->pPrev = pNewItem;
        m_pFront = pNewItem;
        ++m_Count;
    }
    return pNewItem;
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushBack(const T& value)
{
    ItemType* const pNewItem = PushBack();
    pNewItem->Value = value;
    return pNewItem;
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushFront(const T& value)
{
    ItemType* const pNewItem = PushFront();
    pNewItem->Value = value;
    return pNewItem;
}

template<typename T>
void VmaRawList<T>::PopBack()
{
    VMA_HEAVY_ASSERT(m_Count > 0);
    ItemType* const pBackItem = m_pBack;
    ItemType* const pPrevItem = pBackItem->pPrev;
    if(pPrevItem != VMA_NULL)
    {
        pPrevItem->pNext = VMA_NULL;
    }
    m_pBack = pPrevItem;
    m_ItemAllocator.Free(pBackItem);
    --m_Count;
}

template<typename T>
void VmaRawList<T>::PopFront()
{
    VMA_HEAVY_ASSERT(m_Count > 0);
    ItemType* const pFrontItem = m_pFront;
    ItemType* const pNextItem = pFrontItem->pNext;
    if(pNextItem != VMA_NULL)
    {
        pNextItem->pPrev = VMA_NULL;
    }
    m_pFront = pNextItem;
    m_ItemAllocator.Free(pFrontItem);
    --m_Count;
}

template<typename T>
void VmaRawList<T>::Remove(ItemType* pItem)
{
    VMA_HEAVY_ASSERT(pItem != VMA_NULL);
    VMA_HEAVY_ASSERT(m_Count > 0);

    if(pItem->pPrev != VMA_NULL)
    {
        pItem->pPrev->pNext = pItem->pNext;
    }
    else
    {
        VMA_HEAVY_ASSERT(m_pFront == pItem);
        m_pFront = pItem->pNext;
    }

    if(pItem->pNext != VMA_NULL)
    {
        pItem->pNext->pPrev = pItem->pPrev;
    }
    else
    {
        VMA_HEAVY_ASSERT(m_pBack == pItem);
        m_pBack = pItem->pPrev;
    }

    m_ItemAllocator.Free(pItem);
    --m_Count;
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertBefore(ItemType* pItem)
{
    if(pItem != VMA_NULL)
    {
        ItemType* const prevItem = pItem->pPrev;
        ItemType* const newItem = m_ItemAllocator.Alloc();
        newItem->pPrev = prevItem;
        newItem->pNext = pItem;
        pItem->pPrev = newItem;
        if(prevItem != VMA_NULL)
        {
            prevItem->pNext = newItem;
        }
        else
        {
            VMA_HEAVY_ASSERT(m_pFront == pItem);
            m_pFront = newItem;
        }
        ++m_Count;
        return newItem;
    }
    else
        return PushBack();
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertAfter(ItemType* pItem)
{
    if(pItem != VMA_NULL)
    {
        ItemType* const nextItem = pItem->pNext;
        ItemType* const newItem = m_ItemAllocator.Alloc();
        newItem->pNext = nextItem;
        newItem->pPrev = pItem;
        pItem->pNext = newItem;
        if(nextItem != VMA_NULL)
        {
            nextItem->pPrev = newItem;
        }
        else
        {
            VMA_HEAVY_ASSERT(m_pBack == pItem);
            m_pBack = newItem;
        }
        ++m_Count;
        return newItem;
    }
    else
        return PushFront();
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertBefore(ItemType* pItem, const T& value)
{
    ItemType* const newItem = InsertBefore(pItem);
    newItem->Value = value;
    return newItem;
}

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertAfter(ItemType* pItem, const T& value)
{
    ItemType* const newItem = InsertAfter(pItem);
    newItem->Value = value;
    return newItem;
}

template<typename T, typename AllocatorT>
class VmaList
{
    VMA_CLASS_NO_COPY(VmaList)
public:
    class iterator
    {
    public:
        iterator() :
            m_pList(VMA_NULL),
            m_pItem(VMA_NULL)
        {
        }

        T& operator*() const
        {
            VMA_HEAVY_ASSERT(m_pItem != VMA_NULL);
            return m_pItem->Value;
        }
        T* operator->() const
        {
            VMA_HEAVY_ASSERT(m_pItem != VMA_NULL);
            return &m_pItem->Value;
        }

        iterator& operator++()
        {
            VMA_HEAVY_ASSERT(m_pItem != VMA_NULL);
            m_pItem = m_pItem->pNext;
            return *this;
        }
        iterator& operator--()
        {
            if(m_pItem != VMA_NULL)
            {
                m_pItem = m_pItem->pPrev;
            }
            else
            {
                VMA_HEAVY_ASSERT(!m_pList->IsEmpty());
                m_pItem = m_pList->Back();
            }
            return *this;
        }

        iterator operator++(int)
        {
            iterator result = *this;
            ++*this;
            return result;
        }
        iterator operator--(int)
        {
            iterator result = *this;
            --*this;
            return result;
        }

        bool operator==(const iterator& rhs) const
        {
            VMA_HEAVY_ASSERT(m_pList == rhs.m_pList);
            return m_pItem == rhs.m_pItem;
        }
        bool operator!=(const iterator& rhs) const
        {
            VMA_HEAVY_ASSERT(m_pList == rhs.m_pList);
            return m_pItem != rhs.m_pItem;
        }
        
    private:
        VmaRawList<T>* m_pList;
        VmaListItem<T>* m_pItem;

        iterator(VmaRawList<T>* pList, VmaListItem<T>* pItem) :
            m_pList(pList),
            m_pItem(pItem)
        {
        }

        friend class VmaList<T, AllocatorT>;
    };

    class const_iterator
    {
    public:
        const_iterator() :
            m_pList(VMA_NULL),
            m_pItem(VMA_NULL)
        {
        }

        const_iterator(const iterator& src) :
            m_pList(src.m_pList),
            m_pItem(src.m_pItem)
        {
        }
        
        const T& operator*() const
        {
            VMA_HEAVY_ASSERT(m_pItem != VMA_NULL);
            return m_pItem->Value;
        }
        const T* operator->() const
        {
            VMA_HEAVY_ASSERT(m_pItem != VMA_NULL);
            return &m_pItem->Value;
        }

        const_iterator& operator++()
        {
            VMA_HEAVY_ASSERT(m_pItem != VMA_NULL);
            m_pItem = m_pItem->pNext;
            return *this;
        }
        const_iterator& operator--()
        {
            if(m_pItem != VMA_NULL)
            {
                m_pItem = m_pItem->pPrev;
            }
            else
            {
                VMA_HEAVY_ASSERT(!m_pList->IsEmpty());
                m_pItem = m_pList->Back();
            }
            return *this;
        }

        const_iterator operator++(int)
        {
            const_iterator result = *this;
            ++*this;
            return result;
        }
        const_iterator operator--(int)
        {
            const_iterator result = *this;
            --*this;
            return result;
        }

        bool operator==(const const_iterator& rhs) const
        {
            VMA_HEAVY_ASSERT(m_pList == rhs.m_pList);
            return m_pItem == rhs.m_pItem;
        }
        bool operator!=(const const_iterator& rhs) const
        {
            VMA_HEAVY_ASSERT(m_pList == rhs.m_pList);
            return m_pItem != rhs.m_pItem;
        }
        
    private:
        const_iterator(const VmaRawList<T>* pList, const VmaListItem<T>* pItem) :
            m_pList(pList),
            m_pItem(pItem)
        {
        }

        const VmaRawList<T>* m_pList;
        const VmaListItem<T>* m_pItem;

        friend class VmaList<T, AllocatorT>;
    };

    VmaList(const AllocatorT& allocator) : m_RawList(allocator.m_pCallbacks) { }

    bool empty() const { return m_RawList.IsEmpty(); }
    size_t size() const { return m_RawList.GetCount(); }

    iterator begin() { return iterator(&m_RawList, m_RawList.Front()); }
    iterator end() { return iterator(&m_RawList, VMA_NULL); }

    const_iterator cbegin() const { return const_iterator(&m_RawList, m_RawList.Front()); }
    const_iterator cend() const { return const_iterator(&m_RawList, VMA_NULL); }

    void clear() { m_RawList.Clear(); }
    void push_back(const T& value) { m_RawList.PushBack(value); }
    void erase(iterator it) { m_RawList.Remove(it.m_pItem); }
    iterator insert(iterator it, const T& value) { return iterator(&m_RawList, m_RawList.InsertBefore(it.m_pItem, value)); }

private:
    VmaRawList<T> m_RawList;
};

#endif // #if VMA_USE_STL_LIST

// class VmaMap

// Unused in this version.
#if 0

#if VMA_USE_STL_UNORDERED_MAP

#define VmaPair std::pair

#define VMA_MAP_TYPE(KeyT, ValueT) \
    std::unordered_map< KeyT, ValueT, std::hash<KeyT>, std::equal_to<KeyT>, VmaStlAllocator< std::pair<KeyT, ValueT> > >

#else // #if VMA_USE_STL_UNORDERED_MAP

template<typename T1, typename T2>
struct VmaPair
{
    T1 first;
    T2 second;

    VmaPair() : first(), second() { }
    VmaPair(const T1& firstSrc, const T2& secondSrc) : first(firstSrc), second(secondSrc) { }
};

/* Class compatible with subset of interface of std::unordered_map.
KeyT, ValueT must be POD because they will be stored in VmaVector.
*/
template<typename KeyT, typename ValueT>
class VmaMap
{
public:
    typedef VmaPair<KeyT, ValueT> PairType;
    typedef PairType* iterator;

    VmaMap(const VmaStlAllocator<PairType>& allocator) : m_Vector(allocator) { }

    iterator begin() { return m_Vector.begin(); }
    iterator end() { return m_Vector.end(); }

    void insert(const PairType& pair);
    iterator find(const KeyT& key);
    void erase(iterator it);
    
private:
    VmaVector< PairType, VmaStlAllocator<PairType> > m_Vector;
};

#define VMA_MAP_TYPE(KeyT, ValueT) VmaMap<KeyT, ValueT>

template<typename FirstT, typename SecondT>
struct VmaPairFirstLess
{
    bool operator()(const VmaPair<FirstT, SecondT>& lhs, const VmaPair<FirstT, SecondT>& rhs) const
    {
        return lhs.first < rhs.first;
    }
    bool operator()(const VmaPair<FirstT, SecondT>& lhs, const FirstT& rhsFirst) const
    {
        return lhs.first < rhsFirst;
    }
};

template<typename KeyT, typename ValueT>
void VmaMap<KeyT, ValueT>::insert(const PairType& pair)
{
    const size_t indexToInsert = VmaBinaryFindFirstNotLess(
        m_Vector.data(),
        m_Vector.data() + m_Vector.size(),
        pair,
        VmaPairFirstLess<KeyT, ValueT>()) - m_Vector.data();
    VmaVectorInsert(m_Vector, indexToInsert, pair);
}

template<typename KeyT, typename ValueT>
VmaPair<KeyT, ValueT>* VmaMap<KeyT, ValueT>::find(const KeyT& key)
{
    PairType* it = VmaBinaryFindFirstNotLess(
        m_Vector.data(),
        m_Vector.data() + m_Vector.size(),
        key,
        VmaPairFirstLess<KeyT, ValueT>());
    if((it != m_Vector.end()) && (it->first == key))
    {
        return it;
    }
    else
    {
        return m_Vector.end();
    }
}

template<typename KeyT, typename ValueT>
void VmaMap<KeyT, ValueT>::erase(iterator it)
{
    VmaVectorRemove(m_Vector, it - m_Vector.begin());
}

#endif // #if VMA_USE_STL_UNORDERED_MAP

#endif // #if 0


class VmaDeviceMemoryBlock;

enum VMA_CACHE_OPERATION { VMA_CACHE_FLUSH, VMA_CACHE_INVALIDATE };

struct VmaAllocation_T
{
private:
    static const uint8_t MAP_COUNT_FLAG_PERSISTENT_MAP = 0x80;

    enum FLAGS
    {
        FLAG_USER_DATA_STRING = 0x01,
    };

public:
    enum ALLOCATION_TYPE
    {
        ALLOCATION_TYPE_NONE,
        ALLOCATION_TYPE_BLOCK,
        ALLOCATION_TYPE_DEDICATED,
    };

    /*
    This struct cannot have constructor or destructor. It must be POD because it is
    allocated using VmaPoolAllocator.
    */

    void Ctor(uint32_t currentFrameIndex, bool userDataString)
    {
        m_Alignment = 1;
        m_Size = 0;
        m_pUserData = VMA_NULL;
        m_LastUseFrameIndex = currentFrameIndex;
        m_Type = (uint8_t)ALLOCATION_TYPE_NONE;
        m_SuballocationType = (uint8_t)VMA_SUBALLOCATION_TYPE_UNKNOWN;
        m_MapCount = 0;
        m_Flags = userDataString ? (uint8_t)FLAG_USER_DATA_STRING : 0;

#if VMA_STATS_STRING_ENABLED
        m_CreationFrameIndex = currentFrameIndex;
        m_BufferImageUsage = 0;
#endif
    }

    void Dtor()
    {
        VMA_ASSERT((m_MapCount & ~MAP_COUNT_FLAG_PERSISTENT_MAP) == 0 && "Allocation was not unmapped before destruction.");

        // Check if owned string was freed.
        VMA_ASSERT(m_pUserData == VMA_NULL);
    }

    void InitBlockAllocation(
        VmaDeviceMemoryBlock* block,
        VkDeviceSize offset,
        VkDeviceSize alignment,
        VkDeviceSize size,
        VmaSuballocationType suballocationType,
        bool mapped,
        bool canBecomeLost)
    {
        VMA_ASSERT(m_Type == ALLOCATION_TYPE_NONE);
        VMA_ASSERT(block != VMA_NULL);
        m_Type = (uint8_t)ALLOCATION_TYPE_BLOCK;
        m_Alignment = alignment;
        m_Size = size;
        m_MapCount = mapped ? MAP_COUNT_FLAG_PERSISTENT_MAP : 0;
        m_SuballocationType = (uint8_t)suballocationType;
        m_BlockAllocation.m_Block = block;
        m_BlockAllocation.m_Offset = offset;
        m_BlockAllocation.m_CanBecomeLost = canBecomeLost;
    }

    void InitLost()
    {
        VMA_ASSERT(m_Type == ALLOCATION_TYPE_NONE);
        VMA_ASSERT(m_LastUseFrameIndex.load() == VMA_FRAME_INDEX_LOST);
        m_Type = (uint8_t)ALLOCATION_TYPE_BLOCK;
        m_BlockAllocation.m_Block = VMA_NULL;
        m_BlockAllocation.m_Offset = 0;
        m_BlockAllocation.m_CanBecomeLost = true;
    }

    void ChangeBlockAllocation(
        VmaAllocator hAllocator,
        VmaDeviceMemoryBlock* block,
        VkDeviceSize offset); 

    void ChangeSize(VkDeviceSize newSize);
    void ChangeOffset(VkDeviceSize newOffset);

    // pMappedData not null means allocation is created with MAPPED flag.
    void InitDedicatedAllocation(
        uint32_t memoryTypeIndex,
        VkDeviceMemory hMemory,
        VmaSuballocationType suballocationType,
        void* pMappedData,
        VkDeviceSize size)
    {
        VMA_ASSERT(m_Type == ALLOCATION_TYPE_NONE);
        VMA_ASSERT(hMemory != VK_NULL_HANDLE);
        m_Type = (uint8_t)ALLOCATION_TYPE_DEDICATED;
        m_Alignment = 0;
        m_Size = size;
        m_SuballocationType = (uint8_t)suballocationType;
        m_MapCount = (pMappedData != VMA_NULL) ? MAP_COUNT_FLAG_PERSISTENT_MAP : 0;
        m_DedicatedAllocation.m_MemoryTypeIndex = memoryTypeIndex;
        m_DedicatedAllocation.m_hMemory = hMemory;
        m_DedicatedAllocation.m_pMappedData = pMappedData;
    }

    ALLOCATION_TYPE GetType() const { return (ALLOCATION_TYPE)m_Type; }
    VkDeviceSize GetAlignment() const { return m_Alignment; }
    VkDeviceSize GetSize() const { return m_Size; }
    bool IsUserDataString() const { return (m_Flags & FLAG_USER_DATA_STRING) != 0; }
    void* GetUserData() const { return m_pUserData; }
    void SetUserData(VmaAllocator hAllocator, void* pUserData);
    VmaSuballocationType GetSuballocationType() const { return (VmaSuballocationType)m_SuballocationType; }

    VmaDeviceMemoryBlock* GetBlock() const
    {
        VMA_ASSERT(m_Type == ALLOCATION_TYPE_BLOCK);
        return m_BlockAllocation.m_Block;
    }
    VkDeviceSize GetOffset() const;
    VkDeviceMemory GetMemory() const;
    uint32_t GetMemoryTypeIndex() const;
    bool IsPersistentMap() const { return (m_MapCount & MAP_COUNT_FLAG_PERSISTENT_MAP) != 0; }
    void* GetMappedData() const;
    bool CanBecomeLost() const;
    
    uint32_t GetLastUseFrameIndex() const
    {
        return m_LastUseFrameIndex.load();
    }
    bool CompareExchangeLastUseFrameIndex(uint32_t& expected, uint32_t desired)
    {
        return m_LastUseFrameIndex.compare_exchange_weak(expected, desired);
    }
    /*
    - If hAllocation.LastUseFrameIndex + frameInUseCount < allocator.CurrentFrameIndex,
      makes it lost by setting LastUseFrameIndex = VMA_FRAME_INDEX_LOST and returns true.
    - Else, returns false.
    
    If hAllocation is already lost, assert - you should not call it then.
    If hAllocation was not created with CAN_BECOME_LOST_BIT, assert.
    */
    bool MakeLost(uint32_t currentFrameIndex, uint32_t frameInUseCount);

    void DedicatedAllocCalcStatsInfo(VmaStatInfo& outInfo)
    {
        VMA_ASSERT(m_Type == ALLOCATION_TYPE_DEDICATED);
        outInfo.blockCount = 1;
        outInfo.allocationCount = 1;
        outInfo.unusedRangeCount = 0;
        outInfo.usedBytes = m_Size;
        outInfo.unusedBytes = 0;
        outInfo.allocationSizeMin = outInfo.allocationSizeMax = m_Size;
        outInfo.unusedRangeSizeMin = UINT64_MAX;
        outInfo.unusedRangeSizeMax = 0;
    }

    void BlockAllocMap();
    void BlockAllocUnmap();
    VkResult DedicatedAllocMap(VmaAllocator hAllocator, void** ppData);
    void DedicatedAllocUnmap(VmaAllocator hAllocator);

#if VMA_STATS_STRING_ENABLED
    uint32_t GetCreationFrameIndex() const { return m_CreationFrameIndex; }
    uint32_t GetBufferImageUsage() const { return m_BufferImageUsage; }

    void InitBufferImageUsage(uint32_t bufferImageUsage)
    {
        VMA_ASSERT(m_BufferImageUsage == 0);
        m_BufferImageUsage = bufferImageUsage;
    }

    void PrintParameters(class VmaJsonWriter& json) const;
#endif

private:
    VkDeviceSize m_Alignment;
    VkDeviceSize m_Size;
    void* m_pUserData;
    VMA_ATOMIC_UINT32 m_LastUseFrameIndex;
    uint8_t m_Type; // ALLOCATION_TYPE
    uint8_t m_SuballocationType; // VmaSuballocationType
    // Bit 0x80 is set when allocation was created with VMA_ALLOCATION_CREATE_MAPPED_BIT.
    // Bits with mask 0x7F are reference counter for vmaMapMemory()/vmaUnmapMemory().
    uint8_t m_MapCount;
    uint8_t m_Flags; // enum FLAGS

    // Allocation out of VmaDeviceMemoryBlock.
    struct BlockAllocation
    {
        VmaDeviceMemoryBlock* m_Block;
        VkDeviceSize m_Offset;
        bool m_CanBecomeLost;
    };

    // Allocation for an object that has its own private VkDeviceMemory.
    struct DedicatedAllocation
    {
        uint32_t m_MemoryTypeIndex;
        VkDeviceMemory m_hMemory;
        void* m_pMappedData; // Not null means memory is mapped.
    };

    union
    {
        // Allocation out of VmaDeviceMemoryBlock.
        BlockAllocation m_BlockAllocation;
        // Allocation for an object that has its own private VkDeviceMemory.
        DedicatedAllocation m_DedicatedAllocation;
    };

#if VMA_STATS_STRING_ENABLED
    uint32_t m_CreationFrameIndex;
    uint32_t m_BufferImageUsage; // 0 if unknown.
#endif

    void FreeUserDataString(VmaAllocator hAllocator);
};

/*
Represents a region of VmaDeviceMemoryBlock that is either assigned and returned as
allocated memory block or free.
*/
struct VmaSuballocation
{
    VkDeviceSize offset;
    VkDeviceSize size;
    VmaAllocation hAllocation;
    VmaSuballocationType type;
};

// Comparator for offsets.
struct VmaSuballocationOffsetLess
{
    bool operator()(const VmaSuballocation& lhs, const VmaSuballocation& rhs) const
    {
        return lhs.offset < rhs.offset;
    }
};
struct VmaSuballocationOffsetGreater
{
    bool operator()(const VmaSuballocation& lhs, const VmaSuballocation& rhs) const
    {
        return lhs.offset > rhs.offset;
    }
};

typedef VmaList< VmaSuballocation, VmaStlAllocator<VmaSuballocation> > VmaSuballocationList;

// Cost of one additional allocation lost, as equivalent in bytes.
static const VkDeviceSize VMA_LOST_ALLOCATION_COST = 1048576;

enum class VmaAllocationRequestType
{
    Normal,
    // Used by "Linear" algorithm.
    UpperAddress,
    EndOf1st,
    EndOf2nd,
};

/*
Parameters of planned allocation inside a VmaDeviceMemoryBlock.

If canMakeOtherLost was false:
- item points to a FREE suballocation.
- itemsToMakeLostCount is 0.

If canMakeOtherLost was true:
- item points to first of sequence of suballocations, which are either FREE,
  or point to VmaAllocations that can become lost.
- itemsToMakeLostCount is the number of VmaAllocations that need to be made lost for
  the requested allocation to succeed.
*/
struct VmaAllocationRequest
{
    VkDeviceSize offset;
    VkDeviceSize sumFreeSize; // Sum size of free items that overlap with proposed allocation.
    VkDeviceSize sumItemSize; // Sum size of items to make lost that overlap with proposed allocation.
    VmaSuballocationList::iterator item;
    size_t itemsToMakeLostCount;
    void* customData;
    VmaAllocationRequestType type;

    VkDeviceSize CalcCost() const
    {
        return sumItemSize + itemsToMakeLostCount * VMA_LOST_ALLOCATION_COST;
    }
};

/*
Data structure used for bookkeeping of allocations and unused ranges of memory
in a single VkDeviceMemory block.
*/
class VmaBlockMetadata
{
public:
    VmaBlockMetadata(VmaAllocator hAllocator);
    virtual ~VmaBlockMetadata() { }
    virtual void Init(VkDeviceSize size) { m_Size = size; }

    // Validates all data structures inside this object. If not valid, returns false.
    virtual bool Validate() const = 0;
    VkDeviceSize GetSize() const { return m_Size; }
    virtual size_t GetAllocationCount() const = 0;
    virtual VkDeviceSize GetSumFreeSize() const = 0;
    virtual VkDeviceSize GetUnusedRangeSizeMax() const = 0;
    // Returns true if this block is empty - contains only single free suballocation.
    virtual bool IsEmpty() const = 0;

    virtual void CalcAllocationStatInfo(VmaStatInfo& outInfo) const = 0;
    // Shouldn't modify blockCount.
    virtual void AddPoolStats(VmaPoolStats& inoutStats) const = 0;

#if VMA_STATS_STRING_ENABLED
    virtual void PrintDetailedMap(class VmaJsonWriter& json) const = 0;
#endif

    // Tries to find a place for suballocation with given parameters inside this block.
    // If succeeded, fills pAllocationRequest and returns true.
    // If failed, returns false.
    virtual bool CreateAllocationRequest(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VkDeviceSize bufferImageGranularity,
        VkDeviceSize allocSize,
        VkDeviceSize allocAlignment,
        bool upperAddress,
        VmaSuballocationType allocType,
        bool canMakeOtherLost,
        // Always one of VMA_ALLOCATION_CREATE_STRATEGY_* or VMA_ALLOCATION_INTERNAL_STRATEGY_* flags.
        uint32_t strategy,
        VmaAllocationRequest* pAllocationRequest) = 0;

    virtual bool MakeRequestedAllocationsLost(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VmaAllocationRequest* pAllocationRequest) = 0;

    virtual uint32_t MakeAllocationsLost(uint32_t currentFrameIndex, uint32_t frameInUseCount) = 0;

    virtual VkResult CheckCorruption(const void* pBlockData) = 0;

    // Makes actual allocation based on request. Request must already be checked and valid.
    virtual void Alloc(
        const VmaAllocationRequest& request,
        VmaSuballocationType type,
        VkDeviceSize allocSize,
        VmaAllocation hAllocation) = 0;

    // Frees suballocation assigned to given memory region.
    virtual void Free(const VmaAllocation allocation) = 0;
    virtual void FreeAtOffset(VkDeviceSize offset) = 0;

    // Tries to resize (grow or shrink) space for given allocation, in place.
    virtual bool ResizeAllocation(const VmaAllocation alloc, VkDeviceSize newSize) { return false; }

protected:
    const VkAllocationCallbacks* GetAllocationCallbacks() const { return m_pAllocationCallbacks; }

#if VMA_STATS_STRING_ENABLED
    void PrintDetailedMap_Begin(class VmaJsonWriter& json,
        VkDeviceSize unusedBytes,
        size_t allocationCount,
        size_t unusedRangeCount) const;
    void PrintDetailedMap_Allocation(class VmaJsonWriter& json,
        VkDeviceSize offset,
        VmaAllocation hAllocation) const;
    void PrintDetailedMap_UnusedRange(class VmaJsonWriter& json,
        VkDeviceSize offset,
        VkDeviceSize size) const;
    void PrintDetailedMap_End(class VmaJsonWriter& json) const;
#endif

private:
    VkDeviceSize m_Size;
    const VkAllocationCallbacks* m_pAllocationCallbacks;
};

#define VMA_VALIDATE(cond) do { if(!(cond)) { \
        VMA_ASSERT(0 && "Validation failed: " #cond); \
        return false; \
    } } while(false)

class VmaBlockMetadata_Generic : public VmaBlockMetadata
{
    VMA_CLASS_NO_COPY(VmaBlockMetadata_Generic)
public:
    VmaBlockMetadata_Generic(VmaAllocator hAllocator);
    virtual ~VmaBlockMetadata_Generic();
    virtual void Init(VkDeviceSize size);

    virtual bool Validate() const;
    virtual size_t GetAllocationCount() const { return m_Suballocations.size() - m_FreeCount; }
    virtual VkDeviceSize GetSumFreeSize() const { return m_SumFreeSize; }
    virtual VkDeviceSize GetUnusedRangeSizeMax() const;
    virtual bool IsEmpty() const;

    virtual void CalcAllocationStatInfo(VmaStatInfo& outInfo) const;
    virtual void AddPoolStats(VmaPoolStats& inoutStats) const;

#if VMA_STATS_STRING_ENABLED
    virtual void PrintDetailedMap(class VmaJsonWriter& json) const;
#endif

    virtual bool CreateAllocationRequest(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VkDeviceSize bufferImageGranularity,
        VkDeviceSize allocSize,
        VkDeviceSize allocAlignment,
        bool upperAddress,
        VmaSuballocationType allocType,
        bool canMakeOtherLost,
        uint32_t strategy,
        VmaAllocationRequest* pAllocationRequest);

    virtual bool MakeRequestedAllocationsLost(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VmaAllocationRequest* pAllocationRequest);

    virtual uint32_t MakeAllocationsLost(uint32_t currentFrameIndex, uint32_t frameInUseCount);

    virtual VkResult CheckCorruption(const void* pBlockData);

    virtual void Alloc(
        const VmaAllocationRequest& request,
        VmaSuballocationType type,
        VkDeviceSize allocSize,
        VmaAllocation hAllocation);

    virtual void Free(const VmaAllocation allocation);
    virtual void FreeAtOffset(VkDeviceSize offset);

    virtual bool ResizeAllocation(const VmaAllocation alloc, VkDeviceSize newSize);

    // For defragmentation
    
    bool IsBufferImageGranularityConflictPossible(
        VkDeviceSize bufferImageGranularity,
        VmaSuballocationType& inOutPrevSuballocType) const;

private:
    friend class VmaDefragmentationAlgorithm_Generic;
    friend class VmaDefragmentationAlgorithm_Fast;

    uint32_t m_FreeCount;
    VkDeviceSize m_SumFreeSize;
    VmaSuballocationList m_Suballocations;
    // Suballocations that are free and have size greater than certain threshold.
    // Sorted by size, ascending.
    VmaVector< VmaSuballocationList::iterator, VmaStlAllocator< VmaSuballocationList::iterator > > m_FreeSuballocationsBySize;

    bool ValidateFreeSuballocationList() const;

    // Checks if requested suballocation with given parameters can be placed in given pFreeSuballocItem.
    // If yes, fills pOffset and returns true. If no, returns false.
    bool CheckAllocation(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VkDeviceSize bufferImageGranularity,
        VkDeviceSize allocSize,
        VkDeviceSize allocAlignment,
        VmaSuballocationType allocType,
        VmaSuballocationList::const_iterator suballocItem,
        bool canMakeOtherLost,
        VkDeviceSize* pOffset,
        size_t* itemsToMakeLostCount,
        VkDeviceSize* pSumFreeSize,
        VkDeviceSize* pSumItemSize) const;
    // Given free suballocation, it merges it with following one, which must also be free.
    void MergeFreeWithNext(VmaSuballocationList::iterator item);
    // Releases given suballocation, making it free.
    // Merges it with adjacent free suballocations if applicable.
    // Returns iterator to new free suballocation at this place.
    VmaSuballocationList::iterator FreeSuballocation(VmaSuballocationList::iterator suballocItem);
    // Given free suballocation, it inserts it into sorted list of
    // m_FreeSuballocationsBySize if it's suitable.
    void RegisterFreeSuballocation(VmaSuballocationList::iterator item);
    // Given free suballocation, it removes it from sorted list of
    // m_FreeSuballocationsBySize if it's suitable.
    void UnregisterFreeSuballocation(VmaSuballocationList::iterator item);
};

/*
Allocations and their references in internal data structure look like this:

if(m_2ndVectorMode == SECOND_VECTOR_EMPTY):

        0 +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount]
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount + 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  1st[1st.size() - 1]
          +-------+
          |       |
          |       |
          |       |
GetSize() +-------+

if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER):

        0 +-------+
          | Alloc |  2nd[0]
          +-------+
          | Alloc |  2nd[1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  2nd[2nd.size() - 1]
          +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount]
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount + 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  1st[1st.size() - 1]
          +-------+
          |       |
GetSize() +-------+

if(m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK):

        0 +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount]
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount + 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  1st[1st.size() - 1]
          +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  2nd[2nd.size() - 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  2nd[1]
          +-------+
          | Alloc |  2nd[0]
GetSize() +-------+

*/
class VmaBlockMetadata_Linear : public VmaBlockMetadata
{
    VMA_CLASS_NO_COPY(VmaBlockMetadata_Linear)
public:
    VmaBlockMetadata_Linear(VmaAllocator hAllocator);
    virtual ~VmaBlockMetadata_Linear();
    virtual void Init(VkDeviceSize size);

    virtual bool Validate() const;
    virtual size_t GetAllocationCount() const;
    virtual VkDeviceSize GetSumFreeSize() const { return m_SumFreeSize; }
    virtual VkDeviceSize GetUnusedRangeSizeMax() const;
    virtual bool IsEmpty() const { return GetAllocationCount() == 0; }

    virtual void CalcAllocationStatInfo(VmaStatInfo& outInfo) const;
    virtual void AddPoolStats(VmaPoolStats& inoutStats) const;

#if VMA_STATS_STRING_ENABLED
    virtual void PrintDetailedMap(class VmaJsonWriter& json) const;
#endif

    virtual bool CreateAllocationRequest(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VkDeviceSize bufferImageGranularity,
        VkDeviceSize allocSize,
        VkDeviceSize allocAlignment,
        bool upperAddress,
        VmaSuballocationType allocType,
        bool canMakeOtherLost,
        uint32_t strategy,
        VmaAllocationRequest* pAllocationRequest);

    virtual bool MakeRequestedAllocationsLost(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VmaAllocationRequest* pAllocationRequest);

    virtual uint32_t MakeAllocationsLost(uint32_t currentFrameIndex, uint32_t frameInUseCount);

    virtual VkResult CheckCorruption(const void* pBlockData);

    virtual void Alloc(
        const VmaAllocationRequest& request,
        VmaSuballocationType type,
        VkDeviceSize allocSize,
        VmaAllocation hAllocation);

    virtual void Free(const VmaAllocation allocation);
    virtual void FreeAtOffset(VkDeviceSize offset);

private:
    /*
    There are two suballocation vectors, used in ping-pong way.
    The one with index m_1stVectorIndex is called 1st.
    The one with index (m_1stVectorIndex ^ 1) is called 2nd.
    2nd can be non-empty only when 1st is not empty.
    When 2nd is not empty, m_2ndVectorMode indicates its mode of operation.
    */
    typedef VmaVector< VmaSuballocation, VmaStlAllocator<VmaSuballocation> > SuballocationVectorType;

    enum SECOND_VECTOR_MODE
    {
        SECOND_VECTOR_EMPTY,
        /*
        Suballocations in 2nd vector are created later than the ones in 1st, but they
        all have smaller offset.
        */
        SECOND_VECTOR_RING_BUFFER,
        /*
        Suballocations in 2nd vector are upper side of double stack.
        They all have offsets higher than those in 1st vector.
        Top of this stack means smaller offsets, but higher indices in this vector.
        */
        SECOND_VECTOR_DOUBLE_STACK,
    };

    VkDeviceSize m_SumFreeSize;
    SuballocationVectorType m_Suballocations0, m_Suballocations1;
    uint32_t m_1stVectorIndex;
    SECOND_VECTOR_MODE m_2ndVectorMode;

    SuballocationVectorType& AccessSuballocations1st() { return m_1stVectorIndex ? m_Suballocations1 : m_Suballocations0; }
    SuballocationVectorType& AccessSuballocations2nd() { return m_1stVectorIndex ? m_Suballocations0 : m_Suballocations1; }
    const SuballocationVectorType& AccessSuballocations1st() const { return m_1stVectorIndex ? m_Suballocations1 : m_Suballocations0; }
    const SuballocationVectorType& AccessSuballocations2nd() const { return m_1stVectorIndex ? m_Suballocations0 : m_Suballocations1; }
    
    // Number of items in 1st vector with hAllocation = null at the beginning.
    size_t m_1stNullItemsBeginCount;
    // Number of other items in 1st vector with hAllocation = null somewhere in the middle.
    size_t m_1stNullItemsMiddleCount;
    // Number of items in 2nd vector with hAllocation = null.
    size_t m_2ndNullItemsCount;

    bool ShouldCompact1st() const;
    void CleanupAfterFree();

    bool CreateAllocationRequest_LowerAddress(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VkDeviceSize bufferImageGranularity,
        VkDeviceSize allocSize,
        VkDeviceSize allocAlignment,
        VmaSuballocationType allocType,
        bool canMakeOtherLost,
        uint32_t strategy,
        VmaAllocationRequest* pAllocationRequest);
    bool CreateAllocationRequest_UpperAddress(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VkDeviceSize bufferImageGranularity,
        VkDeviceSize allocSize,
        VkDeviceSize allocAlignment,
        VmaSuballocationType allocType,
        bool canMakeOtherLost,
        uint32_t strategy,
        VmaAllocationRequest* pAllocationRequest);
};

/*
- GetSize() is the original size of allocated memory block.
- m_UsableSize is this size aligned down to a power of two.
  All allocations and calculations happen relative to m_UsableSize.
- GetUnusableSize() is the difference between them.
  It is repoted as separate, unused range, not available for allocations.

Node at level 0 has size = m_UsableSize.
Each next level contains nodes with size 2 times smaller than current level.
m_LevelCount is the maximum number of levels to use in the current object.
*/
class VmaBlockMetadata_Buddy : public VmaBlockMetadata
{
    VMA_CLASS_NO_COPY(VmaBlockMetadata_Buddy)
public:
    VmaBlockMetadata_Buddy(VmaAllocator hAllocator);
    virtual ~VmaBlockMetadata_Buddy();
    virtual void Init(VkDeviceSize size);

    virtual bool Validate() const;
    virtual size_t GetAllocationCount() const { return m_AllocationCount; }
    virtual VkDeviceSize GetSumFreeSize() const { return m_SumFreeSize + GetUnusableSize(); }
    virtual VkDeviceSize GetUnusedRangeSizeMax() const;
    virtual bool IsEmpty() const { return m_Root->type == Node::TYPE_FREE; }

    virtual void CalcAllocationStatInfo(VmaStatInfo& outInfo) const;
    virtual void AddPoolStats(VmaPoolStats& inoutStats) const;

#if VMA_STATS_STRING_ENABLED
    virtual void PrintDetailedMap(class VmaJsonWriter& json) const;
#endif

    virtual bool CreateAllocationRequest(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VkDeviceSize bufferImageGranularity,
        VkDeviceSize allocSize,
        VkDeviceSize allocAlignment,
        bool upperAddress,
        VmaSuballocationType allocType,
        bool canMakeOtherLost,
        uint32_t strategy,
        VmaAllocationRequest* pAllocationRequest);

    virtual bool MakeRequestedAllocationsLost(
        uint32_t currentFrameIndex,
        uint32_t frameInUseCount,
        VmaAllocationRequest* pAllocationRequest);

    virtual uint32_t MakeAllocationsLost(uint32_t currentFrameIndex, uint32_t frameInUseCount);

    virtual VkResult CheckCorruption(const void* pBlockData) { return VK_ERROR_FEATURE_NOT_PRESENT; }

    virtual void Alloc(
        const VmaAllocationRequest& request,
        VmaSuballocationType type,
        VkDeviceSize allocSize,
        VmaAllocation hAllocation);

    virtual void Free(const VmaAllocation allocation) { FreeAtOffset(allocation, allocation->GetOffset()); }
    virtual void FreeAtOffset(VkDeviceSize offset) { FreeAtOffset(VMA_NULL, offset); }

private:
    static const VkDeviceSize MIN_NODE_SIZE = 32;
    static const size_t MAX_LEVELS = 30;

    struct ValidationContext
    {
        size_t calculatedAllocationCount;
        size_t calculatedFreeCount;
        VkDeviceSize calculatedSumFreeSize;

        ValidationContext() :
            calculatedAllocationCount(0),
            calculatedFreeCount(0),
            calculatedSumFreeSize(0) { }
    };

    struct Node
    {
        VkDeviceSize offset;
        enum TYPE
        {
            TYPE_FREE,
            TYPE_ALLOCATION,
            TYPE_SPLIT,
            TYPE_COUNT
        } type;
        Node* parent;
        Node* buddy;

        union
        {
            struct
            {
                Node* prev;
                Node* next;
            } free;
            struct
            {
                VmaAllocation alloc;
            } allocation;
            struct
            {
                Node* leftChild;
            } split;
        };
    };

    // Size of the memory block aligned down to a power of two.
    VkDeviceSize m_UsableSize;
    uint32_t m_LevelCount;

    Node* m_Root;
    struct {
        Node* front;
        Node* back;
    } m_FreeList[MAX_LEVELS];
    // Number of nodes in the tree with type == TYPE_ALLOCATION.
    size_t m_AllocationCount;
    // Number of nodes in the tree with type == TYPE_FREE.
    size_t m_FreeCount;
    // This includes space wasted due to internal fragmentation. Doesn't include unusable size.
    VkDeviceSize m_SumFreeSize;

    VkDeviceSize GetUnusableSize() const { return GetSize() - m_UsableSize; }
    void DeleteNode(Node* node);
    bool ValidateNode(ValidationContext& ctx, const Node* parent, const Node* curr, uint32_t level, VkDeviceSize levelNodeSize) const;
    uint32_t AllocSizeToLevel(VkDeviceSize allocSize) const;
    inline VkDeviceSize LevelToNodeSize(uint32_t level) const { return m_UsableSize >> level; }
    // Alloc passed just for validation. Can be null.
    void FreeAtOffset(VmaAllocation alloc, VkDeviceSize offset);
    void CalcAllocationStatInfoNode(VmaStatInfo& outInfo, const Node* node, VkDeviceSize levelNodeSize) const;
    // Adds node to the front of FreeList at given level.
    // node->type must be FREE.
    // node->free.prev, next can be undefined.
    void AddToFreeListFront(uint32_t level, Node* node);
    // Removes node from FreeList at given level.
    // node->type must be FREE.
    // node->free.prev, next stay untouched.
    void RemoveFromFreeList(uint32_t level, Node* node);

#if VMA_STATS_STRING_ENABLED
    void PrintDetailedMapNode(class VmaJsonWriter& json, const Node* node, VkDeviceSize levelNodeSize) const;
#endif
};

/*
Represents a single block of device memory (`VkDeviceMemory`) with all the
data about its regions (aka suballocations, #VmaAllocation), assigned and free.

Thread-safety: This class must be externally synchronized.
*/
class VmaDeviceMemoryBlock
{
    VMA_CLASS_NO_COPY(VmaDeviceMemoryBlock)
public:
    VmaBlockMetadata* m_pMetadata;

    VmaDeviceMemoryBlock(VmaAllocator hAllocator);

    ~VmaDeviceMemoryBlock()
    {
        VMA_ASSERT(m_MapCount == 0 && "VkDeviceMemory block is being destroyed while it is still mapped.");
        VMA_ASSERT(m_hMemory == VK_NULL_HANDLE);
    }

    // Always call after construction.
    void Init(
        VmaAllocator hAllocator,
        VmaPool hParentPool,
        uint32_t newMemoryTypeIndex,
        VkDeviceMemory newMemory,
        VkDeviceSize newSize,
        uint32_t id,
        uint32_t algorithm);
    // Always call before destruction.
    void Destroy(VmaAllocator allocator);
    
    VmaPool GetParentPool() const { return m_hParentPool; }
    VkDeviceMemory GetDeviceMemory() const { return m_hMemory; }
    uint32_t GetMemoryTypeIndex() const { return m_MemoryTypeIndex; }
    uint32_t GetId() const { return m_Id; }
    void* GetMappedData() const { return m_pMappedData; }

    // Validates all data structures inside this object. If not valid, returns false.
    bool Validate() const;

    VkResult CheckCorruption(VmaAllocator hAllocator);

    // ppData can be null.
    VkResult Map(VmaAllocator hAllocator, uint32_t count, void** ppData);
    void Unmap(VmaAllocator hAllocator, uint32_t count);

    VkResult WriteMagicValueAroundAllocation(VmaAllocator hAllocator, VkDeviceSize allocOffset, VkDeviceSize allocSize);
    VkResult ValidateMagicValueAroundAllocation(VmaAllocator hAllocator, VkDeviceSize allocOffset, VkDeviceSize allocSize);

    VkResult BindBufferMemory(
        const VmaAllocator hAllocator,
        const VmaAllocation hAllocation,
        VkBuffer hBuffer);
    VkResult BindImageMemory(
        const VmaAllocator hAllocator,
        const VmaAllocation hAllocation,
        VkImage hImage);

private:
    VmaPool m_hParentPool; // VK_NULL_HANDLE if not belongs to custom pool.
    uint32_t m_MemoryTypeIndex;
    uint32_t m_Id;
    VkDeviceMemory m_hMemory;

    /*
    Protects access to m_hMemory so it's not used by multiple threads simultaneously, e.g. vkMapMemory, vkBindBufferMemory.
    Also protects m_MapCount, m_pMappedData.
    Allocations, deallocations, any change in m_pMetadata is protected by parent's VmaBlockVector::m_Mutex.
    */
    VMA_MUTEX m_Mutex;
    uint32_t m_MapCount;
    void* m_pMappedData;
};

struct VmaPointerLess
{
    bool operator()(const void* lhs, const void* rhs) const
    {
        return lhs < rhs;
    }
};

struct VmaDefragmentationMove
{
    size_t srcBlockIndex;
    size_t dstBlockIndex;
    VkDeviceSize srcOffset;
    VkDeviceSize dstOffset;
    VkDeviceSize size;
};

class VmaDefragmentationAlgorithm;

/*
Sequence of VmaDeviceMemoryBlock. Represents memory blocks allocated for a specific
Vulkan memory type.

Synchronized internally with a mutex.
*/
struct VmaBlockVector
{
    VMA_CLASS_NO_COPY(VmaBlockVector)
public:
    VmaBlockVector(
        VmaAllocator hAllocator,
        VmaPool hParentPool,
        uint32_t memoryTypeIndex,
        VkDeviceSize preferredBlockSize,
        size_t minBlockCount,
        size_t maxBlockCount,
        VkDeviceSize bufferImageGranularity,
        uint32_t frameInUseCount,
        bool isCustomPool,
        bool explicitBlockSize,
        uint32_t algorithm);
    ~VmaBlockVector();

    VkResult CreateMinBlocks();

    VmaPool GetParentPool() const { return m_hParentPool; }
    uint32_t GetMemoryTypeIndex() const { return m_MemoryTypeIndex; }
    VkDeviceSize GetPreferredBlockSize() const { return m_PreferredBlockSize; }
    VkDeviceSize GetBufferImageGranularity() const { return m_BufferImageGranularity; }
    uint32_t GetFrameInUseCount() const { return m_FrameInUseCount; }
    uint32_t GetAlgorithm() const { return m_Algorithm; }

    void GetPoolStats(VmaPoolStats* pStats);

    bool IsEmpty() const { return m_Blocks.empty(); }
    bool IsCorruptionDetectionEnabled() const;

    VkResult Allocate(
        uint32_t currentFrameIndex,
        VkDeviceSize size,
        VkDeviceSize alignment,
        const VmaAllocationCreateInfo& createInfo,
        VmaSuballocationType suballocType,
        size_t allocationCount,
        VmaAllocation* pAllocations);

    void Free(
        VmaAllocation hAllocation);

    // Adds statistics of this BlockVector to pStats.
    void AddStats(VmaStats* pStats);

#if VMA_STATS_STRING_ENABLED
    void PrintDetailedMap(class VmaJsonWriter& json);
#endif

    void MakePoolAllocationsLost(
        uint32_t currentFrameIndex,
        size_t* pLostAllocationCount);
    VkResult CheckCorruption();

    // Saves results in pCtx->res.
    void Defragment(
        class VmaBlockVectorDefragmentationContext* pCtx,
        VmaDefragmentationStats* pStats,
        VkDeviceSize& maxCpuBytesToMove, uint32_t& maxCpuAllocationsToMove,
        VkDeviceSize& maxGpuBytesToMove, uint32_t& maxGpuAllocationsToMove,
        VkCommandBuffer commandBuffer);
    void DefragmentationEnd(
        class VmaBlockVectorDefragmentationContext* pCtx,
        VmaDefragmentationStats* pStats);

    // To be used only while the m_Mutex is locked. Used during defragmentation.

    size_t GetBlockCount() const { return m_Blocks.size(); }
    VmaDeviceMemoryBlock* GetBlock(size_t index) const { return m_Blocks[index]; }
    size_t CalcAllocationCount() const;
    bool IsBufferImageGranularityConflictPossible() const;

private:
    friend class VmaDefragmentationAlgorithm_Generic;

    const VmaAllocator m_hAllocator;
    const VmaPool m_hParentPool;
    const uint32_t m_MemoryTypeIndex;
    const VkDeviceSize m_PreferredBlockSize;
    const size_t m_MinBlockCount;
    const size_t m_MaxBlockCount;
    const VkDeviceSize m_BufferImageGranularity;
    const uint32_t m_FrameInUseCount;
    const bool m_IsCustomPool;
    const bool m_ExplicitBlockSize;
    const uint32_t m_Algorithm;
    /* There can be at most one allocation that is completely empty - a
    hysteresis to avoid pessimistic case of alternating creation and destruction
    of a VkDeviceMemory. */
    bool m_HasEmptyBlock;
    VMA_RW_MUTEX m_Mutex;
    // Incrementally sorted by sumFreeSize, ascending.
    VmaVector< VmaDeviceMemoryBlock*, VmaStlAllocator<VmaDeviceMemoryBlock*> > m_Blocks;
    uint32_t m_NextBlockId;

    VkDeviceSize CalcMaxBlockSize() const;

    // Finds and removes given block from vector.
    void Remove(VmaDeviceMemoryBlock* pBlock);

    // Performs single step in sorting m_Blocks. They may not be fully sorted
    // after this call.
    void IncrementallySortBlocks();

    VkResult AllocatePage(
        uint32_t currentFrameIndex,
        VkDeviceSize size,
        VkDeviceSize alignment,
        const VmaAllocationCreateInfo& createInfo,
        VmaSuballocationType suballocType,
        VmaAllocation* pAllocation);

    // To be used only without CAN_MAKE_OTHER_LOST flag.
    VkResult AllocateFromBlock(
        VmaDeviceMemoryBlock* pBlock,
        uint32_t currentFrameIndex,
        VkDeviceSize size,
        VkDeviceSize alignment,
        VmaAllocationCreateFlags allocFlags,
        void* pUserData,
        VmaSuballocationType suballocType,
        uint32_t strategy,
        VmaAllocation* pAllocation);

    VkResult CreateBlock(VkDeviceSize blockSize, size_t* pNewBlockIndex);

    // Saves result to pCtx->res.
    void ApplyDefragmentationMovesCpu(
        class VmaBlockVectorDefragmentationContext* pDefragCtx,
        const VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves);
    // Saves result to pCtx->res.
    void ApplyDefragmentationMovesGpu(
        class VmaBlockVectorDefragmentationContext* pDefragCtx,
        const VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
        VkCommandBuffer commandBuffer);

    /*
    Used during defragmentation. pDefragmentationStats is optional. It's in/out
    - updated with new data.
    */
    void FreeEmptyBlocks(VmaDefragmentationStats* pDefragmentationStats);
};

struct VmaPool_T
{
    VMA_CLASS_NO_COPY(VmaPool_T)
public:
    VmaBlockVector m_BlockVector;

    VmaPool_T(
        VmaAllocator hAllocator,
        const VmaPoolCreateInfo& createInfo,
        VkDeviceSize preferredBlockSize);
    ~VmaPool_T();

    uint32_t GetId() const { return m_Id; }
    void SetId(uint32_t id) { VMA_ASSERT(m_Id == 0); m_Id = id; }

#if VMA_STATS_STRING_ENABLED
    //void PrintDetailedMap(class VmaStringBuilder& sb);
#endif

private:
    uint32_t m_Id;
};

/*
Performs defragmentation:

- Updates `pBlockVector->m_pMetadata`.
- Updates allocations by calling ChangeBlockAllocation() or ChangeOffset().
- Does not move actual data, only returns requested moves as `moves`.
*/
class VmaDefragmentationAlgorithm
{
    VMA_CLASS_NO_COPY(VmaDefragmentationAlgorithm)
public:
    VmaDefragmentationAlgorithm(
        VmaAllocator hAllocator,
        VmaBlockVector* pBlockVector,
        uint32_t currentFrameIndex) :
        m_hAllocator(hAllocator),
        m_pBlockVector(pBlockVector),
        m_CurrentFrameIndex(currentFrameIndex)
    {
    }
    virtual ~VmaDefragmentationAlgorithm()
    {
    }

    virtual void AddAllocation(VmaAllocation hAlloc, VkBool32* pChanged) = 0;
    virtual void AddAll() = 0;

    virtual VkResult Defragment(
        VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
        VkDeviceSize maxBytesToMove,
        uint32_t maxAllocationsToMove) = 0;

    virtual VkDeviceSize GetBytesMoved() const = 0;
    virtual uint32_t GetAllocationsMoved() const = 0;

protected:
    VmaAllocator const m_hAllocator;
    VmaBlockVector* const m_pBlockVector;
    const uint32_t m_CurrentFrameIndex;

    struct AllocationInfo
    {
        VmaAllocation m_hAllocation;
        VkBool32* m_pChanged;

        AllocationInfo() :
            m_hAllocation(VK_NULL_HANDLE),
            m_pChanged(VMA_NULL)
        {
        }
        AllocationInfo(VmaAllocation hAlloc, VkBool32* pChanged) :
            m_hAllocation(hAlloc),
            m_pChanged(pChanged)
        {
        }
    };
};

class VmaDefragmentationAlgorithm_Generic : public VmaDefragmentationAlgorithm
{
    VMA_CLASS_NO_COPY(VmaDefragmentationAlgorithm_Generic)
public:
    VmaDefragmentationAlgorithm_Generic(
        VmaAllocator hAllocator,
        VmaBlockVector* pBlockVector,
        uint32_t currentFrameIndex,
        bool overlappingMoveSupported);
    virtual ~VmaDefragmentationAlgorithm_Generic();

    virtual void AddAllocation(VmaAllocation hAlloc, VkBool32* pChanged);
    virtual void AddAll() { m_AllAllocations = true; }

    virtual VkResult Defragment(
        VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
        VkDeviceSize maxBytesToMove,
        uint32_t maxAllocationsToMove);

    virtual VkDeviceSize GetBytesMoved() const { return m_BytesMoved; }
    virtual uint32_t GetAllocationsMoved() const { return m_AllocationsMoved; }

private:
    uint32_t m_AllocationCount;
    bool m_AllAllocations;

    VkDeviceSize m_BytesMoved;
    uint32_t m_AllocationsMoved;

    struct AllocationInfoSizeGreater
    {
        bool operator()(const AllocationInfo& lhs, const AllocationInfo& rhs) const
        {
            return lhs.m_hAllocation->GetSize() > rhs.m_hAllocation->GetSize();
        }
    };

    struct AllocationInfoOffsetGreater
    {
        bool operator()(const AllocationInfo& lhs, const AllocationInfo& rhs) const
        {
            return lhs.m_hAllocation->GetOffset() > rhs.m_hAllocation->GetOffset();
        }
    };

    struct BlockInfo
    {
        size_t m_OriginalBlockIndex;
        VmaDeviceMemoryBlock* m_pBlock;
        bool m_HasNonMovableAllocations;
        VmaVector< AllocationInfo, VmaStlAllocator<AllocationInfo> > m_Allocations;

        BlockInfo(const VkAllocationCallbacks* pAllocationCallbacks) :
            m_OriginalBlockIndex(SIZE_MAX),
            m_pBlock(VMA_NULL),
            m_HasNonMovableAllocations(true),
            m_Allocations(pAllocationCallbacks)
        {
        }

        void CalcHasNonMovableAllocations()
        {
            const size_t blockAllocCount = m_pBlock->m_pMetadata->GetAllocationCount();
            const size_t defragmentAllocCount = m_Allocations.size();
            m_HasNonMovableAllocations = blockAllocCount != defragmentAllocCount;
        }

        void SortAllocationsBySizeDescending()
        {
            VMA_SORT(m_Allocations.begin(), m_Allocations.end(), AllocationInfoSizeGreater());
        }

        void SortAllocationsByOffsetDescending()
        {
            VMA_SORT(m_Allocations.begin(), m_Allocations.end(), AllocationInfoOffsetGreater());
        }
    };

    struct BlockPointerLess
    {
        bool operator()(const BlockInfo* pLhsBlockInfo, const VmaDeviceMemoryBlock* pRhsBlock) const
        {
            return pLhsBlockInfo->m_pBlock < pRhsBlock;
        }
        bool operator()(const BlockInfo* pLhsBlockInfo, const BlockInfo* pRhsBlockInfo) const
        {
            return pLhsBlockInfo->m_pBlock < pRhsBlockInfo->m_pBlock;
        }
    };

    // 1. Blocks with some non-movable allocations go first.
    // 2. Blocks with smaller sumFreeSize go first.
    struct BlockInfoCompareMoveDestination
    {
        bool operator()(const BlockInfo* pLhsBlockInfo, const BlockInfo* pRhsBlockInfo) const
        {
            if(pLhsBlockInfo->m_HasNonMovableAllocations && !pRhsBlockInfo->m_HasNonMovableAllocations)
            {
                return true;
            }
            if(!pLhsBlockInfo->m_HasNonMovableAllocations && pRhsBlockInfo->m_HasNonMovableAllocations)
            {
                return false;
            }
            if(pLhsBlockInfo->m_pBlock->m_pMetadata->GetSumFreeSize() < pRhsBlockInfo->m_pBlock->m_pMetadata->GetSumFreeSize())
            {
                return true;
            }
            return false;
        }
    };

    typedef VmaVector< BlockInfo*, VmaStlAllocator<BlockInfo*> > BlockInfoVector;
    BlockInfoVector m_Blocks;

    VkResult DefragmentRound(
        VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
        VkDeviceSize maxBytesToMove,
        uint32_t maxAllocationsToMove);

    size_t CalcBlocksWithNonMovableCount() const;

    static bool MoveMakesSense(
        size_t dstBlockIndex, VkDeviceSize dstOffset,
        size_t srcBlockIndex, VkDeviceSize srcOffset);
};

class VmaDefragmentationAlgorithm_Fast : public VmaDefragmentationAlgorithm
{
    VMA_CLASS_NO_COPY(VmaDefragmentationAlgorithm_Fast)
public:
    VmaDefragmentationAlgorithm_Fast(
        VmaAllocator hAllocator,
        VmaBlockVector* pBlockVector,
        uint32_t currentFrameIndex,
        bool overlappingMoveSupported);
    virtual ~VmaDefragmentationAlgorithm_Fast();

    virtual void AddAllocation(VmaAllocation hAlloc, VkBool32* pChanged) { ++m_AllocationCount; }
    virtual void AddAll() { m_AllAllocations = true; }

    virtual VkResult Defragment(
        VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
        VkDeviceSize maxBytesToMove,
        uint32_t maxAllocationsToMove);

    virtual VkDeviceSize GetBytesMoved() const { return m_BytesMoved; }
    virtual uint32_t GetAllocationsMoved() const { return m_AllocationsMoved; }

private:
    struct BlockInfo
    {
        size_t origBlockIndex;
    };

    class FreeSpaceDatabase
    {
    public:
        FreeSpaceDatabase()
        {
            FreeSpace s = {};
            s.blockInfoIndex = SIZE_MAX;
            for(size_t i = 0; i < MAX_COUNT; ++i)
            {
                m_FreeSpaces[i] = s;
            }
        }

        void Register(size_t blockInfoIndex, VkDeviceSize offset, VkDeviceSize size)
        {
            if(size < VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER)
            {
                return;
            }

            // Find first invalid or the smallest structure.
            size_t bestIndex = SIZE_MAX;
            for(size_t i = 0; i < MAX_COUNT; ++i)
            {
                // Empty structure.
                if(m_FreeSpaces[i].blockInfoIndex == SIZE_MAX)
                {
                    bestIndex = i;
                    break;
                }
                if(m_FreeSpaces[i].size < size &&
                    (bestIndex == SIZE_MAX || m_FreeSpaces[bestIndex].size > m_FreeSpaces[i].size))
                {
                    bestIndex = i;
                }
            }

            if(bestIndex != SIZE_MAX)
            {
                m_FreeSpaces[bestIndex].blockInfoIndex = blockInfoIndex;
                m_FreeSpaces[bestIndex].offset = offset;
                m_FreeSpaces[bestIndex].size = size;
            }
        }

        bool Fetch(VkDeviceSize alignment, VkDeviceSize size,
            size_t& outBlockInfoIndex, VkDeviceSize& outDstOffset)
        {
            size_t bestIndex = SIZE_MAX;
            VkDeviceSize bestFreeSpaceAfter = 0;
            for(size_t i = 0; i < MAX_COUNT; ++i)
            {
                // Structure is valid.
                if(m_FreeSpaces[i].blockInfoIndex != SIZE_MAX)
                {
                    const VkDeviceSize dstOffset = VmaAlignUp(m_FreeSpaces[i].offset, alignment);
                    // Allocation fits into this structure.
                    if(dstOffset + size <= m_FreeSpaces[i].offset + m_FreeSpaces[i].size)
                    {
                        const VkDeviceSize freeSpaceAfter = (m_FreeSpaces[i].offset + m_FreeSpaces[i].size) -
                            (dstOffset + size);
                        if(bestIndex == SIZE_MAX || freeSpaceAfter > bestFreeSpaceAfter)
                        {
                            bestIndex = i;
                            bestFreeSpaceAfter = freeSpaceAfter;
                        }
                    }
                }
            }
            
            if(bestIndex != SIZE_MAX)
            {
                outBlockInfoIndex = m_FreeSpaces[bestIndex].blockInfoIndex;
                outDstOffset = VmaAlignUp(m_FreeSpaces[bestIndex].offset, alignment);

                if(bestFreeSpaceAfter >= VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER)
                {
                    // Leave this structure for remaining empty space.
                    const VkDeviceSize alignmentPlusSize = (outDstOffset - m_FreeSpaces[bestIndex].offset) + size;
                    m_FreeSpaces[bestIndex].offset += alignmentPlusSize;
                    m_FreeSpaces[bestIndex].size -= alignmentPlusSize;
                }
                else
                {
                    // This structure becomes invalid.
                    m_FreeSpaces[bestIndex].blockInfoIndex = SIZE_MAX;
                }

                return true;
            }

            return false;
        }

    private:
        static const size_t MAX_COUNT = 4;

        struct FreeSpace
        {
            size_t blockInfoIndex; // SIZE_MAX means this structure is invalid.
            VkDeviceSize offset;
            VkDeviceSize size;
        } m_FreeSpaces[MAX_COUNT];
    };

    const bool m_OverlappingMoveSupported;

    uint32_t m_AllocationCount;
    bool m_AllAllocations;

    VkDeviceSize m_BytesMoved;
    uint32_t m_AllocationsMoved;

    VmaVector< BlockInfo, VmaStlAllocator<BlockInfo> > m_BlockInfos;

    void PreprocessMetadata();
    void PostprocessMetadata();
    void InsertSuballoc(VmaBlockMetadata_Generic* pMetadata, const VmaSuballocation& suballoc);
};

struct VmaBlockDefragmentationContext
{
    enum BLOCK_FLAG
    {
        BLOCK_FLAG_USED = 0x00000001,
    };
    uint32_t flags;
    VkBuffer hBuffer;

    VmaBlockDefragmentationContext() :
        flags(0),
        hBuffer(VK_NULL_HANDLE)
    {
    }
};

class VmaBlockVectorDefragmentationContext
{
    VMA_CLASS_NO_COPY(VmaBlockVectorDefragmentationContext)
public:
    VkResult res;
    bool mutexLocked;
    VmaVector< VmaBlockDefragmentationContext, VmaStlAllocator<VmaBlockDefragmentationContext> > blockContexts;

    VmaBlockVectorDefragmentationContext(
        VmaAllocator hAllocator,
        VmaPool hCustomPool, // Optional.
        VmaBlockVector* pBlockVector,
        uint32_t currFrameIndex,
        uint32_t flags);
    ~VmaBlockVectorDefragmentationContext();

    VmaPool GetCustomPool() const { return m_hCustomPool; }
    VmaBlockVector* GetBlockVector() const { return m_pBlockVector; }
    VmaDefragmentationAlgorithm* GetAlgorithm() const { return m_pAlgorithm; }

    void AddAllocation(VmaAllocation hAlloc, VkBool32* pChanged);
    void AddAll() { m_AllAllocations = true; }

    void Begin(bool overlappingMoveSupported);

private:
    const VmaAllocator m_hAllocator;
    // Null if not from custom pool.
    const VmaPool m_hCustomPool;
    // Redundant, for convenience not to fetch from m_hCustomPool->m_BlockVector or m_hAllocator->m_pBlockVectors.
    VmaBlockVector* const m_pBlockVector;
    const uint32_t m_CurrFrameIndex;
    const uint32_t m_AlgorithmFlags;
    // Owner of this object.
    VmaDefragmentationAlgorithm* m_pAlgorithm;

    struct AllocInfo
    {
        VmaAllocation hAlloc;
        VkBool32* pChanged;
    };
    // Used between constructor and Begin.
    VmaVector< AllocInfo, VmaStlAllocator<AllocInfo> > m_Allocations;
    bool m_AllAllocations;
};

struct VmaDefragmentationContext_T
{
private:
    VMA_CLASS_NO_COPY(VmaDefragmentationContext_T)
public:
    VmaDefragmentationContext_T(
        VmaAllocator hAllocator,
        uint32_t currFrameIndex,
        uint32_t flags,
        VmaDefragmentationStats* pStats);
    ~VmaDefragmentationContext_T();

    void AddPools(uint32_t poolCount, VmaPool* pPools);
    void AddAllocations(
        uint32_t allocationCount,
        VmaAllocation* pAllocations,
        VkBool32* pAllocationsChanged);

    /*
    Returns:
    - `VK_SUCCESS` if succeeded and object can be destroyed immediately.
    - `VK_NOT_READY` if succeeded but the object must remain alive until vmaDefragmentationEnd().
    - Negative value if error occured and object can be destroyed immediately.
    */
    VkResult Defragment(
        VkDeviceSize maxCpuBytesToMove, uint32_t maxCpuAllocationsToMove,
        VkDeviceSize maxGpuBytesToMove, uint32_t maxGpuAllocationsToMove,
        VkCommandBuffer commandBuffer, VmaDefragmentationStats* pStats);

private:
    const VmaAllocator m_hAllocator;
    const uint32_t m_CurrFrameIndex;
    const uint32_t m_Flags;
    VmaDefragmentationStats* const m_pStats;
    // Owner of these objects.
    VmaBlockVectorDefragmentationContext* m_DefaultPoolContexts[VK_MAX_MEMORY_TYPES];
    // Owner of these objects.
    VmaVector< VmaBlockVectorDefragmentationContext*, VmaStlAllocator<VmaBlockVectorDefragmentationContext*> > m_CustomPoolContexts;
};

#if VMA_RECORDING_ENABLED

class VmaRecorder
{
public:
    VmaRecorder();
    VkResult Init(const VmaRecordSettings& settings, bool useMutex);
    void WriteConfiguration(
        const VkPhysicalDeviceProperties& devProps,
        const VkPhysicalDeviceMemoryProperties& memProps,
        bool dedicatedAllocationExtensionEnabled);
    ~VmaRecorder();

    void RecordCreateAllocator(uint32_t frameIndex);
    void RecordDestroyAllocator(uint32_t frameIndex);
    void RecordCreatePool(uint32_t frameIndex,
        const VmaPoolCreateInfo& createInfo,
        VmaPool pool);
    void RecordDestroyPool(uint32_t frameIndex, VmaPool pool);
    void RecordAllocateMemory(uint32_t frameIndex,
        const VkMemoryRequirements& vkMemReq,
        const VmaAllocationCreateInfo& createInfo,
        VmaAllocation allocation);
    void RecordAllocateMemoryPages(uint32_t frameIndex,
        const VkMemoryRequirements& vkMemReq,
        const VmaAllocationCreateInfo& createInfo,
        uint64_t allocationCount,
        const VmaAllocation* pAllocations);
    void RecordAllocateMemoryForBuffer(uint32_t frameIndex,
        const VkMemoryRequirements& vkMemReq,
        bool requiresDedicatedAllocation,
        bool prefersDedicatedAllocation,
        const VmaAllocationCreateInfo& createInfo,
        VmaAllocation allocation);
    void RecordAllocateMemoryForImage(uint32_t frameIndex,
        const VkMemoryRequirements& vkMemReq,
        bool requiresDedicatedAllocation,
        bool prefersDedicatedAllocation,
        const VmaAllocationCreateInfo& createInfo,
        VmaAllocation allocation);
    void RecordFreeMemory(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordFreeMemoryPages(uint32_t frameIndex,
        uint64_t allocationCount,
        const VmaAllocation* pAllocations);
    void RecordResizeAllocation(
        uint32_t frameIndex,
        VmaAllocation allocation,
        VkDeviceSize newSize);
    void RecordSetAllocationUserData(uint32_t frameIndex,
        VmaAllocation allocation,
        const void* pUserData);
    void RecordCreateLostAllocation(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordMapMemory(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordUnmapMemory(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordFlushAllocation(uint32_t frameIndex,
        VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size);
    void RecordInvalidateAllocation(uint32_t frameIndex,
        VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size);
    void RecordCreateBuffer(uint32_t frameIndex,
        const VkBufferCreateInfo& bufCreateInfo,
        const VmaAllocationCreateInfo& allocCreateInfo,
        VmaAllocation allocation);
    void RecordCreateImage(uint32_t frameIndex,
        const VkImageCreateInfo& imageCreateInfo,
        const VmaAllocationCreateInfo& allocCreateInfo,
        VmaAllocation allocation);
    void RecordDestroyBuffer(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordDestroyImage(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordTouchAllocation(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordGetAllocationInfo(uint32_t frameIndex,
        VmaAllocation allocation);
    void RecordMakePoolAllocationsLost(uint32_t frameIndex,
        VmaPool pool);
    void RecordDefragmentationBegin(uint32_t frameIndex,
        const VmaDefragmentationInfo2& info,
        VmaDefragmentationContext ctx);
    void RecordDefragmentationEnd(uint32_t frameIndex,
        VmaDefragmentationContext ctx);

private:
    struct CallParams
    {
        uint32_t threadId;
        double time;
    };

    class UserDataString
    {
    public:
        UserDataString(VmaAllocationCreateFlags allocFlags, const void* pUserData);
        const char* GetString() const { return m_Str; }

    private:
        char m_PtrStr[17];
        const char* m_Str;
    };

    bool m_UseMutex;
    VmaRecordFlags m_Flags;
    FILE* m_File;
    VMA_MUTEX m_FileMutex;
    int64_t m_Freq;
    int64_t m_StartCounter;

    void GetBasicParams(CallParams& outParams);

    // T must be a pointer type, e.g. VmaAllocation, VmaPool.
    template<typename T>
    void PrintPointerList(uint64_t count, const T* pItems)
    {
        if(count)
        {
            fprintf(m_File, "%p", pItems[0]);
            for(uint64_t i = 1; i < count; ++i)
            {
                fprintf(m_File, " %p", pItems[i]);
            }
        }
    }

    void PrintPointerList(uint64_t count, const VmaAllocation* pItems);
    void Flush();
};

#endif // #if VMA_RECORDING_ENABLED

/*
Thread-safe wrapper over VmaPoolAllocator free list, for allocation of VmaAllocation_T objects.
*/
class VmaAllocationObjectAllocator
{
    VMA_CLASS_NO_COPY(VmaAllocationObjectAllocator)
public:
    VmaAllocationObjectAllocator(const VkAllocationCallbacks* pAllocationCallbacks);

    VmaAllocation Allocate();
    void Free(VmaAllocation hAlloc);

private:
    VMA_MUTEX m_Mutex;
    VmaPoolAllocator<VmaAllocation_T> m_Allocator;
};

// Main allocator object.
struct VmaAllocator_T
{
    VMA_CLASS_NO_COPY(VmaAllocator_T)
public:
    bool m_UseMutex;
    bool m_UseKhrDedicatedAllocation;
    VkDevice m_hDevice;
    bool m_AllocationCallbacksSpecified;
    VkAllocationCallbacks m_AllocationCallbacks;
    VmaDeviceMemoryCallbacks m_DeviceMemoryCallbacks;
    VmaAllocationObjectAllocator m_AllocationObjectAllocator;
    
    // Number of bytes free out of limit, or VK_WHOLE_SIZE if no limit for that heap.
    VkDeviceSize m_HeapSizeLimit[VK_MAX_MEMORY_HEAPS];
    VMA_MUTEX m_HeapSizeLimitMutex;

    VkPhysicalDeviceProperties m_PhysicalDeviceProperties;
    VkPhysicalDeviceMemoryProperties m_MemProps;

    // Default pools.
    VmaBlockVector* m_pBlockVectors[VK_MAX_MEMORY_TYPES];

    // Each vector is sorted by memory (handle value).
    typedef VmaVector< VmaAllocation, VmaStlAllocator<VmaAllocation> > AllocationVectorType;
    AllocationVectorType* m_pDedicatedAllocations[VK_MAX_MEMORY_TYPES];
    VMA_RW_MUTEX m_DedicatedAllocationsMutex[VK_MAX_MEMORY_TYPES];

    VmaAllocator_T(const VmaAllocatorCreateInfo* pCreateInfo);
    VkResult Init(const VmaAllocatorCreateInfo* pCreateInfo);
    ~VmaAllocator_T();

    const VkAllocationCallbacks* GetAllocationCallbacks() const
    {
        return m_AllocationCallbacksSpecified ? &m_AllocationCallbacks : 0;
    }
    const VmaVulkanFunctions& GetVulkanFunctions() const
    {
        return m_VulkanFunctions;
    }

    VkDeviceSize GetBufferImageGranularity() const
    {
        return VMA_MAX(
            static_cast<VkDeviceSize>(VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY),
            m_PhysicalDeviceProperties.limits.bufferImageGranularity);
    }

    uint32_t GetMemoryHeapCount() const { return m_MemProps.memoryHeapCount; }
    uint32_t GetMemoryTypeCount() const { return m_MemProps.memoryTypeCount; }

    uint32_t MemoryTypeIndexToHeapIndex(uint32_t memTypeIndex) const
    {
        VMA_ASSERT(memTypeIndex < m_MemProps.memoryTypeCount);
        return m_MemProps.memoryTypes[memTypeIndex].heapIndex;
    }
    // True when specific memory type is HOST_VISIBLE but not HOST_COHERENT.
    bool IsMemoryTypeNonCoherent(uint32_t memTypeIndex) const
    {
        return (m_MemProps.memoryTypes[memTypeIndex].propertyFlags & (VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT)) ==
            VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT;
    }
    // Minimum alignment for all allocations in specific memory type.
    VkDeviceSize GetMemoryTypeMinAlignment(uint32_t memTypeIndex) const
    {
        return IsMemoryTypeNonCoherent(memTypeIndex) ?
            VMA_MAX((VkDeviceSize)VMA_DEBUG_ALIGNMENT, m_PhysicalDeviceProperties.limits.nonCoherentAtomSize) :
            (VkDeviceSize)VMA_DEBUG_ALIGNMENT;
    }

    bool IsIntegratedGpu() const
    {
        return m_PhysicalDeviceProperties.deviceType == VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU;
    }

#if VMA_RECORDING_ENABLED
    VmaRecorder* GetRecorder() const { return m_pRecorder; }
#endif

    void GetBufferMemoryRequirements(
        VkBuffer hBuffer,
        VkMemoryRequirements& memReq,
        bool& requiresDedicatedAllocation,
        bool& prefersDedicatedAllocation) const;
    void GetImageMemoryRequirements(
        VkImage hImage,
        VkMemoryRequirements& memReq,
        bool& requiresDedicatedAllocation,
        bool& prefersDedicatedAllocation) const;

    // Main allocation function.
    VkResult AllocateMemory(
        const VkMemoryRequirements& vkMemReq,
        bool requiresDedicatedAllocation,
        bool prefersDedicatedAllocation,
        VkBuffer dedicatedBuffer,
        VkImage dedicatedImage,
        const VmaAllocationCreateInfo& createInfo,
        VmaSuballocationType suballocType,
        size_t allocationCount,
        VmaAllocation* pAllocations);

    // Main deallocation function.
    void FreeMemory(
        size_t allocationCount,
        const VmaAllocation* pAllocations);

    VkResult ResizeAllocation(
        const VmaAllocation alloc,
        VkDeviceSize newSize);

    void CalculateStats(VmaStats* pStats);

#if VMA_STATS_STRING_ENABLED
    void PrintDetailedMap(class VmaJsonWriter& json);
#endif

    VkResult DefragmentationBegin(
        const VmaDefragmentationInfo2& info,
        VmaDefragmentationStats* pStats,
        VmaDefragmentationContext* pContext);
    VkResult DefragmentationEnd(
        VmaDefragmentationContext context);

    void GetAllocationInfo(VmaAllocation hAllocation, VmaAllocationInfo* pAllocationInfo);
    bool TouchAllocation(VmaAllocation hAllocation);

    VkResult CreatePool(const VmaPoolCreateInfo* pCreateInfo, VmaPool* pPool);
    void DestroyPool(VmaPool pool);
    void GetPoolStats(VmaPool pool, VmaPoolStats* pPoolStats);

    void SetCurrentFrameIndex(uint32_t frameIndex);
    uint32_t GetCurrentFrameIndex() const { return m_CurrentFrameIndex.load(); }

    void MakePoolAllocationsLost(
        VmaPool hPool,
        size_t* pLostAllocationCount);
    VkResult CheckPoolCorruption(VmaPool hPool);
    VkResult CheckCorruption(uint32_t memoryTypeBits);

    void CreateLostAllocation(VmaAllocation* pAllocation);

    VkResult AllocateVulkanMemory(const VkMemoryAllocateInfo* pAllocateInfo, VkDeviceMemory* pMemory);
    void FreeVulkanMemory(uint32_t memoryType, VkDeviceSize size, VkDeviceMemory hMemory);

    VkResult Map(VmaAllocation hAllocation, void** ppData);
    void Unmap(VmaAllocation hAllocation);

    VkResult BindBufferMemory(VmaAllocation hAllocation, VkBuffer hBuffer);
    VkResult BindImageMemory(VmaAllocation hAllocation, VkImage hImage);

    void FlushOrInvalidateAllocation(
        VmaAllocation hAllocation,
        VkDeviceSize offset, VkDeviceSize size,
        VMA_CACHE_OPERATION op);

    void FillAllocation(const VmaAllocation hAllocation, uint8_t pattern);

    /*
    Returns bit mask of memory types that can support defragmentation on GPU as
    they support creation of required buffer for copy operations.
    */
    uint32_t GetGpuDefragmentationMemoryTypeBits();

private:
    VkDeviceSize m_PreferredLargeHeapBlockSize;

    VkPhysicalDevice m_PhysicalDevice;
    VMA_ATOMIC_UINT32 m_CurrentFrameIndex;
    VMA_ATOMIC_UINT32 m_GpuDefragmentationMemoryTypeBits; // UINT32_MAX means uninitialized.
    
    VMA_RW_MUTEX m_PoolsMutex;
    // Protected by m_PoolsMutex. Sorted by pointer value.
    VmaVector<VmaPool, VmaStlAllocator<VmaPool> > m_Pools;
    uint32_t m_NextPoolId;

    VmaVulkanFunctions m_VulkanFunctions;

#if VMA_RECORDING_ENABLED
    VmaRecorder* m_pRecorder;
#endif

    void ImportVulkanFunctions(const VmaVulkanFunctions* pVulkanFunctions);

    VkDeviceSize CalcPreferredBlockSize(uint32_t memTypeIndex);

    VkResult AllocateMemoryOfType(
        VkDeviceSize size,
        VkDeviceSize alignment,
        bool dedicatedAllocation,
        VkBuffer dedicatedBuffer,
        VkImage dedicatedImage,
        const VmaAllocationCreateInfo& createInfo,
        uint32_t memTypeIndex,
        VmaSuballocationType suballocType,
        size_t allocationCount,
        VmaAllocation* pAllocations);

    // Helper function only to be used inside AllocateDedicatedMemory.
    VkResult AllocateDedicatedMemoryPage(
        VkDeviceSize size,
        VmaSuballocationType suballocType,
        uint32_t memTypeIndex,
        const VkMemoryAllocateInfo& allocInfo,
        bool map,
        bool isUserDataString,
        void* pUserData,
        VmaAllocation* pAllocation);

    // Allocates and registers new VkDeviceMemory specifically for dedicated allocations.
    VkResult AllocateDedicatedMemory(
        VkDeviceSize size,
        VmaSuballocationType suballocType,
        uint32_t memTypeIndex,
        bool map,
        bool isUserDataString,
        void* pUserData,
        VkBuffer dedicatedBuffer,
        VkImage dedicatedImage,
        size_t allocationCount,
        VmaAllocation* pAllocations);

    // Tries to free pMemory as Dedicated Memory. Returns true if found and freed.
    void FreeDedicatedMemory(VmaAllocation allocation);

    /*
    Calculates and returns bit mask of memory types that can support defragmentation
    on GPU as they support creation of required buffer for copy operations.
    */
    uint32_t CalculateGpuDefragmentationMemoryTypeBits() const;
};

// Memory allocation #2 after VmaAllocator_T definition

static void* VmaMalloc(VmaAllocator hAllocator, size_t size, size_t alignment)
{
    return VmaMalloc(&hAllocator->m_AllocationCallbacks, size, alignment);
}

static void VmaFree(VmaAllocator hAllocator, void* ptr)
{
    VmaFree(&hAllocator->m_AllocationCallbacks, ptr);
}

template<typename T>
static T* VmaAllocate(VmaAllocator hAllocator)
{
    return (T*)VmaMalloc(hAllocator, sizeof(T), VMA_ALIGN_OF(T));
}

template<typename T>
static T* VmaAllocateArray(VmaAllocator hAllocator, size_t count)
{
    return (T*)VmaMalloc(hAllocator, sizeof(T) * count, VMA_ALIGN_OF(T));
}

template<typename T>
static void vma_delete(VmaAllocator hAllocator, T* ptr)
{
    if(ptr != VMA_NULL)
    {
        ptr->~T();
        VmaFree(hAllocator, ptr);
    }
}

template<typename T>
static void vma_delete_array(VmaAllocator hAllocator, T* ptr, size_t count)
{
    if(ptr != VMA_NULL)
    {
        for(size_t i = count; i--; )
            ptr[i].~T();
        VmaFree(hAllocator, ptr);
    }
}

// VmaStringBuilder

#if VMA_STATS_STRING_ENABLED

class VmaStringBuilder
{
public:
    VmaStringBuilder(VmaAllocator alloc) : m_Data(VmaStlAllocator<char>(alloc->GetAllocationCallbacks())) { }
    size_t GetLength() const { return m_Data.size(); }
    const char* GetData() const { return m_Data.data(); }

    void Add(char ch) { m_Data.push_back(ch); }
    void Add(const char* pStr);
    void AddNewLine() { Add('\n'); }
    void AddNumber(uint32_t num);
    void AddNumber(uint64_t num);
    void AddPointer(const void* ptr);

private:
    VmaVector< char, VmaStlAllocator<char> > m_Data;
};

void VmaStringBuilder::Add(const char* pStr)
{
    const size_t strLen = strlen(pStr);
    if(strLen > 0)
    {
        const size_t oldCount = m_Data.size();
        m_Data.resize(oldCount + strLen);
        memcpy(m_Data.data() + oldCount, pStr, strLen);
    }
}

void VmaStringBuilder::AddNumber(uint32_t num)
{
    char buf[11];
    VmaUint32ToStr(buf, sizeof(buf), num);
    Add(buf);
}

void VmaStringBuilder::AddNumber(uint64_t num)
{
    char buf[21];
    VmaUint64ToStr(buf, sizeof(buf), num);
    Add(buf);
}

void VmaStringBuilder::AddPointer(const void* ptr)
{
    char buf[21];
    VmaPtrToStr(buf, sizeof(buf), ptr);
    Add(buf);
}

#endif // #if VMA_STATS_STRING_ENABLED

// VmaJsonWriter

#if VMA_STATS_STRING_ENABLED

class VmaJsonWriter
{
    VMA_CLASS_NO_COPY(VmaJsonWriter)
public:
    VmaJsonWriter(const VkAllocationCallbacks* pAllocationCallbacks, VmaStringBuilder& sb);
    ~VmaJsonWriter();

    void BeginObject(bool singleLine = false);
    void EndObject();
    
    void BeginArray(bool singleLine = false);
    void EndArray();
    
    void WriteString(const char* pStr);
    void BeginString(const char* pStr = VMA_NULL);
    void ContinueString(const char* pStr);
    void ContinueString(uint32_t n);
    void ContinueString(uint64_t n);
    void ContinueString_Pointer(const void* ptr);
    void EndString(const char* pStr = VMA_NULL);
    
    void WriteNumber(uint32_t n);
    void WriteNumber(uint64_t n);
    void WriteBool(bool b);
    void WriteNull();

private:
    static const char* const INDENT;

    enum COLLECTION_TYPE
    {
        COLLECTION_TYPE_OBJECT,
        COLLECTION_TYPE_ARRAY,
    };
    struct StackItem
    {
        COLLECTION_TYPE type;
        uint32_t valueCount;
        bool singleLineMode;
    };

    VmaStringBuilder& m_SB;
    VmaVector< StackItem, VmaStlAllocator<StackItem> > m_Stack;
    bool m_InsideString;

    void BeginValue(bool isString);
    void WriteIndent(bool oneLess = false);
};

const char* const VmaJsonWriter::INDENT = "  ";

VmaJsonWriter::VmaJsonWriter(const VkAllocationCallbacks* pAllocationCallbacks, VmaStringBuilder& sb) :
    m_SB(sb),
    m_Stack(VmaStlAllocator<StackItem>(pAllocationCallbacks)),
    m_InsideString(false)
{
}

VmaJsonWriter::~VmaJsonWriter()
{
    VMA_ASSERT(!m_InsideString);
    VMA_ASSERT(m_Stack.empty());
}

void VmaJsonWriter::BeginObject(bool singleLine)
{
    VMA_ASSERT(!m_InsideString);

    BeginValue(false);
    m_SB.Add('{');

    StackItem item;
    item.type = COLLECTION_TYPE_OBJECT;
    item.valueCount = 0;
    item.singleLineMode = singleLine;
    m_Stack.push_back(item);
}

void VmaJsonWriter::EndObject()
{
    VMA_ASSERT(!m_InsideString);

    WriteIndent(true);
    m_SB.Add('}');

    VMA_ASSERT(!m_Stack.empty() && m_Stack.back().type == COLLECTION_TYPE_OBJECT);
    m_Stack.pop_back();
}

void VmaJsonWriter::BeginArray(bool singleLine)
{
    VMA_ASSERT(!m_InsideString);

    BeginValue(false);
    m_SB.Add('[');

    StackItem item;
    item.type = COLLECTION_TYPE_ARRAY;
    item.valueCount = 0;
    item.singleLineMode = singleLine;
    m_Stack.push_back(item);
}

void VmaJsonWriter::EndArray()
{
    VMA_ASSERT(!m_InsideString);

    WriteIndent(true);
    m_SB.Add(']');

    VMA_ASSERT(!m_Stack.empty() && m_Stack.back().type == COLLECTION_TYPE_ARRAY);
    m_Stack.pop_back();
}

void VmaJsonWriter::WriteString(const char* pStr)
{
    BeginString(pStr);
    EndString();
}

void VmaJsonWriter::BeginString(const char* pStr)
{
    VMA_ASSERT(!m_InsideString);

    BeginValue(true);
    m_SB.Add('"');
    m_InsideString = true;
    if(pStr != VMA_NULL && pStr[0] != '\0')
    {
        ContinueString(pStr);
    }
}

void VmaJsonWriter::ContinueString(const char* pStr)
{
    VMA_ASSERT(m_InsideString);

    const size_t strLen = strlen(pStr);
    for(size_t i = 0; i < strLen; ++i)
    {
        char ch = pStr[i];
        if(ch == '\\')
        {
            m_SB.Add("\\\\");
        }
        else if(ch == '"')
        {
            m_SB.Add("\\\"");
        }
        else if(ch >= 32)
        {
            m_SB.Add(ch);
        }
        else switch(ch)
        {
        case '\b':
            m_SB.Add("\\b");
            break;
        case '\f':
            m_SB.Add("\\f");
            break;
        case '\n':
            m_SB.Add("\\n");
            break;
        case '\r':
            m_SB.Add("\\r");
            break;
        case '\t':
            m_SB.Add("\\t");
            break;
        default:
            VMA_ASSERT(0 && "Character not currently supported.");
            break;
        }
    }
}

void VmaJsonWriter::ContinueString(uint32_t n)
{
    VMA_ASSERT(m_InsideString);
    m_SB.AddNumber(n);
}

void VmaJsonWriter::ContinueString(uint64_t n)
{
    VMA_ASSERT(m_InsideString);
    m_SB.AddNumber(n);
}

void VmaJsonWriter::ContinueString_Pointer(const void* ptr)
{
    VMA_ASSERT(m_InsideString);
    m_SB.AddPointer(ptr);
}

void VmaJsonWriter::EndString(const char* pStr)
{
    VMA_ASSERT(m_InsideString);
    if(pStr != VMA_NULL && pStr[0] != '\0')
    {
        ContinueString(pStr);
    }
    m_SB.Add('"');
    m_InsideString = false;
}

void VmaJsonWriter::WriteNumber(uint32_t n)
{
    VMA_ASSERT(!m_InsideString);
    BeginValue(false);
    m_SB.AddNumber(n);
}

void VmaJsonWriter::WriteNumber(uint64_t n)
{
    VMA_ASSERT(!m_InsideString);
    BeginValue(false);
    m_SB.AddNumber(n);
}

void VmaJsonWriter::WriteBool(bool b)
{
    VMA_ASSERT(!m_InsideString);
    BeginValue(false);
    m_SB.Add(b ? "true" : "false");
}

void VmaJsonWriter::WriteNull()
{
    VMA_ASSERT(!m_InsideString);
    BeginValue(false);
    m_SB.Add("null");
}

void VmaJsonWriter::BeginValue(bool isString)
{
    if(!m_Stack.empty())
    {
        StackItem& currItem = m_Stack.back();
        if(currItem.type == COLLECTION_TYPE_OBJECT &&
            currItem.valueCount % 2 == 0)
        {
            VMA_ASSERT(isString);
        }

        if(currItem.type == COLLECTION_TYPE_OBJECT &&
            currItem.valueCount % 2 != 0)
        {
            m_SB.Add(": ");
        }
        else if(currItem.valueCount > 0)
        {
            m_SB.Add(", ");
            WriteIndent();
        }
        else
        {
            WriteIndent();
        }
        ++currItem.valueCount;
    }
}

void VmaJsonWriter::WriteIndent(bool oneLess)
{
    if(!m_Stack.empty() && !m_Stack.back().singleLineMode)
    {
        m_SB.AddNewLine();
        
        size_t count = m_Stack.size();
        if(count > 0 && oneLess)
        {
            --count;
        }
        for(size_t i = 0; i < count; ++i)
        {
            m_SB.Add(INDENT);
        }
    }
}

#endif // #if VMA_STATS_STRING_ENABLED


void VmaAllocation_T::SetUserData(VmaAllocator hAllocator, void* pUserData)
{
    if(IsUserDataString())
    {
        VMA_ASSERT(pUserData == VMA_NULL || pUserData != m_pUserData);

        FreeUserDataString(hAllocator);

        if(pUserData != VMA_NULL)
        {
            const char* const newStrSrc = (char*)pUserData;
            const size_t newStrLen = strlen(newStrSrc);
            char* const newStrDst = vma_new_array(hAllocator, char, newStrLen + 1);
            memcpy(newStrDst, newStrSrc, newStrLen + 1);
            m_pUserData = newStrDst;
        }
    }
    else
    {
        m_pUserData = pUserData;
    }
}

void VmaAllocation_T::ChangeBlockAllocation(
    VmaAllocator hAllocator,
    VmaDeviceMemoryBlock* block,
    VkDeviceSize offset)
{
    VMA_ASSERT(block != VMA_NULL);
    VMA_ASSERT(m_Type == ALLOCATION_TYPE_BLOCK);

    // Move mapping reference counter from old block to new block.
    if(block != m_BlockAllocation.m_Block)
    {
        uint32_t mapRefCount = m_MapCount & ~MAP_COUNT_FLAG_PERSISTENT_MAP;
        if(IsPersistentMap())
            ++mapRefCount;
        m_BlockAllocation.m_Block->Unmap(hAllocator, mapRefCount);
        block->Map(hAllocator, mapRefCount, VMA_NULL);
    }

    m_BlockAllocation.m_Block = block;
    m_BlockAllocation.m_Offset = offset;
}

void VmaAllocation_T::ChangeSize(VkDeviceSize newSize)
{
    VMA_ASSERT(newSize > 0);
    m_Size = newSize;
}

void VmaAllocation_T::ChangeOffset(VkDeviceSize newOffset)
{
    VMA_ASSERT(m_Type == ALLOCATION_TYPE_BLOCK);
    m_BlockAllocation.m_Offset = newOffset;
}

VkDeviceSize VmaAllocation_T::GetOffset() const
{
    switch(m_Type)
    {
    case ALLOCATION_TYPE_BLOCK:
        return m_BlockAllocation.m_Offset;
    case ALLOCATION_TYPE_DEDICATED:
        return 0;
    default:
        VMA_ASSERT(0);
        return 0;
    }
}

VkDeviceMemory VmaAllocation_T::GetMemory() const
{
    switch(m_Type)
    {
    case ALLOCATION_TYPE_BLOCK:
        return m_BlockAllocation.m_Block->GetDeviceMemory();
    case ALLOCATION_TYPE_DEDICATED:
        return m_DedicatedAllocation.m_hMemory;
    default:
        VMA_ASSERT(0);
        return VK_NULL_HANDLE;
    }
}

uint32_t VmaAllocation_T::GetMemoryTypeIndex() const
{
    switch(m_Type)
    {
    case ALLOCATION_TYPE_BLOCK:
        return m_BlockAllocation.m_Block->GetMemoryTypeIndex();
    case ALLOCATION_TYPE_DEDICATED:
        return m_DedicatedAllocation.m_MemoryTypeIndex;
    default:
        VMA_ASSERT(0);
        return UINT32_MAX;
    }
}

void* VmaAllocation_T::GetMappedData() const
{
    switch(m_Type)
    {
    case ALLOCATION_TYPE_BLOCK:
        if(m_MapCount != 0)
        {
            void* pBlockData = m_BlockAllocation.m_Block->GetMappedData();
            VMA_ASSERT(pBlockData != VMA_NULL);
            return (char*)pBlockData + m_BlockAllocation.m_Offset;
        }
        else
        {
            return VMA_NULL;
        }
        break;
    case ALLOCATION_TYPE_DEDICATED:
        VMA_ASSERT((m_DedicatedAllocation.m_pMappedData != VMA_NULL) == (m_MapCount != 0));
        return m_DedicatedAllocation.m_pMappedData;
    default:
        VMA_ASSERT(0);
        return VMA_NULL;
    }
}

bool VmaAllocation_T::CanBecomeLost() const
{
    switch(m_Type)
    {
    case ALLOCATION_TYPE_BLOCK:
        return m_BlockAllocation.m_CanBecomeLost;
    case ALLOCATION_TYPE_DEDICATED:
        return false;
    default:
        VMA_ASSERT(0);
        return false;
    }
}

bool VmaAllocation_T::MakeLost(uint32_t currentFrameIndex, uint32_t frameInUseCount)
{
    VMA_ASSERT(CanBecomeLost());

    /*
    Warning: This is a carefully designed algorithm.
    Do not modify unless you really know what you're doing :)
    */
    uint32_t localLastUseFrameIndex = GetLastUseFrameIndex();
    for(;;)
    {
        if(localLastUseFrameIndex == VMA_FRAME_INDEX_LOST)
        {
            VMA_ASSERT(0);
            return false;
        }
        else if(localLastUseFrameIndex + frameInUseCount >= currentFrameIndex)
        {
            return false;
        }
        else // Last use time earlier than current time.
        {
            if(CompareExchangeLastUseFrameIndex(localLastUseFrameIndex, VMA_FRAME_INDEX_LOST))
            {
                // Setting hAllocation.LastUseFrameIndex atomic to VMA_FRAME_INDEX_LOST is enough to mark it as LOST.
                // Calling code just needs to unregister this allocation in owning VmaDeviceMemoryBlock.
                return true;
            }
        }
    }
}

#if VMA_STATS_STRING_ENABLED

// Correspond to values of enum VmaSuballocationType.
static const char* VMA_SUBALLOCATION_TYPE_NAMES[] = {
    "FREE",
    "UNKNOWN",
    "BUFFER",
    "IMAGE_UNKNOWN",
    "IMAGE_LINEAR",
    "IMAGE_OPTIMAL",
};

void VmaAllocation_T::PrintParameters(class VmaJsonWriter& json) const
{
    json.WriteString("Type");
    json.WriteString(VMA_SUBALLOCATION_TYPE_NAMES[m_SuballocationType]);

    json.WriteString("Size");
    json.WriteNumber(m_Size);

    if(m_pUserData != VMA_NULL)
    {
        json.WriteString("UserData");
        if(IsUserDataString())
        {
            json.WriteString((const char*)m_pUserData);
        }
        else
        {
            json.BeginString();
            json.ContinueString_Pointer(m_pUserData);
            json.EndString();
        }
    }

    json.WriteString("CreationFrameIndex");
    json.WriteNumber(m_CreationFrameIndex);

    json.WriteString("LastUseFrameIndex");
    json.WriteNumber(GetLastUseFrameIndex());

    if(m_BufferImageUsage != 0)
    {
        json.WriteString("Usage");
        json.WriteNumber(m_BufferImageUsage);
    }
}

#endif

void VmaAllocation_T::FreeUserDataString(VmaAllocator hAllocator)
{
    VMA_ASSERT(IsUserDataString());
    if(m_pUserData != VMA_NULL)
    {
        char* const oldStr = (char*)m_pUserData;
        const size_t oldStrLen = strlen(oldStr);
        vma_delete_array(hAllocator, oldStr, oldStrLen + 1);
        m_pUserData = VMA_NULL;
    }
}

void VmaAllocation_T::BlockAllocMap()
{
    VMA_ASSERT(GetType() == ALLOCATION_TYPE_BLOCK);

    if((m_MapCount & ~MAP_COUNT_FLAG_PERSISTENT_MAP) < 0x7F)
    {
        ++m_MapCount;
    }
    else
    {
        VMA_ASSERT(0 && "Allocation mapped too many times simultaneously.");
    }
}

void VmaAllocation_T::BlockAllocUnmap()
{
    VMA_ASSERT(GetType() == ALLOCATION_TYPE_BLOCK);

    if((m_MapCount & ~MAP_COUNT_FLAG_PERSISTENT_MAP) != 0)
    {
        --m_MapCount;
    }
    else
    {
        VMA_ASSERT(0 && "Unmapping allocation not previously mapped.");
    }
}

VkResult VmaAllocation_T::DedicatedAllocMap(VmaAllocator hAllocator, void** ppData)
{
    VMA_ASSERT(GetType() == ALLOCATION_TYPE_DEDICATED);

    if(m_MapCount != 0)
    {
        if((m_MapCount & ~MAP_COUNT_FLAG_PERSISTENT_MAP) < 0x7F)
        {
            VMA_ASSERT(m_DedicatedAllocation.m_pMappedData != VMA_NULL);
            *ppData = m_DedicatedAllocation.m_pMappedData;
            ++m_MapCount;
            return VK_SUCCESS;
        }
        else
        {
            VMA_ASSERT(0 && "Dedicated allocation mapped too many times simultaneously.");
            return VK_ERROR_MEMORY_MAP_FAILED;
        }
    }
    else
    {
        VkResult result = (*hAllocator->GetVulkanFunctions().vkMapMemory)(
            hAllocator->m_hDevice,
            m_DedicatedAllocation.m_hMemory,
            0, // offset
            VK_WHOLE_SIZE,
            0, // flags
            ppData);
        if(result == VK_SUCCESS)
        {
            m_DedicatedAllocation.m_pMappedData = *ppData;
            m_MapCount = 1;
        }
        return result;
    }
}

void VmaAllocation_T::DedicatedAllocUnmap(VmaAllocator hAllocator)
{
    VMA_ASSERT(GetType() == ALLOCATION_TYPE_DEDICATED);

    if((m_MapCount & ~MAP_COUNT_FLAG_PERSISTENT_MAP) != 0)
    {
        --m_MapCount;
        if(m_MapCount == 0)
        {
            m_DedicatedAllocation.m_pMappedData = VMA_NULL;
            (*hAllocator->GetVulkanFunctions().vkUnmapMemory)(
                hAllocator->m_hDevice,
                m_DedicatedAllocation.m_hMemory);
        }
    }
    else
    {
        VMA_ASSERT(0 && "Unmapping dedicated allocation not previously mapped.");
    }
}

#if VMA_STATS_STRING_ENABLED

static void VmaPrintStatInfo(VmaJsonWriter& json, const VmaStatInfo& stat)
{
    json.BeginObject();

    json.WriteString("Blocks");
    json.WriteNumber(stat.blockCount);

    json.WriteString("Allocations");
    json.WriteNumber(stat.allocationCount);

    json.WriteString("UnusedRanges");
    json.WriteNumber(stat.unusedRangeCount);

    json.WriteString("UsedBytes");
    json.WriteNumber(stat.usedBytes);

    json.WriteString("UnusedBytes");
    json.WriteNumber(stat.unusedBytes);

    if(stat.allocationCount > 1)
    {
        json.WriteString("AllocationSize");
        json.BeginObject(true);
        json.WriteString("Min");
        json.WriteNumber(stat.allocationSizeMin);
        json.WriteString("Avg");
        json.WriteNumber(stat.allocationSizeAvg);
        json.WriteString("Max");
        json.WriteNumber(stat.allocationSizeMax);
        json.EndObject();
    }

    if(stat.unusedRangeCount > 1)
    {
        json.WriteString("UnusedRangeSize");
        json.BeginObject(true);
        json.WriteString("Min");
        json.WriteNumber(stat.unusedRangeSizeMin);
        json.WriteString("Avg");
        json.WriteNumber(stat.unusedRangeSizeAvg);
        json.WriteString("Max");
        json.WriteNumber(stat.unusedRangeSizeMax);
        json.EndObject();
    }

    json.EndObject();
}

#endif // #if VMA_STATS_STRING_ENABLED

struct VmaSuballocationItemSizeLess
{
    bool operator()(
        const VmaSuballocationList::iterator lhs,
        const VmaSuballocationList::iterator rhs) const
    {
        return lhs->size < rhs->size;
    }
    bool operator()(
        const VmaSuballocationList::iterator lhs,
        VkDeviceSize rhsSize) const
    {
        return lhs->size < rhsSize;
    }
};


// class VmaBlockMetadata

VmaBlockMetadata::VmaBlockMetadata(VmaAllocator hAllocator) :
    m_Size(0),
    m_pAllocationCallbacks(hAllocator->GetAllocationCallbacks())
{
}

#if VMA_STATS_STRING_ENABLED

void VmaBlockMetadata::PrintDetailedMap_Begin(class VmaJsonWriter& json,
    VkDeviceSize unusedBytes,
    size_t allocationCount,
    size_t unusedRangeCount) const
{
    json.BeginObject();

    json.WriteString("TotalBytes");
    json.WriteNumber(GetSize());

    json.WriteString("UnusedBytes");
    json.WriteNumber(unusedBytes);

    json.WriteString("Allocations");
    json.WriteNumber((uint64_t)allocationCount);

    json.WriteString("UnusedRanges");
    json.WriteNumber((uint64_t)unusedRangeCount);

    json.WriteString("Suballocations");
    json.BeginArray();
}

void VmaBlockMetadata::PrintDetailedMap_Allocation(class VmaJsonWriter& json,
    VkDeviceSize offset,
    VmaAllocation hAllocation) const
{
    json.BeginObject(true);
        
    json.WriteString("Offset");
    json.WriteNumber(offset);

    hAllocation->PrintParameters(json);

    json.EndObject();
}

void VmaBlockMetadata::PrintDetailedMap_UnusedRange(class VmaJsonWriter& json,
    VkDeviceSize offset,
    VkDeviceSize size) const
{
    json.BeginObject(true);
        
    json.WriteString("Offset");
    json.WriteNumber(offset);

    json.WriteString("Type");
    json.WriteString(VMA_SUBALLOCATION_TYPE_NAMES[VMA_SUBALLOCATION_TYPE_FREE]);

    json.WriteString("Size");
    json.WriteNumber(size);

    json.EndObject();
}

void VmaBlockMetadata::PrintDetailedMap_End(class VmaJsonWriter& json) const
{
    json.EndArray();
    json.EndObject();
}

#endif // #if VMA_STATS_STRING_ENABLED

// class VmaBlockMetadata_Generic

VmaBlockMetadata_Generic::VmaBlockMetadata_Generic(VmaAllocator hAllocator) :
    VmaBlockMetadata(hAllocator),
    m_FreeCount(0),
    m_SumFreeSize(0),
    m_Suballocations(VmaStlAllocator<VmaSuballocation>(hAllocator->GetAllocationCallbacks())),
    m_FreeSuballocationsBySize(VmaStlAllocator<VmaSuballocationList::iterator>(hAllocator->GetAllocationCallbacks()))
{
}

VmaBlockMetadata_Generic::~VmaBlockMetadata_Generic()
{
}

void VmaBlockMetadata_Generic::Init(VkDeviceSize size)
{
    VmaBlockMetadata::Init(size);

    m_FreeCount = 1;
    m_SumFreeSize = size;

    VmaSuballocation suballoc = {};
    suballoc.offset = 0;
    suballoc.size = size;
    suballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
    suballoc.hAllocation = VK_NULL_HANDLE;

    VMA_ASSERT(size > VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER);
    m_Suballocations.push_back(suballoc);
    VmaSuballocationList::iterator suballocItem = m_Suballocations.end();
    --suballocItem;
    m_FreeSuballocationsBySize.push_back(suballocItem);
}

bool VmaBlockMetadata_Generic::Validate() const
{
    VMA_VALIDATE(!m_Suballocations.empty());
    
    // Expected offset of new suballocation as calculated from previous ones.
    VkDeviceSize calculatedOffset = 0;
    // Expected number of free suballocations as calculated from traversing their list.
    uint32_t calculatedFreeCount = 0;
    // Expected sum size of free suballocations as calculated from traversing their list.
    VkDeviceSize calculatedSumFreeSize = 0;
    // Expected number of free suballocations that should be registered in
    // m_FreeSuballocationsBySize calculated from traversing their list.
    size_t freeSuballocationsToRegister = 0;
    // True if previous visited suballocation was free.
    bool prevFree = false;

    for(VmaSuballocationList::const_iterator suballocItem = m_Suballocations.cbegin();
        suballocItem != m_Suballocations.cend();
        ++suballocItem)
    {
        const VmaSuballocation& subAlloc = *suballocItem;
        
        // Actual offset of this suballocation doesn't match expected one.
        VMA_VALIDATE(subAlloc.offset == calculatedOffset);

        const bool currFree = (subAlloc.type == VMA_SUBALLOCATION_TYPE_FREE);
        // Two adjacent free suballocations are invalid. They should be merged.
        VMA_VALIDATE(!prevFree || !currFree);

        VMA_VALIDATE(currFree == (subAlloc.hAllocation == VK_NULL_HANDLE));

        if(currFree)
        {
            calculatedSumFreeSize += subAlloc.size;
            ++calculatedFreeCount;
            if(subAlloc.size >= VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER)
            {
                ++freeSuballocationsToRegister;
            }

            // Margin required between allocations - every free space must be at least that large.
            VMA_VALIDATE(subAlloc.size >= VMA_DEBUG_MARGIN);
        }
        else
        {
            VMA_VALIDATE(subAlloc.hAllocation->GetOffset() == subAlloc.offset);
            VMA_VALIDATE(subAlloc.hAllocation->GetSize() == subAlloc.size);

            // Margin required between allocations - previous allocation must be free.
            VMA_VALIDATE(VMA_DEBUG_MARGIN == 0 || prevFree);
        }

        calculatedOffset += subAlloc.size;
        prevFree = currFree;
    }

    // Number of free suballocations registered in m_FreeSuballocationsBySize doesn't
    // match expected one.
    VMA_VALIDATE(m_FreeSuballocationsBySize.size() == freeSuballocationsToRegister);

    VkDeviceSize lastSize = 0;
    for(size_t i = 0; i < m_FreeSuballocationsBySize.size(); ++i)
    {
        VmaSuballocationList::iterator suballocItem = m_FreeSuballocationsBySize[i];
        
        // Only free suballocations can be registered in m_FreeSuballocationsBySize.
        VMA_VALIDATE(suballocItem->type == VMA_SUBALLOCATION_TYPE_FREE);
        // They must be sorted by size ascending.
        VMA_VALIDATE(suballocItem->size >= lastSize);

        lastSize = suballocItem->size;
    }

    // Check if totals match calculacted values.
    VMA_VALIDATE(ValidateFreeSuballocationList());
    VMA_VALIDATE(calculatedOffset == GetSize());
    VMA_VALIDATE(calculatedSumFreeSize == m_SumFreeSize);
    VMA_VALIDATE(calculatedFreeCount == m_FreeCount);

    return true;
}

VkDeviceSize VmaBlockMetadata_Generic::GetUnusedRangeSizeMax() const
{
    if(!m_FreeSuballocationsBySize.empty())
    {
        return m_FreeSuballocationsBySize.back()->size;
    }
    else
    {
        return 0;
    }
}

bool VmaBlockMetadata_Generic::IsEmpty() const
{
    return (m_Suballocations.size() == 1) && (m_FreeCount == 1);
}

void VmaBlockMetadata_Generic::CalcAllocationStatInfo(VmaStatInfo& outInfo) const
{
    outInfo.blockCount = 1;

    const uint32_t rangeCount = (uint32_t)m_Suballocations.size();
    outInfo.allocationCount = rangeCount - m_FreeCount;
    outInfo.unusedRangeCount = m_FreeCount;
    
    outInfo.unusedBytes = m_SumFreeSize;
    outInfo.usedBytes = GetSize() - outInfo.unusedBytes;

    outInfo.allocationSizeMin = UINT64_MAX;
    outInfo.allocationSizeMax = 0;
    outInfo.unusedRangeSizeMin = UINT64_MAX;
    outInfo.unusedRangeSizeMax = 0;

    for(VmaSuballocationList::const_iterator suballocItem = m_Suballocations.cbegin();
        suballocItem != m_Suballocations.cend();
        ++suballocItem)
    {
        const VmaSuballocation& suballoc = *suballocItem;
        if(suballoc.type != VMA_SUBALLOCATION_TYPE_FREE)
        {
            outInfo.allocationSizeMin = VMA_MIN(outInfo.allocationSizeMin, suballoc.size);
            outInfo.allocationSizeMax = VMA_MAX(outInfo.allocationSizeMax, suballoc.size);
        }
        else
        {
            outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, suballoc.size);
            outInfo.unusedRangeSizeMax = VMA_MAX(outInfo.unusedRangeSizeMax, suballoc.size);
        }
    }
}

void VmaBlockMetadata_Generic::AddPoolStats(VmaPoolStats& inoutStats) const
{
    const uint32_t rangeCount = (uint32_t)m_Suballocations.size();

    inoutStats.size += GetSize();
    inoutStats.unusedSize += m_SumFreeSize;
    inoutStats.allocationCount += rangeCount - m_FreeCount;
    inoutStats.unusedRangeCount += m_FreeCount;
    inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, GetUnusedRangeSizeMax());
}

#if VMA_STATS_STRING_ENABLED

void VmaBlockMetadata_Generic::PrintDetailedMap(class VmaJsonWriter& json) const
{
    PrintDetailedMap_Begin(json,
        m_SumFreeSize, // unusedBytes
        m_Suballocations.size() - (size_t)m_FreeCount, // allocationCount
        m_FreeCount); // unusedRangeCount

    size_t i = 0;
    for(VmaSuballocationList::const_iterator suballocItem = m_Suballocations.cbegin();
        suballocItem != m_Suballocations.cend();
        ++suballocItem, ++i)
    {
        if(suballocItem->type == VMA_SUBALLOCATION_TYPE_FREE)
        {
            PrintDetailedMap_UnusedRange(json, suballocItem->offset, suballocItem->size);
        }
        else
        {
            PrintDetailedMap_Allocation(json, suballocItem->offset, suballocItem->hAllocation);
        }
    }

    PrintDetailedMap_End(json);
}

#endif // #if VMA_STATS_STRING_ENABLED

bool VmaBlockMetadata_Generic::CreateAllocationRequest(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VkDeviceSize bufferImageGranularity,
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    bool upperAddress,
    VmaSuballocationType allocType,
    bool canMakeOtherLost,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{
    VMA_ASSERT(allocSize > 0);
    VMA_ASSERT(!upperAddress);
    VMA_ASSERT(allocType != VMA_SUBALLOCATION_TYPE_FREE);
    VMA_ASSERT(pAllocationRequest != VMA_NULL);
    VMA_HEAVY_ASSERT(Validate());

    pAllocationRequest->type = VmaAllocationRequestType::Normal;

    // There is not enough total free space in this block to fullfill the request: Early return.
    if(canMakeOtherLost == false &&
        m_SumFreeSize < allocSize + 2 * VMA_DEBUG_MARGIN)
    {
        return false;
    }

    // New algorithm, efficiently searching freeSuballocationsBySize.
    const size_t freeSuballocCount = m_FreeSuballocationsBySize.size();
    if(freeSuballocCount > 0)
    {
        if(strategy == VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT)
        {
            // Find first free suballocation with size not less than allocSize + 2 * VMA_DEBUG_MARGIN.
            VmaSuballocationList::iterator* const it = VmaBinaryFindFirstNotLess(
                m_FreeSuballocationsBySize.data(),
                m_FreeSuballocationsBySize.data() + freeSuballocCount,
                allocSize + 2 * VMA_DEBUG_MARGIN,
                VmaSuballocationItemSizeLess());
            size_t index = it - m_FreeSuballocationsBySize.data();
            for(; index < freeSuballocCount; ++index)
            {
                if(CheckAllocation(
                    currentFrameIndex,
                    frameInUseCount,
                    bufferImageGranularity,
                    allocSize,
                    allocAlignment,
                    allocType,
                    m_FreeSuballocationsBySize[index],
                    false, // canMakeOtherLost
                    &pAllocationRequest->offset,
                    &pAllocationRequest->itemsToMakeLostCount,
                    &pAllocationRequest->sumFreeSize,
                    &pAllocationRequest->sumItemSize))
                {
                    pAllocationRequest->item = m_FreeSuballocationsBySize[index];
                    return true;
                }
            }
        }
        else if(strategy == VMA_ALLOCATION_INTERNAL_STRATEGY_MIN_OFFSET)
        {
            for(VmaSuballocationList::iterator it = m_Suballocations.begin();
                it != m_Suballocations.end();
                ++it)
            {
                if(it->type == VMA_SUBALLOCATION_TYPE_FREE && CheckAllocation(
                    currentFrameIndex,
                    frameInUseCount,
                    bufferImageGranularity,
                    allocSize,
                    allocAlignment,
                    allocType,
                    it,
                    false, // canMakeOtherLost
                    &pAllocationRequest->offset,
                    &pAllocationRequest->itemsToMakeLostCount,
                    &pAllocationRequest->sumFreeSize,
                    &pAllocationRequest->sumItemSize))
                {
                    pAllocationRequest->item = it;
                    return true;
                }
            }
        }
        else // WORST_FIT, FIRST_FIT
        {
            // Search staring from biggest suballocations.
            for(size_t index = freeSuballocCount; index--; )
            {
                if(CheckAllocation(
                    currentFrameIndex,
                    frameInUseCount,
                    bufferImageGranularity,
                    allocSize,
                    allocAlignment,
                    allocType,
                    m_FreeSuballocationsBySize[index],
                    false, // canMakeOtherLost
                    &pAllocationRequest->offset,
                    &pAllocationRequest->itemsToMakeLostCount,
                    &pAllocationRequest->sumFreeSize,
                    &pAllocationRequest->sumItemSize))
                {
                    pAllocationRequest->item = m_FreeSuballocationsBySize[index];
                    return true;
                }
            }
        }
    }

    if(canMakeOtherLost)
    {
        // Brute-force algorithm. TODO: Come up with something better.

        bool found = false;
        VmaAllocationRequest tmpAllocRequest = {};
        tmpAllocRequest.type = VmaAllocationRequestType::Normal;
        for(VmaSuballocationList::iterator suballocIt = m_Suballocations.begin();
            suballocIt != m_Suballocations.end();
            ++suballocIt)
        {
            if(suballocIt->type == VMA_SUBALLOCATION_TYPE_FREE ||
                suballocIt->hAllocation->CanBecomeLost())
            {
                if(CheckAllocation(
                    currentFrameIndex,
                    frameInUseCount,
                    bufferImageGranularity,
                    allocSize,
                    allocAlignment,
                    allocType,
                    suballocIt,
                    canMakeOtherLost,
                    &tmpAllocRequest.offset,
                    &tmpAllocRequest.itemsToMakeLostCount,
                    &tmpAllocRequest.sumFreeSize,
                    &tmpAllocRequest.sumItemSize))
                {
                    if(strategy == VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT)
                    {
                        *pAllocationRequest = tmpAllocRequest;
                        pAllocationRequest->item = suballocIt;
                        break;
                    }
                    if(!found || tmpAllocRequest.CalcCost() < pAllocationRequest->CalcCost())
                    {
                        *pAllocationRequest = tmpAllocRequest;
                        pAllocationRequest->item = suballocIt;
                        found = true;
                    }
                }
            }
        }

        return found;
    }

    return false;
}

bool VmaBlockMetadata_Generic::MakeRequestedAllocationsLost(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VmaAllocationRequest* pAllocationRequest)
{
    VMA_ASSERT(pAllocationRequest && pAllocationRequest->type == VmaAllocationRequestType::Normal);

    while(pAllocationRequest->itemsToMakeLostCount > 0)
    {
        if(pAllocationRequest->item->type == VMA_SUBALLOCATION_TYPE_FREE)
        {
            ++pAllocationRequest->item;
        }
        VMA_ASSERT(pAllocationRequest->item != m_Suballocations.end());
        VMA_ASSERT(pAllocationRequest->item->hAllocation != VK_NULL_HANDLE);
        VMA_ASSERT(pAllocationRequest->item->hAllocation->CanBecomeLost());
        if(pAllocationRequest->item->hAllocation->MakeLost(currentFrameIndex, frameInUseCount))
        {
            pAllocationRequest->item = FreeSuballocation(pAllocationRequest->item);
            --pAllocationRequest->itemsToMakeLostCount;
        }
        else
        {
            return false;
        }
    }

    VMA_HEAVY_ASSERT(Validate());
    VMA_ASSERT(pAllocationRequest->item != m_Suballocations.end());
    VMA_ASSERT(pAllocationRequest->item->type == VMA_SUBALLOCATION_TYPE_FREE);
    
    return true;
}

uint32_t VmaBlockMetadata_Generic::MakeAllocationsLost(uint32_t currentFrameIndex, uint32_t frameInUseCount)
{
    uint32_t lostAllocationCount = 0;
    for(VmaSuballocationList::iterator it = m_Suballocations.begin();
        it != m_Suballocations.end();
        ++it)
    {
        if(it->type != VMA_SUBALLOCATION_TYPE_FREE &&
            it->hAllocation->CanBecomeLost() &&
            it->hAllocation->MakeLost(currentFrameIndex, frameInUseCount))
        {
            it = FreeSuballocation(it);
            ++lostAllocationCount;
        }
    }
    return lostAllocationCount;
}

VkResult VmaBlockMetadata_Generic::CheckCorruption(const void* pBlockData)
{
    for(VmaSuballocationList::iterator it = m_Suballocations.begin();
        it != m_Suballocations.end();
        ++it)
    {
        if(it->type != VMA_SUBALLOCATION_TYPE_FREE)
        {
            if(!VmaValidateMagicValue(pBlockData, it->offset - VMA_DEBUG_MARGIN))
            {
                VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED BEFORE VALIDATED ALLOCATION!");
                return VK_ERROR_VALIDATION_FAILED_EXT;
            }
            if(!VmaValidateMagicValue(pBlockData, it->offset + it->size))
            {
                VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED AFTER VALIDATED ALLOCATION!");
                return VK_ERROR_VALIDATION_FAILED_EXT;
            }
        }
    }

    return VK_SUCCESS;
}

void VmaBlockMetadata_Generic::Alloc(
    const VmaAllocationRequest& request,
    VmaSuballocationType type,
    VkDeviceSize allocSize,
    VmaAllocation hAllocation)
{
    VMA_ASSERT(request.type == VmaAllocationRequestType::Normal);
    VMA_ASSERT(request.item != m_Suballocations.end());
    VmaSuballocation& suballoc = *request.item;
    // Given suballocation is a free block.
    VMA_ASSERT(suballoc.type == VMA_SUBALLOCATION_TYPE_FREE);
    // Given offset is inside this suballocation.
    VMA_ASSERT(request.offset >= suballoc.offset);
    const VkDeviceSize paddingBegin = request.offset - suballoc.offset;
    VMA_ASSERT(suballoc.size >= paddingBegin + allocSize);
    const VkDeviceSize paddingEnd = suballoc.size - paddingBegin - allocSize;

    // Unregister this free suballocation from m_FreeSuballocationsBySize and update
    // it to become used.
    UnregisterFreeSuballocation(request.item);

    suballoc.offset = request.offset;
    suballoc.size = allocSize;
    suballoc.type = type;
    suballoc.hAllocation = hAllocation;

    // If there are any free bytes remaining at the end, insert new free suballocation after current one.
    if(paddingEnd)
    {
        VmaSuballocation paddingSuballoc = {};
        paddingSuballoc.offset = request.offset + allocSize;
        paddingSuballoc.size = paddingEnd;
        paddingSuballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
        VmaSuballocationList::iterator next = request.item;
        ++next;
        const VmaSuballocationList::iterator paddingEndItem =
            m_Suballocations.insert(next, paddingSuballoc);
        RegisterFreeSuballocation(paddingEndItem);
    }

    // If there are any free bytes remaining at the beginning, insert new free suballocation before current one.
    if(paddingBegin)
    {
        VmaSuballocation paddingSuballoc = {};
        paddingSuballoc.offset = request.offset - paddingBegin;
        paddingSuballoc.size = paddingBegin;
        paddingSuballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
        const VmaSuballocationList::iterator paddingBeginItem =
            m_Suballocations.insert(request.item, paddingSuballoc);
        RegisterFreeSuballocation(paddingBeginItem);
    }

    // Update totals.
    m_FreeCount = m_FreeCount - 1;
    if(paddingBegin > 0)
    {
        ++m_FreeCount;
    }
    if(paddingEnd > 0)
    {
        ++m_FreeCount;
    }
    m_SumFreeSize -= allocSize;
}

void VmaBlockMetadata_Generic::Free(const VmaAllocation allocation)
{
    for(VmaSuballocationList::iterator suballocItem = m_Suballocations.begin();
        suballocItem != m_Suballocations.end();
        ++suballocItem)
    {
        VmaSuballocation& suballoc = *suballocItem;
        if(suballoc.hAllocation == allocation)
        {
            FreeSuballocation(suballocItem);
            VMA_HEAVY_ASSERT(Validate());
            return;
        }
    }
    VMA_ASSERT(0 && "Not found!");
}

void VmaBlockMetadata_Generic::FreeAtOffset(VkDeviceSize offset)
{
    for(VmaSuballocationList::iterator suballocItem = m_Suballocations.begin();
        suballocItem != m_Suballocations.end();
        ++suballocItem)
    {
        VmaSuballocation& suballoc = *suballocItem;
        if(suballoc.offset == offset)
        {
            FreeSuballocation(suballocItem);
            return;
        }
    }
    VMA_ASSERT(0 && "Not found!");
}

bool VmaBlockMetadata_Generic::ResizeAllocation(const VmaAllocation alloc, VkDeviceSize newSize)
{
    typedef VmaSuballocationList::iterator iter_type;
    for(iter_type suballocItem = m_Suballocations.begin();
        suballocItem != m_Suballocations.end();
        ++suballocItem)
    {
        VmaSuballocation& suballoc = *suballocItem;
        if(suballoc.hAllocation == alloc)
        {
            iter_type nextItem = suballocItem;
            ++nextItem;

            // Should have been ensured on higher level.
            VMA_ASSERT(newSize != alloc->GetSize() && newSize > 0);

            // Shrinking.
            if(newSize < alloc->GetSize())
            {
                const VkDeviceSize sizeDiff = suballoc.size - newSize;

                // There is next item.
                if(nextItem != m_Suballocations.end())
                {
                    // Next item is free.
                    if(nextItem->type == VMA_SUBALLOCATION_TYPE_FREE)
                    {
                        // Grow this next item backward.
                        UnregisterFreeSuballocation(nextItem);
                        nextItem->offset -= sizeDiff;
                        nextItem->size += sizeDiff;
                        RegisterFreeSuballocation(nextItem);
                    }
                    // Next item is not free.
                    else
                    {
                        // Create free item after current one.
                        VmaSuballocation newFreeSuballoc;
                        newFreeSuballoc.hAllocation = VK_NULL_HANDLE;
                        newFreeSuballoc.offset = suballoc.offset + newSize;
                        newFreeSuballoc.size = sizeDiff;
                        newFreeSuballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
                        iter_type newFreeSuballocIt = m_Suballocations.insert(nextItem, newFreeSuballoc);
                        RegisterFreeSuballocation(newFreeSuballocIt);

                        ++m_FreeCount;
                    }
                }
                // This is the last item.
                else
                {
                    // Create free item at the end.
                    VmaSuballocation newFreeSuballoc;
                    newFreeSuballoc.hAllocation = VK_NULL_HANDLE;
                    newFreeSuballoc.offset = suballoc.offset + newSize;
                    newFreeSuballoc.size = sizeDiff;
                    newFreeSuballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
                    m_Suballocations.push_back(newFreeSuballoc);

                    iter_type newFreeSuballocIt = m_Suballocations.end();
                    RegisterFreeSuballocation(--newFreeSuballocIt);

                    ++m_FreeCount;
                }

                suballoc.size = newSize;
                m_SumFreeSize += sizeDiff;
            }
            // Growing.
            else
            {
                const VkDeviceSize sizeDiff = newSize - suballoc.size;

                // There is next item.
                if(nextItem != m_Suballocations.end())
                {
                    // Next item is free.
                    if(nextItem->type == VMA_SUBALLOCATION_TYPE_FREE)
                    {
                        // There is not enough free space, including margin.
                        if(nextItem->size < sizeDiff + VMA_DEBUG_MARGIN)
                        {
                            return false;
                        }

                        // There is more free space than required.
                        if(nextItem->size > sizeDiff)
                        {
                            // Move and shrink this next item.
                            UnregisterFreeSuballocation(nextItem);
                            nextItem->offset += sizeDiff;
                            nextItem->size -= sizeDiff;
                            RegisterFreeSuballocation(nextItem);
                        }
                        // There is exactly the amount of free space required.
                        else
                        {
                            // Remove this next free item.
                            UnregisterFreeSuballocation(nextItem);
                            m_Suballocations.erase(nextItem);
                            --m_FreeCount;
                        }
                    }
                    // Next item is not free - there is no space to grow.
                    else
                    {
                        return false;
                    }
                }
                // This is the last item - there is no space to grow.
                else
                {
                    return false;
                }

                suballoc.size = newSize;
                m_SumFreeSize -= sizeDiff;
            }

            // We cannot call Validate() here because alloc object is updated to new size outside of this call.
            return true;
        }
    }
    VMA_ASSERT(0 && "Not found!");
    return false;
}

bool VmaBlockMetadata_Generic::ValidateFreeSuballocationList() const
{
    VkDeviceSize lastSize = 0;
    for(size_t i = 0, count = m_FreeSuballocationsBySize.size(); i < count; ++i)
    {
        const VmaSuballocationList::iterator it = m_FreeSuballocationsBySize[i];

        VMA_VALIDATE(it->type == VMA_SUBALLOCATION_TYPE_FREE);
        VMA_VALIDATE(it->size >= VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER);
        VMA_VALIDATE(it->size >= lastSize);
        lastSize = it->size;
    }
    return true;
}

bool VmaBlockMetadata_Generic::CheckAllocation(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VkDeviceSize bufferImageGranularity,
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    VmaSuballocationType allocType,
    VmaSuballocationList::const_iterator suballocItem,
    bool canMakeOtherLost,
    VkDeviceSize* pOffset,
    size_t* itemsToMakeLostCount,
    VkDeviceSize* pSumFreeSize,
    VkDeviceSize* pSumItemSize) const
{
    VMA_ASSERT(allocSize > 0);
    VMA_ASSERT(allocType != VMA_SUBALLOCATION_TYPE_FREE);
    VMA_ASSERT(suballocItem != m_Suballocations.cend());
    VMA_ASSERT(pOffset != VMA_NULL);
    
    *itemsToMakeLostCount = 0;
    *pSumFreeSize = 0;
    *pSumItemSize = 0;

    if(canMakeOtherLost)
    {
        if(suballocItem->type == VMA_SUBALLOCATION_TYPE_FREE)
        {
            *pSumFreeSize = suballocItem->size;
        }
        else
        {
            if(suballocItem->hAllocation->CanBecomeLost() &&
                suballocItem->hAllocation->GetLastUseFrameIndex() + frameInUseCount < currentFrameIndex)
            {
                ++*itemsToMakeLostCount;
                *pSumItemSize = suballocItem->size;
            }
            else
            {
                return false;
            }
        }

        // Remaining size is too small for this request: Early return.
        if(GetSize() - suballocItem->offset < allocSize)
        {
            return false;
        }

        // Start from offset equal to beginning of this suballocation.
        *pOffset = suballocItem->offset;
    
        // Apply VMA_DEBUG_MARGIN at the beginning.
        if(VMA_DEBUG_MARGIN > 0)
        {
            *pOffset += VMA_DEBUG_MARGIN;
        }
    
        // Apply alignment.
        *pOffset = VmaAlignUp(*pOffset, allocAlignment);

        // Check previous suballocations for BufferImageGranularity conflicts.
        // Make bigger alignment if necessary.
        if(bufferImageGranularity > 1)
        {
            bool bufferImageGranularityConflict = false;
            VmaSuballocationList::const_iterator prevSuballocItem = suballocItem;
            while(prevSuballocItem != m_Suballocations.cbegin())
            {
                --prevSuballocItem;
                const VmaSuballocation& prevSuballoc = *prevSuballocItem;
                if(VmaBlocksOnSamePage(prevSuballoc.offset, prevSuballoc.size, *pOffset, bufferImageGranularity))
                {
                    if(VmaIsBufferImageGranularityConflict(prevSuballoc.type, allocType))
                    {
                        bufferImageGranularityConflict = true;
                        break;
                    }
                }
                else
                    // Already on previous page.
                    break;
            }
            if(bufferImageGranularityConflict)
            {
                *pOffset = VmaAlignUp(*pOffset, bufferImageGranularity);
            }
        }
    
        // Now that we have final *pOffset, check if we are past suballocItem.
        // If yes, return false - this function should be called for another suballocItem as starting point.
        if(*pOffset >= suballocItem->offset + suballocItem->size)
        {
            return false;
        }
    
        // Calculate padding at the beginning based on current offset.
        const VkDeviceSize paddingBegin = *pOffset - suballocItem->offset;

        // Calculate required margin at the end.
        const VkDeviceSize requiredEndMargin = VMA_DEBUG_MARGIN;

        const VkDeviceSize totalSize = paddingBegin + allocSize + requiredEndMargin;
        // Another early return check.
        if(suballocItem->offset + totalSize > GetSize())
        {
            return false;
        }

        // Advance lastSuballocItem until desired size is reached.
        // Update itemsToMakeLostCount.
        VmaSuballocationList::const_iterator lastSuballocItem = suballocItem;
        if(totalSize > suballocItem->size)
        {
            VkDeviceSize remainingSize = totalSize - suballocItem->size;
            while(remainingSize > 0)
            {
                ++lastSuballocItem;
                if(lastSuballocItem == m_Suballocations.cend())
                {
                    return false;
                }
                if(lastSuballocItem->type == VMA_SUBALLOCATION_TYPE_FREE)
                {
                    *pSumFreeSize += lastSuballocItem->size;
                }
                else
                {
                    VMA_ASSERT(lastSuballocItem->hAllocation != VK_NULL_HANDLE);
                    if(lastSuballocItem->hAllocation->CanBecomeLost() &&
                        lastSuballocItem->hAllocation->GetLastUseFrameIndex() + frameInUseCount < currentFrameIndex)
                    {
                        ++*itemsToMakeLostCount;
                        *pSumItemSize += lastSuballocItem->size;
                    }
                    else
                    {
                        return false;
                    }
                }
                remainingSize = (lastSuballocItem->size < remainingSize) ?
                    remainingSize - lastSuballocItem->size : 0;
            }
        }

        // Check next suballocations for BufferImageGranularity conflicts.
        // If conflict exists, we must mark more allocations lost or fail.
        if(bufferImageGranularity > 1)
        {
            VmaSuballocationList::const_iterator nextSuballocItem = lastSuballocItem;
            ++nextSuballocItem;
            while(nextSuballocItem != m_Suballocations.cend())
            {
                const VmaSuballocation& nextSuballoc = *nextSuballocItem;
                if(VmaBlocksOnSamePage(*pOffset, allocSize, nextSuballoc.offset, bufferImageGranularity))
                {
                    if(VmaIsBufferImageGranularityConflict(allocType, nextSuballoc.type))
                    {
                        VMA_ASSERT(nextSuballoc.hAllocation != VK_NULL_HANDLE);
                        if(nextSuballoc.hAllocation->CanBecomeLost() &&
                            nextSuballoc.hAllocation->GetLastUseFrameIndex() + frameInUseCount < currentFrameIndex)
                        {
                            ++*itemsToMakeLostCount;
                        }
                        else
                        {
                            return false;
                        }
                    }
                }
                else
                {
                    // Already on next page.
                    break;
                }
                ++nextSuballocItem;
            }
        }
    }
    else
    {
        const VmaSuballocation& suballoc = *suballocItem;
        VMA_ASSERT(suballoc.type == VMA_SUBALLOCATION_TYPE_FREE);

        *pSumFreeSize = suballoc.size;

        // Size of this suballocation is too small for this request: Early return.
        if(suballoc.size < allocSize)
        {
            return false;
        }

        // Start from offset equal to beginning of this suballocation.
        *pOffset = suballoc.offset;
    
        // Apply VMA_DEBUG_MARGIN at the beginning.
        if(VMA_DEBUG_MARGIN > 0)
        {
            *pOffset += VMA_DEBUG_MARGIN;
        }
    
        // Apply alignment.
        *pOffset = VmaAlignUp(*pOffset, allocAlignment);
    
        // Check previous suballocations for BufferImageGranularity conflicts.
        // Make bigger alignment if necessary.
        if(bufferImageGranularity > 1)
        {
            bool bufferImageGranularityConflict = false;
            VmaSuballocationList::const_iterator prevSuballocItem = suballocItem;
            while(prevSuballocItem != m_Suballocations.cbegin())
            {
                --prevSuballocItem;
                const VmaSuballocation& prevSuballoc = *prevSuballocItem;
                if(VmaBlocksOnSamePage(prevSuballoc.offset, prevSuballoc.size, *pOffset, bufferImageGranularity))
                {
                    if(VmaIsBufferImageGranularityConflict(prevSuballoc.type, allocType))
                    {
                        bufferImageGranularityConflict = true;
                        break;
                    }
                }
                else
                    // Already on previous page.
                    break;
            }
            if(bufferImageGranularityConflict)
            {
                *pOffset = VmaAlignUp(*pOffset, bufferImageGranularity);
            }
        }
    
        // Calculate padding at the beginning based on current offset.
        const VkDeviceSize paddingBegin = *pOffset - suballoc.offset;

        // Calculate required margin at the end.
        const VkDeviceSize requiredEndMargin = VMA_DEBUG_MARGIN;

        // Fail if requested size plus margin before and after is bigger than size of this suballocation.
        if(paddingBegin + allocSize + requiredEndMargin > suballoc.size)
        {
            return false;
        }

        // Check next suballocations for BufferImageGranularity conflicts.
        // If conflict exists, allocation cannot be made here.
        if(bufferImageGranularity > 1)
        {
            VmaSuballocationList::const_iterator nextSuballocItem = suballocItem;
            ++nextSuballocItem;
            while(nextSuballocItem != m_Suballocations.cend())
            {
                const VmaSuballocation& nextSuballoc = *nextSuballocItem;
                if(VmaBlocksOnSamePage(*pOffset, allocSize, nextSuballoc.offset, bufferImageGranularity))
                {
                    if(VmaIsBufferImageGranularityConflict(allocType, nextSuballoc.type))
                    {
                        return false;
                    }
                }
                else
                {
                    // Already on next page.
                    break;
                }
                ++nextSuballocItem;
            }
        }
    }

    // All tests passed: Success. pOffset is already filled.
    return true;
}

void VmaBlockMetadata_Generic::MergeFreeWithNext(VmaSuballocationList::iterator item)
{
    VMA_ASSERT(item != m_Suballocations.end());
    VMA_ASSERT(item->type == VMA_SUBALLOCATION_TYPE_FREE);
    
    VmaSuballocationList::iterator nextItem = item;
    ++nextItem;
    VMA_ASSERT(nextItem != m_Suballocations.end());
    VMA_ASSERT(nextItem->type == VMA_SUBALLOCATION_TYPE_FREE);

    item->size += nextItem->size;
    --m_FreeCount;
    m_Suballocations.erase(nextItem);
}

VmaSuballocationList::iterator VmaBlockMetadata_Generic::FreeSuballocation(VmaSuballocationList::iterator suballocItem)
{
    // Change this suballocation to be marked as free.
    VmaSuballocation& suballoc = *suballocItem;
    suballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
    suballoc.hAllocation = VK_NULL_HANDLE;
    
    // Update totals.
    ++m_FreeCount;
    m_SumFreeSize += suballoc.size;

    // Merge with previous and/or next suballocation if it's also free.
    bool mergeWithNext = false;
    bool mergeWithPrev = false;
    
    VmaSuballocationList::iterator nextItem = suballocItem;
    ++nextItem;
    if((nextItem != m_Suballocations.end()) && (nextItem->type == VMA_SUBALLOCATION_TYPE_FREE))
    {
        mergeWithNext = true;
    }

    VmaSuballocationList::iterator prevItem = suballocItem;
    if(suballocItem != m_Suballocations.begin())
    {
        --prevItem;
        if(prevItem->type == VMA_SUBALLOCATION_TYPE_FREE)
        {
            mergeWithPrev = true;
        }
    }

    if(mergeWithNext)
    {
        UnregisterFreeSuballocation(nextItem);
        MergeFreeWithNext(suballocItem);
    }

    if(mergeWithPrev)
    {
        UnregisterFreeSuballocation(prevItem);
        MergeFreeWithNext(prevItem);
        RegisterFreeSuballocation(prevItem);
        return prevItem;
    }
    else
    {
        RegisterFreeSuballocation(suballocItem);
        return suballocItem;
    }
}

void VmaBlockMetadata_Generic::RegisterFreeSuballocation(VmaSuballocationList::iterator item)
{
    VMA_ASSERT(item->type == VMA_SUBALLOCATION_TYPE_FREE);
    VMA_ASSERT(item->size > 0);

    // You may want to enable this validation at the beginning or at the end of
    // this function, depending on what do you want to check.
    VMA_HEAVY_ASSERT(ValidateFreeSuballocationList());

    if(item->size >= VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER)
    {
        if(m_FreeSuballocationsBySize.empty())
        {
            m_FreeSuballocationsBySize.push_back(item);
        }
        else
        {
            VmaVectorInsertSorted<VmaSuballocationItemSizeLess>(m_FreeSuballocationsBySize, item);
        }
    }

    //VMA_HEAVY_ASSERT(ValidateFreeSuballocationList());
}


void VmaBlockMetadata_Generic::UnregisterFreeSuballocation(VmaSuballocationList::iterator item)
{
    VMA_ASSERT(item->type == VMA_SUBALLOCATION_TYPE_FREE);
    VMA_ASSERT(item->size > 0);

    // You may want to enable this validation at the beginning or at the end of
    // this function, depending on what do you want to check.
    VMA_HEAVY_ASSERT(ValidateFreeSuballocationList());

    if(item->size >= VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER)
    {
        VmaSuballocationList::iterator* const it = VmaBinaryFindFirstNotLess(
            m_FreeSuballocationsBySize.data(),
            m_FreeSuballocationsBySize.data() + m_FreeSuballocationsBySize.size(),
            item,
            VmaSuballocationItemSizeLess());
        for(size_t index = it - m_FreeSuballocationsBySize.data();
            index < m_FreeSuballocationsBySize.size();
            ++index)
        {
            if(m_FreeSuballocationsBySize[index] == item)
            {
                VmaVectorRemove(m_FreeSuballocationsBySize, index);
                return;
            }
            VMA_ASSERT((m_FreeSuballocationsBySize[index]->size == item->size) && "Not found.");
        }
        VMA_ASSERT(0 && "Not found.");
    }

    //VMA_HEAVY_ASSERT(ValidateFreeSuballocationList());
}

bool VmaBlockMetadata_Generic::IsBufferImageGranularityConflictPossible(
    VkDeviceSize bufferImageGranularity,
    VmaSuballocationType& inOutPrevSuballocType) const
{
    if(bufferImageGranularity == 1 || IsEmpty())
    {
        return false;
    }

    VkDeviceSize minAlignment = VK_WHOLE_SIZE;
    bool typeConflictFound = false;
    for(VmaSuballocationList::const_iterator it = m_Suballocations.cbegin();
        it != m_Suballocations.cend();
        ++it)
    {
        const VmaSuballocationType suballocType = it->type;
        if(suballocType != VMA_SUBALLOCATION_TYPE_FREE)
        {
            minAlignment = VMA_MIN(minAlignment, it->hAllocation->GetAlignment());
            if(VmaIsBufferImageGranularityConflict(inOutPrevSuballocType, suballocType))
            {
                typeConflictFound = true;
            }
            inOutPrevSuballocType = suballocType;
        }
    }

    return typeConflictFound || minAlignment >= bufferImageGranularity;
}

// class VmaBlockMetadata_Linear

VmaBlockMetadata_Linear::VmaBlockMetadata_Linear(VmaAllocator hAllocator) :
    VmaBlockMetadata(hAllocator),
    m_SumFreeSize(0),
    m_Suballocations0(VmaStlAllocator<VmaSuballocation>(hAllocator->GetAllocationCallbacks())),
    m_Suballocations1(VmaStlAllocator<VmaSuballocation>(hAllocator->GetAllocationCallbacks())),
    m_1stVectorIndex(0),
    m_2ndVectorMode(SECOND_VECTOR_EMPTY),
    m_1stNullItemsBeginCount(0),
    m_1stNullItemsMiddleCount(0),
    m_2ndNullItemsCount(0)
{
}

VmaBlockMetadata_Linear::~VmaBlockMetadata_Linear()
{
}

void VmaBlockMetadata_Linear::Init(VkDeviceSize size)
{
    VmaBlockMetadata::Init(size);
    m_SumFreeSize = size;
}

bool VmaBlockMetadata_Linear::Validate() const
{
    const SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    const SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();

    VMA_VALIDATE(suballocations2nd.empty() == (m_2ndVectorMode == SECOND_VECTOR_EMPTY));
    VMA_VALIDATE(!suballocations1st.empty() ||
        suballocations2nd.empty() ||
        m_2ndVectorMode != SECOND_VECTOR_RING_BUFFER);

    if(!suballocations1st.empty())
    {
        // Null item at the beginning should be accounted into m_1stNullItemsBeginCount.
        VMA_VALIDATE(suballocations1st[m_1stNullItemsBeginCount].hAllocation != VK_NULL_HANDLE);
        // Null item at the end should be just pop_back().
        VMA_VALIDATE(suballocations1st.back().hAllocation != VK_NULL_HANDLE);
    }
    if(!suballocations2nd.empty())
    {
        // Null item at the end should be just pop_back().
        VMA_VALIDATE(suballocations2nd.back().hAllocation != VK_NULL_HANDLE);
    }

    VMA_VALIDATE(m_1stNullItemsBeginCount + m_1stNullItemsMiddleCount <= suballocations1st.size());
    VMA_VALIDATE(m_2ndNullItemsCount <= suballocations2nd.size());

    VkDeviceSize sumUsedSize = 0;
    const size_t suballoc1stCount = suballocations1st.size();
    VkDeviceSize offset = VMA_DEBUG_MARGIN;

    if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
    {
        const size_t suballoc2ndCount = suballocations2nd.size();
        size_t nullItem2ndCount = 0;
        for(size_t i = 0; i < suballoc2ndCount; ++i)
        {
            const VmaSuballocation& suballoc = suballocations2nd[i];
            const bool currFree = (suballoc.type == VMA_SUBALLOCATION_TYPE_FREE);

            VMA_VALIDATE(currFree == (suballoc.hAllocation == VK_NULL_HANDLE));
            VMA_VALIDATE(suballoc.offset >= offset);

            if(!currFree)
            {
                VMA_VALIDATE(suballoc.hAllocation->GetOffset() == suballoc.offset);
                VMA_VALIDATE(suballoc.hAllocation->GetSize() == suballoc.size);
                sumUsedSize += suballoc.size;
            }
            else
            {
                ++nullItem2ndCount;
            }

            offset = suballoc.offset + suballoc.size + VMA_DEBUG_MARGIN;
        }

        VMA_VALIDATE(nullItem2ndCount == m_2ndNullItemsCount);
    }

    for(size_t i = 0; i < m_1stNullItemsBeginCount; ++i)
    {
        const VmaSuballocation& suballoc = suballocations1st[i];
        VMA_VALIDATE(suballoc.type == VMA_SUBALLOCATION_TYPE_FREE &&
            suballoc.hAllocation == VK_NULL_HANDLE);
    }

    size_t nullItem1stCount = m_1stNullItemsBeginCount;

    for(size_t i = m_1stNullItemsBeginCount; i < suballoc1stCount; ++i)
    {
        const VmaSuballocation& suballoc = suballocations1st[i];
        const bool currFree = (suballoc.type == VMA_SUBALLOCATION_TYPE_FREE);

        VMA_VALIDATE(currFree == (suballoc.hAllocation == VK_NULL_HANDLE));
        VMA_VALIDATE(suballoc.offset >= offset);
        VMA_VALIDATE(i >= m_1stNullItemsBeginCount || currFree);

        if(!currFree)
        {
            VMA_VALIDATE(suballoc.hAllocation->GetOffset() == suballoc.offset);
            VMA_VALIDATE(suballoc.hAllocation->GetSize() == suballoc.size);
            sumUsedSize += suballoc.size;
        }
        else
        {
            ++nullItem1stCount;
        }

        offset = suballoc.offset + suballoc.size + VMA_DEBUG_MARGIN;
    }
    VMA_VALIDATE(nullItem1stCount == m_1stNullItemsBeginCount + m_1stNullItemsMiddleCount);

    if(m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
    {
        const size_t suballoc2ndCount = suballocations2nd.size();
        size_t nullItem2ndCount = 0;
        for(size_t i = suballoc2ndCount; i--; )
        {
            const VmaSuballocation& suballoc = suballocations2nd[i];
            const bool currFree = (suballoc.type == VMA_SUBALLOCATION_TYPE_FREE);

            VMA_VALIDATE(currFree == (suballoc.hAllocation == VK_NULL_HANDLE));
            VMA_VALIDATE(suballoc.offset >= offset);

            if(!currFree)
            {
                VMA_VALIDATE(suballoc.hAllocation->GetOffset() == suballoc.offset);
                VMA_VALIDATE(suballoc.hAllocation->GetSize() == suballoc.size);
                sumUsedSize += suballoc.size;
            }
            else
            {
                ++nullItem2ndCount;
            }

            offset = suballoc.offset + suballoc.size + VMA_DEBUG_MARGIN;
        }

        VMA_VALIDATE(nullItem2ndCount == m_2ndNullItemsCount);
    }

    VMA_VALIDATE(offset <= GetSize());
    VMA_VALIDATE(m_SumFreeSize == GetSize() - sumUsedSize);

    return true;
}

size_t VmaBlockMetadata_Linear::GetAllocationCount() const
{
    return AccessSuballocations1st().size() - (m_1stNullItemsBeginCount + m_1stNullItemsMiddleCount) +
        AccessSuballocations2nd().size() - m_2ndNullItemsCount;
}

VkDeviceSize VmaBlockMetadata_Linear::GetUnusedRangeSizeMax() const
{
    const VkDeviceSize size = GetSize();

    /*
    We don't consider gaps inside allocation vectors with freed allocations because
    they are not suitable for reuse in linear allocator. We consider only space that
    is available for new allocations.
    */
    if(IsEmpty())
    {
        return size;
    }
    
    const SuballocationVectorType& suballocations1st = AccessSuballocations1st();

    switch(m_2ndVectorMode)
    {
    case SECOND_VECTOR_EMPTY:
        /*
        Available space is after end of 1st, as well as before beginning of 1st (which
        whould make it a ring buffer).
        */
        {
            const size_t suballocations1stCount = suballocations1st.size();
            VMA_ASSERT(suballocations1stCount > m_1stNullItemsBeginCount);
            const VmaSuballocation& firstSuballoc = suballocations1st[m_1stNullItemsBeginCount];
            const VmaSuballocation& lastSuballoc  = suballocations1st[suballocations1stCount - 1];
            return VMA_MAX(
                firstSuballoc.offset,
                size - (lastSuballoc.offset + lastSuballoc.size));
        }
        break;

    case SECOND_VECTOR_RING_BUFFER:
        /*
        Available space is only between end of 2nd and beginning of 1st.
        */
        {
            const SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
            const VmaSuballocation& lastSuballoc2nd = suballocations2nd.back();
            const VmaSuballocation& firstSuballoc1st = suballocations1st[m_1stNullItemsBeginCount];
            return firstSuballoc1st.offset - (lastSuballoc2nd.offset + lastSuballoc2nd.size);
        }
        break;

    case SECOND_VECTOR_DOUBLE_STACK:
        /*
        Available space is only between end of 1st and top of 2nd.
        */
        {
            const SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
            const VmaSuballocation& topSuballoc2nd = suballocations2nd.back();
            const VmaSuballocation& lastSuballoc1st = suballocations1st.back();
            return topSuballoc2nd.offset - (lastSuballoc1st.offset + lastSuballoc1st.size);
        }
        break;

    default:
        VMA_ASSERT(0);
        return 0;
    }
}

void VmaBlockMetadata_Linear::CalcAllocationStatInfo(VmaStatInfo& outInfo) const
{
    const VkDeviceSize size = GetSize();
    const SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    const SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
    const size_t suballoc1stCount = suballocations1st.size();
    const size_t suballoc2ndCount = suballocations2nd.size();

    outInfo.blockCount = 1;
    outInfo.allocationCount = (uint32_t)GetAllocationCount();
    outInfo.unusedRangeCount = 0;
    outInfo.usedBytes = 0;
    outInfo.allocationSizeMin = UINT64_MAX;
    outInfo.allocationSizeMax = 0;
    outInfo.unusedRangeSizeMin = UINT64_MAX;
    outInfo.unusedRangeSizeMax = 0;

    VkDeviceSize lastOffset = 0;

    if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
    {
        const VkDeviceSize freeSpace2ndTo1stEnd = suballocations1st[m_1stNullItemsBeginCount].offset;
        size_t nextAlloc2ndIndex = 0;
        while(lastOffset < freeSpace2ndTo1stEnd)
        {
            // Find next non-null allocation or move nextAllocIndex to the end.
            while(nextAlloc2ndIndex < suballoc2ndCount &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                ++nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex < suballoc2ndCount)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                    ++outInfo.unusedRangeCount;
                    outInfo.unusedBytes += unusedRangeSize;
                    outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, unusedRangeSize);
                    outInfo.unusedRangeSizeMax = VMA_MIN(outInfo.unusedRangeSizeMax, unusedRangeSize);
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                outInfo.usedBytes += suballoc.size;
                outInfo.allocationSizeMin = VMA_MIN(outInfo.allocationSizeMin, suballoc.size);
                outInfo.allocationSizeMax = VMA_MIN(outInfo.allocationSizeMax, suballoc.size);
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                ++nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                // There is free space from lastOffset to freeSpace2ndTo1stEnd.
                if(lastOffset < freeSpace2ndTo1stEnd)
                {
                    const VkDeviceSize unusedRangeSize = freeSpace2ndTo1stEnd - lastOffset;
                    ++outInfo.unusedRangeCount;
                    outInfo.unusedBytes += unusedRangeSize;
                    outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, unusedRangeSize);
                    outInfo.unusedRangeSizeMax = VMA_MIN(outInfo.unusedRangeSizeMax, unusedRangeSize);
               }

                // End of loop.
                lastOffset = freeSpace2ndTo1stEnd;
            }
        }
    }

    size_t nextAlloc1stIndex = m_1stNullItemsBeginCount;
    const VkDeviceSize freeSpace1stTo2ndEnd =
        m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK ? suballocations2nd.back().offset : size;
    while(lastOffset < freeSpace1stTo2ndEnd)
    {
        // Find next non-null allocation or move nextAllocIndex to the end.
        while(nextAlloc1stIndex < suballoc1stCount &&
            suballocations1st[nextAlloc1stIndex].hAllocation == VK_NULL_HANDLE)
        {
            ++nextAlloc1stIndex;
        }

        // Found non-null allocation.
        if(nextAlloc1stIndex < suballoc1stCount)
        {
            const VmaSuballocation& suballoc = suballocations1st[nextAlloc1stIndex];
            
            // 1. Process free space before this allocation.
            if(lastOffset < suballoc.offset)
            {
                // There is free space from lastOffset to suballoc.offset.
                const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                ++outInfo.unusedRangeCount;
                outInfo.unusedBytes += unusedRangeSize;
                outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, unusedRangeSize);
                outInfo.unusedRangeSizeMax = VMA_MIN(outInfo.unusedRangeSizeMax, unusedRangeSize);
            }
            
            // 2. Process this allocation.
            // There is allocation with suballoc.offset, suballoc.size.
            outInfo.usedBytes += suballoc.size;
            outInfo.allocationSizeMin = VMA_MIN(outInfo.allocationSizeMin, suballoc.size);
            outInfo.allocationSizeMax = VMA_MIN(outInfo.allocationSizeMax, suballoc.size);
            
            // 3. Prepare for next iteration.
            lastOffset = suballoc.offset + suballoc.size;
            ++nextAlloc1stIndex;
        }
        // We are at the end.
        else
        {
            // There is free space from lastOffset to freeSpace1stTo2ndEnd.
            if(lastOffset < freeSpace1stTo2ndEnd)
            {
                const VkDeviceSize unusedRangeSize = freeSpace1stTo2ndEnd - lastOffset;
                ++outInfo.unusedRangeCount;
                outInfo.unusedBytes += unusedRangeSize;
                outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, unusedRangeSize);
                outInfo.unusedRangeSizeMax = VMA_MIN(outInfo.unusedRangeSizeMax, unusedRangeSize);
           }

            // End of loop.
            lastOffset = freeSpace1stTo2ndEnd;
        }
    }

    if(m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
    {
        size_t nextAlloc2ndIndex = suballocations2nd.size() - 1;
        while(lastOffset < size)
        {
            // Find next non-null allocation or move nextAllocIndex to the end.
            while(nextAlloc2ndIndex != SIZE_MAX &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                --nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex != SIZE_MAX)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                    ++outInfo.unusedRangeCount;
                    outInfo.unusedBytes += unusedRangeSize;
                    outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, unusedRangeSize);
                    outInfo.unusedRangeSizeMax = VMA_MIN(outInfo.unusedRangeSizeMax, unusedRangeSize);
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                outInfo.usedBytes += suballoc.size;
                outInfo.allocationSizeMin = VMA_MIN(outInfo.allocationSizeMin, suballoc.size);
                outInfo.allocationSizeMax = VMA_MIN(outInfo.allocationSizeMax, suballoc.size);
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                --nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                // There is free space from lastOffset to size.
                if(lastOffset < size)
                {
                    const VkDeviceSize unusedRangeSize = size - lastOffset;
                    ++outInfo.unusedRangeCount;
                    outInfo.unusedBytes += unusedRangeSize;
                    outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, unusedRangeSize);
                    outInfo.unusedRangeSizeMax = VMA_MIN(outInfo.unusedRangeSizeMax, unusedRangeSize);
               }

                // End of loop.
                lastOffset = size;
            }
        }
    }

    outInfo.unusedBytes = size - outInfo.usedBytes;
}

void VmaBlockMetadata_Linear::AddPoolStats(VmaPoolStats& inoutStats) const
{
    const SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    const SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
    const VkDeviceSize size = GetSize();
    const size_t suballoc1stCount = suballocations1st.size();
    const size_t suballoc2ndCount = suballocations2nd.size();

    inoutStats.size += size;

    VkDeviceSize lastOffset = 0;

    if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
    {
        const VkDeviceSize freeSpace2ndTo1stEnd = suballocations1st[m_1stNullItemsBeginCount].offset;
        size_t nextAlloc2ndIndex = m_1stNullItemsBeginCount;
        while(lastOffset < freeSpace2ndTo1stEnd)
        {
            // Find next non-null allocation or move nextAlloc2ndIndex to the end.
            while(nextAlloc2ndIndex < suballoc2ndCount &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                ++nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex < suballoc2ndCount)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                    inoutStats.unusedSize += unusedRangeSize;
                    ++inoutStats.unusedRangeCount;
                    inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, unusedRangeSize);
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                ++inoutStats.allocationCount;
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                ++nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                if(lastOffset < freeSpace2ndTo1stEnd)
                {
                    // There is free space from lastOffset to freeSpace2ndTo1stEnd.
                    const VkDeviceSize unusedRangeSize = freeSpace2ndTo1stEnd - lastOffset;
                    inoutStats.unusedSize += unusedRangeSize;
                    ++inoutStats.unusedRangeCount;
                    inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, unusedRangeSize);
                }

                // End of loop.
                lastOffset = freeSpace2ndTo1stEnd;
            }
        }
    }

    size_t nextAlloc1stIndex = m_1stNullItemsBeginCount;
    const VkDeviceSize freeSpace1stTo2ndEnd =
        m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK ? suballocations2nd.back().offset : size;
    while(lastOffset < freeSpace1stTo2ndEnd)
    {
        // Find next non-null allocation or move nextAllocIndex to the end.
        while(nextAlloc1stIndex < suballoc1stCount &&
            suballocations1st[nextAlloc1stIndex].hAllocation == VK_NULL_HANDLE)
        {
            ++nextAlloc1stIndex;
        }

        // Found non-null allocation.
        if(nextAlloc1stIndex < suballoc1stCount)
        {
            const VmaSuballocation& suballoc = suballocations1st[nextAlloc1stIndex];
            
            // 1. Process free space before this allocation.
            if(lastOffset < suballoc.offset)
            {
                // There is free space from lastOffset to suballoc.offset.
                const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                inoutStats.unusedSize += unusedRangeSize;
                ++inoutStats.unusedRangeCount;
                inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, unusedRangeSize);
            }
            
            // 2. Process this allocation.
            // There is allocation with suballoc.offset, suballoc.size.
            ++inoutStats.allocationCount;
            
            // 3. Prepare for next iteration.
            lastOffset = suballoc.offset + suballoc.size;
            ++nextAlloc1stIndex;
        }
        // We are at the end.
        else
        {
            if(lastOffset < freeSpace1stTo2ndEnd)
            {
                // There is free space from lastOffset to freeSpace1stTo2ndEnd.
                const VkDeviceSize unusedRangeSize = freeSpace1stTo2ndEnd - lastOffset;
                inoutStats.unusedSize += unusedRangeSize;
                ++inoutStats.unusedRangeCount;
                inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, unusedRangeSize);
            }

            // End of loop.
            lastOffset = freeSpace1stTo2ndEnd;
        }
    }

    if(m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
    {
        size_t nextAlloc2ndIndex = suballocations2nd.size() - 1;
        while(lastOffset < size)
        {
            // Find next non-null allocation or move nextAlloc2ndIndex to the end.
            while(nextAlloc2ndIndex != SIZE_MAX &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                --nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex != SIZE_MAX)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                    inoutStats.unusedSize += unusedRangeSize;
                    ++inoutStats.unusedRangeCount;
                    inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, unusedRangeSize);
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                ++inoutStats.allocationCount;
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                --nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                if(lastOffset < size)
                {
                    // There is free space from lastOffset to size.
                    const VkDeviceSize unusedRangeSize = size - lastOffset;
                    inoutStats.unusedSize += unusedRangeSize;
                    ++inoutStats.unusedRangeCount;
                    inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, unusedRangeSize);
                }

                // End of loop.
                lastOffset = size;
            }
        }
    }
}

#if VMA_STATS_STRING_ENABLED
void VmaBlockMetadata_Linear::PrintDetailedMap(class VmaJsonWriter& json) const
{
    const VkDeviceSize size = GetSize();
    const SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    const SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
    const size_t suballoc1stCount = suballocations1st.size();
    const size_t suballoc2ndCount = suballocations2nd.size();

    // FIRST PASS

    size_t unusedRangeCount = 0;
    VkDeviceSize usedBytes = 0;

    VkDeviceSize lastOffset = 0;

    size_t alloc2ndCount = 0;
    if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
    {
        const VkDeviceSize freeSpace2ndTo1stEnd = suballocations1st[m_1stNullItemsBeginCount].offset;
        size_t nextAlloc2ndIndex = 0;
        while(lastOffset < freeSpace2ndTo1stEnd)
        {
            // Find next non-null allocation or move nextAlloc2ndIndex to the end.
            while(nextAlloc2ndIndex < suballoc2ndCount &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                ++nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex < suballoc2ndCount)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    ++unusedRangeCount;
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                ++alloc2ndCount;
                usedBytes += suballoc.size;
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                ++nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                if(lastOffset < freeSpace2ndTo1stEnd)
                {
                    // There is free space from lastOffset to freeSpace2ndTo1stEnd.
                    ++unusedRangeCount;
                }

                // End of loop.
                lastOffset = freeSpace2ndTo1stEnd;
            }
        }
    }

    size_t nextAlloc1stIndex = m_1stNullItemsBeginCount;
    size_t alloc1stCount = 0;
    const VkDeviceSize freeSpace1stTo2ndEnd =
        m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK ? suballocations2nd.back().offset : size;
    while(lastOffset < freeSpace1stTo2ndEnd)
    {
        // Find next non-null allocation or move nextAllocIndex to the end.
        while(nextAlloc1stIndex < suballoc1stCount &&
            suballocations1st[nextAlloc1stIndex].hAllocation == VK_NULL_HANDLE)
        {
            ++nextAlloc1stIndex;
        }

        // Found non-null allocation.
        if(nextAlloc1stIndex < suballoc1stCount)
        {
            const VmaSuballocation& suballoc = suballocations1st[nextAlloc1stIndex];
            
            // 1. Process free space before this allocation.
            if(lastOffset < suballoc.offset)
            {
                // There is free space from lastOffset to suballoc.offset.
                ++unusedRangeCount;
            }
            
            // 2. Process this allocation.
            // There is allocation with suballoc.offset, suballoc.size.
            ++alloc1stCount;
            usedBytes += suballoc.size;
            
            // 3. Prepare for next iteration.
            lastOffset = suballoc.offset + suballoc.size;
            ++nextAlloc1stIndex;
        }
        // We are at the end.
        else
        {
            if(lastOffset < size)
            {
                // There is free space from lastOffset to freeSpace1stTo2ndEnd.
                ++unusedRangeCount;
            }

            // End of loop.
            lastOffset = freeSpace1stTo2ndEnd;
        }
    }

    if(m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
    {
        size_t nextAlloc2ndIndex = suballocations2nd.size() - 1;
        while(lastOffset < size)
        {
            // Find next non-null allocation or move nextAlloc2ndIndex to the end.
            while(nextAlloc2ndIndex != SIZE_MAX &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                --nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex != SIZE_MAX)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    ++unusedRangeCount;
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                ++alloc2ndCount;
                usedBytes += suballoc.size;
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                --nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                if(lastOffset < size)
                {
                    // There is free space from lastOffset to size.
                    ++unusedRangeCount;
                }

                // End of loop.
                lastOffset = size;
            }
        }
    }

    const VkDeviceSize unusedBytes = size - usedBytes;
    PrintDetailedMap_Begin(json, unusedBytes, alloc1stCount + alloc2ndCount, unusedRangeCount);

    // SECOND PASS
    lastOffset = 0;

    if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
    {
        const VkDeviceSize freeSpace2ndTo1stEnd = suballocations1st[m_1stNullItemsBeginCount].offset;
        size_t nextAlloc2ndIndex = 0;
        while(lastOffset < freeSpace2ndTo1stEnd)
        {
            // Find next non-null allocation or move nextAlloc2ndIndex to the end.
            while(nextAlloc2ndIndex < suballoc2ndCount &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                ++nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex < suballoc2ndCount)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                    PrintDetailedMap_UnusedRange(json, lastOffset, unusedRangeSize);
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                PrintDetailedMap_Allocation(json, suballoc.offset, suballoc.hAllocation);
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                ++nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                if(lastOffset < freeSpace2ndTo1stEnd)
                {
                    // There is free space from lastOffset to freeSpace2ndTo1stEnd.
                    const VkDeviceSize unusedRangeSize = freeSpace2ndTo1stEnd - lastOffset;
                    PrintDetailedMap_UnusedRange(json, lastOffset, unusedRangeSize);
                }

                // End of loop.
                lastOffset = freeSpace2ndTo1stEnd;
            }
        }
    }

    nextAlloc1stIndex = m_1stNullItemsBeginCount;
    while(lastOffset < freeSpace1stTo2ndEnd)
    {
        // Find next non-null allocation or move nextAllocIndex to the end.
        while(nextAlloc1stIndex < suballoc1stCount &&
            suballocations1st[nextAlloc1stIndex].hAllocation == VK_NULL_HANDLE)
        {
            ++nextAlloc1stIndex;
        }

        // Found non-null allocation.
        if(nextAlloc1stIndex < suballoc1stCount)
        {
            const VmaSuballocation& suballoc = suballocations1st[nextAlloc1stIndex];
            
            // 1. Process free space before this allocation.
            if(lastOffset < suballoc.offset)
            {
                // There is free space from lastOffset to suballoc.offset.
                const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                PrintDetailedMap_UnusedRange(json, lastOffset, unusedRangeSize);
            }
            
            // 2. Process this allocation.
            // There is allocation with suballoc.offset, suballoc.size.
            PrintDetailedMap_Allocation(json, suballoc.offset, suballoc.hAllocation);
            
            // 3. Prepare for next iteration.
            lastOffset = suballoc.offset + suballoc.size;
            ++nextAlloc1stIndex;
        }
        // We are at the end.
        else
        {
            if(lastOffset < freeSpace1stTo2ndEnd)
            {
                // There is free space from lastOffset to freeSpace1stTo2ndEnd.
                const VkDeviceSize unusedRangeSize = freeSpace1stTo2ndEnd - lastOffset;
                PrintDetailedMap_UnusedRange(json, lastOffset, unusedRangeSize);
            }

            // End of loop.
            lastOffset = freeSpace1stTo2ndEnd;
        }
    }

    if(m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
    {
        size_t nextAlloc2ndIndex = suballocations2nd.size() - 1;
        while(lastOffset < size)
        {
            // Find next non-null allocation or move nextAlloc2ndIndex to the end.
            while(nextAlloc2ndIndex != SIZE_MAX &&
                suballocations2nd[nextAlloc2ndIndex].hAllocation == VK_NULL_HANDLE)
            {
                --nextAlloc2ndIndex;
            }

            // Found non-null allocation.
            if(nextAlloc2ndIndex != SIZE_MAX)
            {
                const VmaSuballocation& suballoc = suballocations2nd[nextAlloc2ndIndex];
            
                // 1. Process free space before this allocation.
                if(lastOffset < suballoc.offset)
                {
                    // There is free space from lastOffset to suballoc.offset.
                    const VkDeviceSize unusedRangeSize = suballoc.offset - lastOffset;
                    PrintDetailedMap_UnusedRange(json, lastOffset, unusedRangeSize);
                }
            
                // 2. Process this allocation.
                // There is allocation with suballoc.offset, suballoc.size.
                PrintDetailedMap_Allocation(json, suballoc.offset, suballoc.hAllocation);
            
                // 3. Prepare for next iteration.
                lastOffset = suballoc.offset + suballoc.size;
                --nextAlloc2ndIndex;
            }
            // We are at the end.
            else
            {
                if(lastOffset < size)
                {
                    // There is free space from lastOffset to size.
                    const VkDeviceSize unusedRangeSize = size - lastOffset;
                    PrintDetailedMap_UnusedRange(json, lastOffset, unusedRangeSize);
                }

                // End of loop.
                lastOffset = size;
            }
        }
    }

    PrintDetailedMap_End(json);
}
#endif // #if VMA_STATS_STRING_ENABLED

bool VmaBlockMetadata_Linear::CreateAllocationRequest(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VkDeviceSize bufferImageGranularity,
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    bool upperAddress,
    VmaSuballocationType allocType,
    bool canMakeOtherLost,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{
    VMA_ASSERT(allocSize > 0);
    VMA_ASSERT(allocType != VMA_SUBALLOCATION_TYPE_FREE);
    VMA_ASSERT(pAllocationRequest != VMA_NULL);
    VMA_HEAVY_ASSERT(Validate());
    return upperAddress ?
        CreateAllocationRequest_UpperAddress(
            currentFrameIndex, frameInUseCount, bufferImageGranularity,
            allocSize, allocAlignment, allocType, canMakeOtherLost, strategy, pAllocationRequest) :
        CreateAllocationRequest_LowerAddress(
            currentFrameIndex, frameInUseCount, bufferImageGranularity,
            allocSize, allocAlignment, allocType, canMakeOtherLost, strategy, pAllocationRequest);
}

bool VmaBlockMetadata_Linear::CreateAllocationRequest_UpperAddress(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VkDeviceSize bufferImageGranularity,
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    VmaSuballocationType allocType,
    bool canMakeOtherLost,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{
    const VkDeviceSize size = GetSize();
    SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();

    if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
    {
        VMA_ASSERT(0 && "Trying to use pool with linear algorithm as double stack, while it is already being used as ring buffer.");
        return false;
    }

    // Try to allocate before 2nd.back(), or end of block if 2nd.empty().
    if(allocSize > size)
    {
        return false;
    }
    VkDeviceSize resultBaseOffset = size - allocSize;
    if(!suballocations2nd.empty())
    {
        const VmaSuballocation& lastSuballoc = suballocations2nd.back();
        resultBaseOffset = lastSuballoc.offset - allocSize;
        if(allocSize > lastSuballoc.offset)
        {
            return false;
        }
    }

    // Start from offset equal to end of free space.
    VkDeviceSize resultOffset = resultBaseOffset;

    // Apply VMA_DEBUG_MARGIN at the end.
    if(VMA_DEBUG_MARGIN > 0)
    {
        if(resultOffset < VMA_DEBUG_MARGIN)
        {
            return false;
        }
        resultOffset -= VMA_DEBUG_MARGIN;
    }

    // Apply alignment.
    resultOffset = VmaAlignDown(resultOffset, allocAlignment);

    // Check next suballocations from 2nd for BufferImageGranularity conflicts.
    // Make bigger alignment if necessary.
    if(bufferImageGranularity > 1 && !suballocations2nd.empty())
    {
        bool bufferImageGranularityConflict = false;
        for(size_t nextSuballocIndex = suballocations2nd.size(); nextSuballocIndex--; )
        {
            const VmaSuballocation& nextSuballoc = suballocations2nd[nextSuballocIndex];
            if(VmaBlocksOnSamePage(resultOffset, allocSize, nextSuballoc.offset, bufferImageGranularity))
            {
                if(VmaIsBufferImageGranularityConflict(nextSuballoc.type, allocType))
                {
                    bufferImageGranularityConflict = true;
                    break;
                }
            }
            else
                // Already on previous page.
                break;
        }
        if(bufferImageGranularityConflict)
        {
            resultOffset = VmaAlignDown(resultOffset, bufferImageGranularity);
        }
    }

    // There is enough free space.
    const VkDeviceSize endOf1st = !suballocations1st.empty() ?
        suballocations1st.back().offset + suballocations1st.back().size :
        0;
    if(endOf1st + VMA_DEBUG_MARGIN <= resultOffset)
    {
        // Check previous suballocations for BufferImageGranularity conflicts.
        // If conflict exists, allocation cannot be made here.
        if(bufferImageGranularity > 1)
        {
            for(size_t prevSuballocIndex = suballocations1st.size(); prevSuballocIndex--; )
            {
                const VmaSuballocation& prevSuballoc = suballocations1st[prevSuballocIndex];
                if(VmaBlocksOnSamePage(prevSuballoc.offset, prevSuballoc.size, resultOffset, bufferImageGranularity))
                {
                    if(VmaIsBufferImageGranularityConflict(allocType, prevSuballoc.type))
                    {
                        return false;
                    }
                }
                else
                {
                    // Already on next page.
                    break;
                }
            }
        }

        // All tests passed: Success.
        pAllocationRequest->offset = resultOffset;
        pAllocationRequest->sumFreeSize = resultBaseOffset + allocSize - endOf1st;
        pAllocationRequest->sumItemSize = 0;
        // pAllocationRequest->item unused.
        pAllocationRequest->itemsToMakeLostCount = 0;
        pAllocationRequest->type = VmaAllocationRequestType::UpperAddress;
        return true;
    }

    return false;
}

bool VmaBlockMetadata_Linear::CreateAllocationRequest_LowerAddress(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VkDeviceSize bufferImageGranularity,
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    VmaSuballocationType allocType,
    bool canMakeOtherLost,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{
    const VkDeviceSize size = GetSize();
    SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();

    if(m_2ndVectorMode == SECOND_VECTOR_EMPTY || m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
    {
        // Try to allocate at the end of 1st vector.

        VkDeviceSize resultBaseOffset = 0;
        if(!suballocations1st.empty())
        {
            const VmaSuballocation& lastSuballoc = suballocations1st.back();
            resultBaseOffset = lastSuballoc.offset + lastSuballoc.size;
        }

        // Start from offset equal to beginning of free space.
        VkDeviceSize resultOffset = resultBaseOffset;

        // Apply VMA_DEBUG_MARGIN at the beginning.
        if(VMA_DEBUG_MARGIN > 0)
        {
            resultOffset += VMA_DEBUG_MARGIN;
        }

        // Apply alignment.
        resultOffset = VmaAlignUp(resultOffset, allocAlignment);

        // Check previous suballocations for BufferImageGranularity conflicts.
        // Make bigger alignment if necessary.
        if(bufferImageGranularity > 1 && !suballocations1st.empty())
        {
            bool bufferImageGranularityConflict = false;
            for(size_t prevSuballocIndex = suballocations1st.size(); prevSuballocIndex--; )
            {
                const VmaSuballocation& prevSuballoc = suballocations1st[prevSuballocIndex];
                if(VmaBlocksOnSamePage(prevSuballoc.offset, prevSuballoc.size, resultOffset, bufferImageGranularity))
                {
                    if(VmaIsBufferImageGranularityConflict(prevSuballoc.type, allocType))
                    {
                        bufferImageGranularityConflict = true;
                        break;
                    }
                }
                else
                    // Already on previous page.
                    break;
            }
            if(bufferImageGranularityConflict)
            {
                resultOffset = VmaAlignUp(resultOffset, bufferImageGranularity);
            }
        }

        const VkDeviceSize freeSpaceEnd = m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK ?
            suballocations2nd.back().offset : size;

        // There is enough free space at the end after alignment.
        if(resultOffset + allocSize + VMA_DEBUG_MARGIN <= freeSpaceEnd)
        {
            // Check next suballocations for BufferImageGranularity conflicts.
            // If conflict exists, allocation cannot be made here.
            if(bufferImageGranularity > 1 && m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
            {
                for(size_t nextSuballocIndex = suballocations2nd.size(); nextSuballocIndex--; )
                {
                    const VmaSuballocation& nextSuballoc = suballocations2nd[nextSuballocIndex];
                    if(VmaBlocksOnSamePage(resultOffset, allocSize, nextSuballoc.offset, bufferImageGranularity))
                    {
                        if(VmaIsBufferImageGranularityConflict(allocType, nextSuballoc.type))
                        {
                            return false;
                        }
                    }
                    else
                    {
                        // Already on previous page.
                        break;
                    }
                }
            }

            // All tests passed: Success.
            pAllocationRequest->offset = resultOffset;
            pAllocationRequest->sumFreeSize = freeSpaceEnd - resultBaseOffset;
            pAllocationRequest->sumItemSize = 0;
            // pAllocationRequest->item, customData unused.
            pAllocationRequest->type = VmaAllocationRequestType::EndOf1st;
            pAllocationRequest->itemsToMakeLostCount = 0;
            return true;
        }
    }

    // Wrap-around to end of 2nd vector. Try to allocate there, watching for the
    // beginning of 1st vector as the end of free space.
    if(m_2ndVectorMode == SECOND_VECTOR_EMPTY || m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
    {
        VMA_ASSERT(!suballocations1st.empty());

        VkDeviceSize resultBaseOffset = 0;
        if(!suballocations2nd.empty())
        {
            const VmaSuballocation& lastSuballoc = suballocations2nd.back();
            resultBaseOffset = lastSuballoc.offset + lastSuballoc.size;
        }

        // Start from offset equal to beginning of free space.
        VkDeviceSize resultOffset = resultBaseOffset;

        // Apply VMA_DEBUG_MARGIN at the beginning.
        if(VMA_DEBUG_MARGIN > 0)
        {
            resultOffset += VMA_DEBUG_MARGIN;
        }

        // Apply alignment.
        resultOffset = VmaAlignUp(resultOffset, allocAlignment);

        // Check previous suballocations for BufferImageGranularity conflicts.
        // Make bigger alignment if necessary.
        if(bufferImageGranularity > 1 && !suballocations2nd.empty())
        {
            bool bufferImageGranularityConflict = false;
            for(size_t prevSuballocIndex = suballocations2nd.size(); prevSuballocIndex--; )
            {
                const VmaSuballocation& prevSuballoc = suballocations2nd[prevSuballocIndex];
                if(VmaBlocksOnSamePage(prevSuballoc.offset, prevSuballoc.size, resultOffset, bufferImageGranularity))
                {
                    if(VmaIsBufferImageGranularityConflict(prevSuballoc.type, allocType))
                    {
                        bufferImageGranularityConflict = true;
                        break;
                    }
                }
                else
                    // Already on previous page.
                    break;
            }
            if(bufferImageGranularityConflict)
            {
                resultOffset = VmaAlignUp(resultOffset, bufferImageGranularity);
            }
        }

        pAllocationRequest->itemsToMakeLostCount = 0;
        pAllocationRequest->sumItemSize = 0;
        size_t index1st = m_1stNullItemsBeginCount;

        if(canMakeOtherLost)
        {
            while(index1st < suballocations1st.size() &&
                resultOffset + allocSize + VMA_DEBUG_MARGIN > suballocations1st[index1st].offset)
            {
                // Next colliding allocation at the beginning of 1st vector found. Try to make it lost.
                const VmaSuballocation& suballoc = suballocations1st[index1st];
                if(suballoc.type == VMA_SUBALLOCATION_TYPE_FREE)
                {
                    // No problem.
                }
                else
                {
                    VMA_ASSERT(suballoc.hAllocation != VK_NULL_HANDLE);
                    if(suballoc.hAllocation->CanBecomeLost() &&
                        suballoc.hAllocation->GetLastUseFrameIndex() + frameInUseCount < currentFrameIndex)
                    {
                        ++pAllocationRequest->itemsToMakeLostCount;
                        pAllocationRequest->sumItemSize += suballoc.size;
                    }
                    else
                    {
                        return false;
                    }
                }
                ++index1st;
            }

            // Check next suballocations for BufferImageGranularity conflicts.
            // If conflict exists, we must mark more allocations lost or fail.
            if(bufferImageGranularity > 1)
            {
                while(index1st < suballocations1st.size())
                {
                    const VmaSuballocation& suballoc = suballocations1st[index1st];
                    if(VmaBlocksOnSamePage(resultOffset, allocSize, suballoc.offset, bufferImageGranularity))
                    {
                        if(suballoc.hAllocation != VK_NULL_HANDLE)
                        {
                            // Not checking actual VmaIsBufferImageGranularityConflict(allocType, suballoc.type).
                            if(suballoc.hAllocation->CanBecomeLost() &&
                                suballoc.hAllocation->GetLastUseFrameIndex() + frameInUseCount < currentFrameIndex)
                            {
                                ++pAllocationRequest->itemsToMakeLostCount;
                                pAllocationRequest->sumItemSize += suballoc.size;
                            }
                            else
                            {
                                return false;
                            }
                        }
                    }
                    else
                    {
                        // Already on next page.
                        break;
                    }
                    ++index1st;
                }
            }

            // Special case: There is not enough room at the end for this allocation, even after making all from the 1st lost.
            if(index1st == suballocations1st.size() &&
                resultOffset + allocSize + VMA_DEBUG_MARGIN > size)
            {
                // TODO: This is a known bug that it's not yet implemented and the allocation is failing.
                VMA_DEBUG_LOG("Unsupported special case in custom pool with linear allocation algorithm used as ring buffer with allocations that can be lost.");
            }
        }

        // There is enough free space at the end after alignment.
        if((index1st == suballocations1st.size() && resultOffset + allocSize + VMA_DEBUG_MARGIN <= size) ||
            (index1st < suballocations1st.size() && resultOffset + allocSize + VMA_DEBUG_MARGIN <= suballocations1st[index1st].offset))
        {
            // Check next suballocations for BufferImageGranularity conflicts.
            // If conflict exists, allocation cannot be made here.
            if(bufferImageGranularity > 1)
            {
                for(size_t nextSuballocIndex = index1st;
                    nextSuballocIndex < suballocations1st.size();
                    nextSuballocIndex++)
                {
                    const VmaSuballocation& nextSuballoc = suballocations1st[nextSuballocIndex];
                    if(VmaBlocksOnSamePage(resultOffset, allocSize, nextSuballoc.offset, bufferImageGranularity))
                    {
                        if(VmaIsBufferImageGranularityConflict(allocType, nextSuballoc.type))
                        {
                            return false;
                        }
                    }
                    else
                    {
                        // Already on next page.
                        break;
                    }
                }
            }

            // All tests passed: Success.
            pAllocationRequest->offset = resultOffset;
            pAllocationRequest->sumFreeSize =
                (index1st < suballocations1st.size() ? suballocations1st[index1st].offset : size)
                - resultBaseOffset
                - pAllocationRequest->sumItemSize;
            pAllocationRequest->type = VmaAllocationRequestType::EndOf2nd;
            // pAllocationRequest->item, customData unused.
            return true;
        }
    }

    return false;
}

bool VmaBlockMetadata_Linear::MakeRequestedAllocationsLost(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VmaAllocationRequest* pAllocationRequest)
{
    if(pAllocationRequest->itemsToMakeLostCount == 0)
    {
        return true;
    }

    VMA_ASSERT(m_2ndVectorMode == SECOND_VECTOR_EMPTY || m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER);
    
    // We always start from 1st.
    SuballocationVectorType* suballocations = &AccessSuballocations1st();
    size_t index = m_1stNullItemsBeginCount;
    size_t madeLostCount = 0;
    while(madeLostCount < pAllocationRequest->itemsToMakeLostCount)
    {
        if(index == suballocations->size())
        {
            index = 0;
            // If we get to the end of 1st, we wrap around to beginning of 2nd of 1st.
            if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
            {
                suballocations = &AccessSuballocations2nd();
            }
            // else: m_2ndVectorMode == SECOND_VECTOR_EMPTY:
            // suballocations continues pointing at AccessSuballocations1st().
            VMA_ASSERT(!suballocations->empty());
        }
        VmaSuballocation& suballoc = (*suballocations)[index];
        if(suballoc.type != VMA_SUBALLOCATION_TYPE_FREE)
        {
            VMA_ASSERT(suballoc.hAllocation != VK_NULL_HANDLE);
            VMA_ASSERT(suballoc.hAllocation->CanBecomeLost());
            if(suballoc.hAllocation->MakeLost(currentFrameIndex, frameInUseCount))
            {
                suballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
                suballoc.hAllocation = VK_NULL_HANDLE;
                m_SumFreeSize += suballoc.size;
                if(suballocations == &AccessSuballocations1st())
                {
                    ++m_1stNullItemsMiddleCount;
                }
                else
                {
                    ++m_2ndNullItemsCount;
                }
                ++madeLostCount;
            }
            else
            {
                return false;
            }
        }
        ++index;
    }

    CleanupAfterFree();
    //VMA_HEAVY_ASSERT(Validate()); // Already called by ClanupAfterFree().
    
    return true;
}

uint32_t VmaBlockMetadata_Linear::MakeAllocationsLost(uint32_t currentFrameIndex, uint32_t frameInUseCount)
{
    uint32_t lostAllocationCount = 0;
    
    SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    for(size_t i = m_1stNullItemsBeginCount, count = suballocations1st.size(); i < count; ++i)
    {
        VmaSuballocation& suballoc = suballocations1st[i];
        if(suballoc.type != VMA_SUBALLOCATION_TYPE_FREE &&
            suballoc.hAllocation->CanBecomeLost() &&
            suballoc.hAllocation->MakeLost(currentFrameIndex, frameInUseCount))
        {
            suballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
            suballoc.hAllocation = VK_NULL_HANDLE;
            ++m_1stNullItemsMiddleCount;
            m_SumFreeSize += suballoc.size;
            ++lostAllocationCount;
        }
    }

    SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
    for(size_t i = 0, count = suballocations2nd.size(); i < count; ++i)
    {
        VmaSuballocation& suballoc = suballocations2nd[i];
        if(suballoc.type != VMA_SUBALLOCATION_TYPE_FREE &&
            suballoc.hAllocation->CanBecomeLost() &&
            suballoc.hAllocation->MakeLost(currentFrameIndex, frameInUseCount))
        {
            suballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
            suballoc.hAllocation = VK_NULL_HANDLE;
            ++m_2ndNullItemsCount;
            m_SumFreeSize += suballoc.size;
            ++lostAllocationCount;
        }
    }

    if(lostAllocationCount)
    {
        CleanupAfterFree();
    }

    return lostAllocationCount;
}

VkResult VmaBlockMetadata_Linear::CheckCorruption(const void* pBlockData)
{
    SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    for(size_t i = m_1stNullItemsBeginCount, count = suballocations1st.size(); i < count; ++i)
    {
        const VmaSuballocation& suballoc = suballocations1st[i];
        if(suballoc.type != VMA_SUBALLOCATION_TYPE_FREE)
        {
            if(!VmaValidateMagicValue(pBlockData, suballoc.offset - VMA_DEBUG_MARGIN))
            {
                VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED BEFORE VALIDATED ALLOCATION!");
                return VK_ERROR_VALIDATION_FAILED_EXT;
            }
            if(!VmaValidateMagicValue(pBlockData, suballoc.offset + suballoc.size))
            {
                VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED AFTER VALIDATED ALLOCATION!");
                return VK_ERROR_VALIDATION_FAILED_EXT;
            }
        }
    }

    SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
    for(size_t i = 0, count = suballocations2nd.size(); i < count; ++i)
    {
        const VmaSuballocation& suballoc = suballocations2nd[i];
        if(suballoc.type != VMA_SUBALLOCATION_TYPE_FREE)
        {
            if(!VmaValidateMagicValue(pBlockData, suballoc.offset - VMA_DEBUG_MARGIN))
            {
                VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED BEFORE VALIDATED ALLOCATION!");
                return VK_ERROR_VALIDATION_FAILED_EXT;
            }
            if(!VmaValidateMagicValue(pBlockData, suballoc.offset + suballoc.size))
            {
                VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED AFTER VALIDATED ALLOCATION!");
                return VK_ERROR_VALIDATION_FAILED_EXT;
            }
        }
    }

    return VK_SUCCESS;
}

void VmaBlockMetadata_Linear::Alloc(
    const VmaAllocationRequest& request,
    VmaSuballocationType type,
    VkDeviceSize allocSize,
    VmaAllocation hAllocation)
{
    const VmaSuballocation newSuballoc = { request.offset, allocSize, hAllocation, type };

    switch(request.type)
    {
    case VmaAllocationRequestType::UpperAddress:
        {
            VMA_ASSERT(m_2ndVectorMode != SECOND_VECTOR_RING_BUFFER &&
                "CRITICAL ERROR: Trying to use linear allocator as double stack while it was already used as ring buffer.");
            SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();
            suballocations2nd.push_back(newSuballoc);
            m_2ndVectorMode = SECOND_VECTOR_DOUBLE_STACK;
        }
        break;
    case VmaAllocationRequestType::EndOf1st:
        {
            SuballocationVectorType& suballocations1st = AccessSuballocations1st();

            VMA_ASSERT(suballocations1st.empty() ||
                request.offset >= suballocations1st.back().offset + suballocations1st.back().size);
            // Check if it fits before the end of the block.
            VMA_ASSERT(request.offset + allocSize <= GetSize());

            suballocations1st.push_back(newSuballoc);
        }
        break;
    case VmaAllocationRequestType::EndOf2nd:
        {
            SuballocationVectorType& suballocations1st = AccessSuballocations1st();
            // New allocation at the end of 2-part ring buffer, so before first allocation from 1st vector.
            VMA_ASSERT(!suballocations1st.empty() &&
                request.offset + allocSize <= suballocations1st[m_1stNullItemsBeginCount].offset);
            SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();

            switch(m_2ndVectorMode)
            {
            case SECOND_VECTOR_EMPTY:
                // First allocation from second part ring buffer.
                VMA_ASSERT(suballocations2nd.empty());
                m_2ndVectorMode = SECOND_VECTOR_RING_BUFFER;
                break;
            case SECOND_VECTOR_RING_BUFFER:
                // 2-part ring buffer is already started.
                VMA_ASSERT(!suballocations2nd.empty());
                break;
            case SECOND_VECTOR_DOUBLE_STACK:
                VMA_ASSERT(0 && "CRITICAL ERROR: Trying to use linear allocator as ring buffer while it was already used as double stack.");
                break;
            default:
                VMA_ASSERT(0);
            }

            suballocations2nd.push_back(newSuballoc);
        }
        break;
    default:
        VMA_ASSERT(0 && "CRITICAL INTERNAL ERROR.");
    }

    m_SumFreeSize -= newSuballoc.size;
}

void VmaBlockMetadata_Linear::Free(const VmaAllocation allocation)
{
    FreeAtOffset(allocation->GetOffset());
}

void VmaBlockMetadata_Linear::FreeAtOffset(VkDeviceSize offset)
{
    SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();

    if(!suballocations1st.empty())
    {
        // First allocation: Mark it as next empty at the beginning.
        VmaSuballocation& firstSuballoc = suballocations1st[m_1stNullItemsBeginCount];
        if(firstSuballoc.offset == offset)
        {
            firstSuballoc.type = VMA_SUBALLOCATION_TYPE_FREE;
            firstSuballoc.hAllocation = VK_NULL_HANDLE;
            m_SumFreeSize += firstSuballoc.size;
            ++m_1stNullItemsBeginCount;
            CleanupAfterFree();
            return;
        }
    }

    // Last allocation in 2-part ring buffer or top of upper stack (same logic).
    if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER ||
        m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK)
    {
        VmaSuballocation& lastSuballoc = suballocations2nd.back();
        if(lastSuballoc.offset == offset)
        {
            m_SumFreeSize += lastSuballoc.size;
            suballocations2nd.pop_back();
            CleanupAfterFree();
            return;
        }
    }
    // Last allocation in 1st vector.
    else if(m_2ndVectorMode == SECOND_VECTOR_EMPTY)
    {
        VmaSuballocation& lastSuballoc = suballocations1st.back();
        if(lastSuballoc.offset == offset)
        {
            m_SumFreeSize += lastSuballoc.size;
            suballocations1st.pop_back();
            CleanupAfterFree();
            return;
        }
    }

    // Item from the middle of 1st vector.
    {
        VmaSuballocation refSuballoc;
        refSuballoc.offset = offset;
        // Rest of members stays uninitialized intentionally for better performance.
        SuballocationVectorType::iterator it = VmaVectorFindSorted<VmaSuballocationOffsetLess>(
            suballocations1st.begin() + m_1stNullItemsBeginCount,
            suballocations1st.end(),
            refSuballoc);
        if(it != suballocations1st.end())
        {
            it->type = VMA_SUBALLOCATION_TYPE_FREE;
            it->hAllocation = VK_NULL_HANDLE;
            ++m_1stNullItemsMiddleCount;
            m_SumFreeSize += it->size;
            CleanupAfterFree();
            return;
        }
    }

    if(m_2ndVectorMode != SECOND_VECTOR_EMPTY)
    {
        // Item from the middle of 2nd vector.
        VmaSuballocation refSuballoc;
        refSuballoc.offset = offset;
        // Rest of members stays uninitialized intentionally for better performance.
        SuballocationVectorType::iterator it = m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER ?
            VmaVectorFindSorted<VmaSuballocationOffsetLess>(suballocations2nd.begin(), suballocations2nd.end(), refSuballoc) :
            VmaVectorFindSorted<VmaSuballocationOffsetGreater>(suballocations2nd.begin(), suballocations2nd.end(), refSuballoc);
        if(it != suballocations2nd.end())
        {
            it->type = VMA_SUBALLOCATION_TYPE_FREE;
            it->hAllocation = VK_NULL_HANDLE;
            ++m_2ndNullItemsCount;
            m_SumFreeSize += it->size;
            CleanupAfterFree();
            return;
        }
    }

    VMA_ASSERT(0 && "Allocation to free not found in linear allocator!");
}

bool VmaBlockMetadata_Linear::ShouldCompact1st() const
{
    const size_t nullItemCount = m_1stNullItemsBeginCount + m_1stNullItemsMiddleCount;
    const size_t suballocCount = AccessSuballocations1st().size();
    return suballocCount > 32 && nullItemCount * 2 >= (suballocCount - nullItemCount) * 3;
}

void VmaBlockMetadata_Linear::CleanupAfterFree()
{
    SuballocationVectorType& suballocations1st = AccessSuballocations1st();
    SuballocationVectorType& suballocations2nd = AccessSuballocations2nd();

    if(IsEmpty())
    {
        suballocations1st.clear();
        suballocations2nd.clear();
        m_1stNullItemsBeginCount = 0;
        m_1stNullItemsMiddleCount = 0;
        m_2ndNullItemsCount = 0;
        m_2ndVectorMode = SECOND_VECTOR_EMPTY;
    }
    else
    {
        const size_t suballoc1stCount = suballocations1st.size();
        const size_t nullItem1stCount = m_1stNullItemsBeginCount + m_1stNullItemsMiddleCount;
        VMA_ASSERT(nullItem1stCount <= suballoc1stCount);

        // Find more null items at the beginning of 1st vector.
        while(m_1stNullItemsBeginCount < suballoc1stCount &&
            suballocations1st[m_1stNullItemsBeginCount].hAllocation == VK_NULL_HANDLE)
        {
            ++m_1stNullItemsBeginCount;
            --m_1stNullItemsMiddleCount;
        }

        // Find more null items at the end of 1st vector.
        while(m_1stNullItemsMiddleCount > 0 &&
            suballocations1st.back().hAllocation == VK_NULL_HANDLE)
        {
            --m_1stNullItemsMiddleCount;
            suballocations1st.pop_back();
        }

        // Find more null items at the end of 2nd vector.
        while(m_2ndNullItemsCount > 0 &&
            suballocations2nd.back().hAllocation == VK_NULL_HANDLE)
        {
            --m_2ndNullItemsCount;
            suballocations2nd.pop_back();
        }

        // Find more null items at the beginning of 2nd vector.
        while(m_2ndNullItemsCount > 0 &&
            suballocations2nd[0].hAllocation == VK_NULL_HANDLE)
        {
            --m_2ndNullItemsCount;
            suballocations2nd.remove(0);
        }

        if(ShouldCompact1st())
        {
            const size_t nonNullItemCount = suballoc1stCount - nullItem1stCount;
            size_t srcIndex = m_1stNullItemsBeginCount;
            for(size_t dstIndex = 0; dstIndex < nonNullItemCount; ++dstIndex)
            {
                while(suballocations1st[srcIndex].hAllocation == VK_NULL_HANDLE)
                {
                    ++srcIndex;
                }
                if(dstIndex != srcIndex)
                {
                    suballocations1st[dstIndex] = suballocations1st[srcIndex];
                }
                ++srcIndex;
            }
            suballocations1st.resize(nonNullItemCount);
            m_1stNullItemsBeginCount = 0;
            m_1stNullItemsMiddleCount = 0;
        }

        // 2nd vector became empty.
        if(suballocations2nd.empty())
        {
            m_2ndVectorMode = SECOND_VECTOR_EMPTY;
        }

        // 1st vector became empty.
        if(suballocations1st.size() - m_1stNullItemsBeginCount == 0)
        {
            suballocations1st.clear();
            m_1stNullItemsBeginCount = 0;

            if(!suballocations2nd.empty() && m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER)
            {
                // Swap 1st with 2nd. Now 2nd is empty.
                m_2ndVectorMode = SECOND_VECTOR_EMPTY;
                m_1stNullItemsMiddleCount = m_2ndNullItemsCount;
                while(m_1stNullItemsBeginCount < suballocations2nd.size() &&
                    suballocations2nd[m_1stNullItemsBeginCount].hAllocation == VK_NULL_HANDLE)
                {
                    ++m_1stNullItemsBeginCount;
                    --m_1stNullItemsMiddleCount;
                }
                m_2ndNullItemsCount = 0;
                m_1stVectorIndex ^= 1;
            }
        }
    }

    VMA_HEAVY_ASSERT(Validate());
}


// class VmaBlockMetadata_Buddy

VmaBlockMetadata_Buddy::VmaBlockMetadata_Buddy(VmaAllocator hAllocator) :
    VmaBlockMetadata(hAllocator),
    m_Root(VMA_NULL),
    m_AllocationCount(0),
    m_FreeCount(1),
    m_SumFreeSize(0)
{
    memset(m_FreeList, 0, sizeof(m_FreeList));
}

VmaBlockMetadata_Buddy::~VmaBlockMetadata_Buddy()
{
    DeleteNode(m_Root);
}

void VmaBlockMetadata_Buddy::Init(VkDeviceSize size)
{
    VmaBlockMetadata::Init(size);

    m_UsableSize = VmaPrevPow2(size);
    m_SumFreeSize = m_UsableSize;

    // Calculate m_LevelCount.
    m_LevelCount = 1;
    while(m_LevelCount < MAX_LEVELS &&
        LevelToNodeSize(m_LevelCount) >= MIN_NODE_SIZE)
    {
        ++m_LevelCount;
    }

    Node* rootNode = vma_new(GetAllocationCallbacks(), Node)();
    rootNode->offset = 0;
    rootNode->type = Node::TYPE_FREE;
    rootNode->parent = VMA_NULL;
    rootNode->buddy = VMA_NULL;

    m_Root = rootNode;
    AddToFreeListFront(0, rootNode);
}

bool VmaBlockMetadata_Buddy::Validate() const
{
    // Validate tree.
    ValidationContext ctx;
    if(!ValidateNode(ctx, VMA_NULL, m_Root, 0, LevelToNodeSize(0)))
    {
        VMA_VALIDATE(false && "ValidateNode failed.");
    }
    VMA_VALIDATE(m_AllocationCount == ctx.calculatedAllocationCount);
    VMA_VALIDATE(m_SumFreeSize == ctx.calculatedSumFreeSize);

    // Validate free node lists.
    for(uint32_t level = 0; level < m_LevelCount; ++level)
    {
        VMA_VALIDATE(m_FreeList[level].front == VMA_NULL ||
            m_FreeList[level].front->free.prev == VMA_NULL);

        for(Node* node = m_FreeList[level].front;
            node != VMA_NULL;
            node = node->free.next)
        {
            VMA_VALIDATE(node->type == Node::TYPE_FREE);
            
            if(node->free.next == VMA_NULL)
            {
                VMA_VALIDATE(m_FreeList[level].back == node);
            }
            else
            {
                VMA_VALIDATE(node->free.next->free.prev == node);
            }
        }
    }

    // Validate that free lists ar higher levels are empty.
    for(uint32_t level = m_LevelCount; level < MAX_LEVELS; ++level)
    {
        VMA_VALIDATE(m_FreeList[level].front == VMA_NULL && m_FreeList[level].back == VMA_NULL);
    }

    return true;
}

VkDeviceSize VmaBlockMetadata_Buddy::GetUnusedRangeSizeMax() const
{
    for(uint32_t level = 0; level < m_LevelCount; ++level)
    {
        if(m_FreeList[level].front != VMA_NULL)
        {
            return LevelToNodeSize(level);
        }
    }
    return 0;
}

void VmaBlockMetadata_Buddy::CalcAllocationStatInfo(VmaStatInfo& outInfo) const
{
    const VkDeviceSize unusableSize = GetUnusableSize();

    outInfo.blockCount = 1;

    outInfo.allocationCount = outInfo.unusedRangeCount = 0;
    outInfo.usedBytes = outInfo.unusedBytes = 0;

    outInfo.allocationSizeMax = outInfo.unusedRangeSizeMax = 0;
    outInfo.allocationSizeMin = outInfo.unusedRangeSizeMin = UINT64_MAX;
    outInfo.allocationSizeAvg = outInfo.unusedRangeSizeAvg = 0; // Unused.

    CalcAllocationStatInfoNode(outInfo, m_Root, LevelToNodeSize(0));

    if(unusableSize > 0)
    {
        ++outInfo.unusedRangeCount;
        outInfo.unusedBytes += unusableSize;
        outInfo.unusedRangeSizeMax = VMA_MAX(outInfo.unusedRangeSizeMax, unusableSize);
        outInfo.unusedRangeSizeMin = VMA_MIN(outInfo.unusedRangeSizeMin, unusableSize);
    }
}

void VmaBlockMetadata_Buddy::AddPoolStats(VmaPoolStats& inoutStats) const
{
    const VkDeviceSize unusableSize = GetUnusableSize();

    inoutStats.size += GetSize();
    inoutStats.unusedSize += m_SumFreeSize + unusableSize;
    inoutStats.allocationCount += m_AllocationCount;
    inoutStats.unusedRangeCount += m_FreeCount;
    inoutStats.unusedRangeSizeMax = VMA_MAX(inoutStats.unusedRangeSizeMax, GetUnusedRangeSizeMax());

    if(unusableSize > 0)
    {
        ++inoutStats.unusedRangeCount;
        // Not updating inoutStats.unusedRangeSizeMax with unusableSize because this space is not available for allocations.
    }
}

#if VMA_STATS_STRING_ENABLED

void VmaBlockMetadata_Buddy::PrintDetailedMap(class VmaJsonWriter& json) const
{
    // TODO optimize
    VmaStatInfo stat;
    CalcAllocationStatInfo(stat);

    PrintDetailedMap_Begin(
        json,
        stat.unusedBytes,
        stat.allocationCount,
        stat.unusedRangeCount);

    PrintDetailedMapNode(json, m_Root, LevelToNodeSize(0));

    const VkDeviceSize unusableSize = GetUnusableSize();
    if(unusableSize > 0)
    {
        PrintDetailedMap_UnusedRange(json,
            m_UsableSize, // offset
            unusableSize); // size
    }

    PrintDetailedMap_End(json);
}

#endif // #if VMA_STATS_STRING_ENABLED

bool VmaBlockMetadata_Buddy::CreateAllocationRequest(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VkDeviceSize bufferImageGranularity,
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    bool upperAddress,
    VmaSuballocationType allocType,
    bool canMakeOtherLost,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{
    VMA_ASSERT(!upperAddress && "VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT can be used only with linear algorithm.");

    // Simple way to respect bufferImageGranularity. May be optimized some day.
    // Whenever it might be an OPTIMAL image...
    if(allocType == VMA_SUBALLOCATION_TYPE_UNKNOWN ||
        allocType == VMA_SUBALLOCATION_TYPE_IMAGE_UNKNOWN ||
        allocType == VMA_SUBALLOCATION_TYPE_IMAGE_OPTIMAL)
    {
        allocAlignment = VMA_MAX(allocAlignment, bufferImageGranularity);
        allocSize = VMA_MAX(allocSize, bufferImageGranularity);
    }

    if(allocSize > m_UsableSize)
    {
        return false;
    }

    const uint32_t targetLevel = AllocSizeToLevel(allocSize);
    for(uint32_t level = targetLevel + 1; level--; )
    {
        for(Node* freeNode = m_FreeList[level].front;
            freeNode != VMA_NULL;
            freeNode = freeNode->free.next)
        {
            if(freeNode->offset % allocAlignment == 0)
            {
                pAllocationRequest->type = VmaAllocationRequestType::Normal;
                pAllocationRequest->offset = freeNode->offset;
                pAllocationRequest->sumFreeSize = LevelToNodeSize(level);
                pAllocationRequest->sumItemSize = 0;
                pAllocationRequest->itemsToMakeLostCount = 0;
                pAllocationRequest->customData = (void*)(uintptr_t)level;
                return true;
            }
        }
    }

    return false;
}

bool VmaBlockMetadata_Buddy::MakeRequestedAllocationsLost(
    uint32_t currentFrameIndex,
    uint32_t frameInUseCount,
    VmaAllocationRequest* pAllocationRequest)
{
    /*
    Lost allocations are not supported in buddy allocator at the moment.
    Support might be added in the future.
    */
    return pAllocationRequest->itemsToMakeLostCount == 0;
}

uint32_t VmaBlockMetadata_Buddy::MakeAllocationsLost(uint32_t currentFrameIndex, uint32_t frameInUseCount)
{
    /*
    Lost allocations are not supported in buddy allocator at the moment.
    Support might be added in the future.
    */
    return 0;
}

void VmaBlockMetadata_Buddy::Alloc(
    const VmaAllocationRequest& request,
    VmaSuballocationType type,
    VkDeviceSize allocSize,
    VmaAllocation hAllocation)
{
    VMA_ASSERT(request.type == VmaAllocationRequestType::Normal);

    const uint32_t targetLevel = AllocSizeToLevel(allocSize);
    uint32_t currLevel = (uint32_t)(uintptr_t)request.customData;
    
    Node* currNode = m_FreeList[currLevel].front;
    VMA_ASSERT(currNode != VMA_NULL && currNode->type == Node::TYPE_FREE);
    while(currNode->offset != request.offset)
    {
        currNode = currNode->free.next;
        VMA_ASSERT(currNode != VMA_NULL && currNode->type == Node::TYPE_FREE);
    }
    
    // Go down, splitting free nodes.
    while(currLevel < targetLevel)
    {
        // currNode is already first free node at currLevel.
        // Remove it from list of free nodes at this currLevel.
        RemoveFromFreeList(currLevel, currNode);
         
        const uint32_t childrenLevel = currLevel + 1;

        // Create two free sub-nodes.
        Node* leftChild = vma_new(GetAllocationCallbacks(), Node)();
        Node* rightChild = vma_new(GetAllocationCallbacks(), Node)();

        leftChild->offset = currNode->offset;
        leftChild->type = Node::TYPE_FREE;
        leftChild->parent = currNode;
        leftChild->buddy = rightChild;

        rightChild->offset = currNode->offset + LevelToNodeSize(childrenLevel);
        rightChild->type = Node::TYPE_FREE;
        rightChild->parent = currNode;
        rightChild->buddy = leftChild;

        // Convert current currNode to split type.
        currNode->type = Node::TYPE_SPLIT;
        currNode->split.leftChild = leftChild;

        // Add child nodes to free list. Order is important!
        AddToFreeListFront(childrenLevel, rightChild);
        AddToFreeListFront(childrenLevel, leftChild);

        ++m_FreeCount;
        //m_SumFreeSize -= LevelToNodeSize(currLevel) % 2; // Useful only when level node sizes can be non power of 2.
        ++currLevel;
        currNode = m_FreeList[currLevel].front;

        /*
        We can be sure that currNode, as left child of node previously split,
        also fullfills the alignment requirement.
        */
    }

    // Remove from free list.
    VMA_ASSERT(currLevel == targetLevel &&
        currNode != VMA_NULL &&
        currNode->type == Node::TYPE_FREE);
    RemoveFromFreeList(currLevel, currNode);

    // Convert to allocation node.
    currNode->type = Node::TYPE_ALLOCATION;
    currNode->allocation.alloc = hAllocation;

    ++m_AllocationCount;
    --m_FreeCount;
    m_SumFreeSize -= allocSize;
}

void VmaBlockMetadata_Buddy::DeleteNode(Node* node)
{
    if(node->type == Node::TYPE_SPLIT)
    {
        DeleteNode(node->split.leftChild->buddy);
        DeleteNode(node->split.leftChild);
    }

    vma_delete(GetAllocationCallbacks(), node);
}

bool VmaBlockMetadata_Buddy::ValidateNode(ValidationContext& ctx, const Node* parent, const Node* curr, uint32_t level, VkDeviceSize levelNodeSize) const
{
    VMA_VALIDATE(level < m_LevelCount);
    VMA_VALIDATE(curr->parent == parent);
    VMA_VALIDATE((curr->buddy == VMA_NULL) == (parent == VMA_NULL));
    VMA_VALIDATE(curr->buddy == VMA_NULL || curr->buddy->buddy == curr);
    switch(curr->type)
    {
    case Node::TYPE_FREE:
        // curr->free.prev, next are validated separately.
        ctx.calculatedSumFreeSize += levelNodeSize;
        ++ctx.calculatedFreeCount;
        break;
    case Node::TYPE_ALLOCATION:
        ++ctx.calculatedAllocationCount;
        ctx.calculatedSumFreeSize += levelNodeSize - curr->allocation.alloc->GetSize();
        VMA_VALIDATE(curr->allocation.alloc != VK_NULL_HANDLE);
        break;
    case Node::TYPE_SPLIT:
        {
            const uint32_t childrenLevel = level + 1;
            const VkDeviceSize childrenLevelNodeSize = levelNodeSize / 2;
            const Node* const leftChild = curr->split.leftChild;
            VMA_VALIDATE(leftChild != VMA_NULL);
            VMA_VALIDATE(leftChild->offset == curr->offset);
            if(!ValidateNode(ctx, curr, leftChild, childrenLevel, childrenLevelNodeSize))
            {
                VMA_VALIDATE(false && "ValidateNode for left child failed.");
            }
            const Node* const rightChild = leftChild->buddy;
            VMA_VALIDATE(rightChild->offset == curr->offset + childrenLevelNodeSize);
            if(!ValidateNode(ctx, curr, rightChild, childrenLevel, childrenLevelNodeSize))
            {
                VMA_VALIDATE(false && "ValidateNode for right child failed.");
            }
        }
        break;
    default:
        return false;
    }

    return true;
}

uint32_t VmaBlockMetadata_Buddy::AllocSizeToLevel(VkDeviceSize allocSize) const
{
    // I know this could be optimized somehow e.g. by using std::log2p1 from C++20.
    uint32_t level = 0;
    VkDeviceSize currLevelNodeSize = m_UsableSize;
    VkDeviceSize nextLevelNodeSize = currLevelNodeSize >> 1;
    while(allocSize <= nextLevelNodeSize && level + 1 < m_LevelCount)
    {
        ++level;
        currLevelNodeSize = nextLevelNodeSize;
        nextLevelNodeSize = currLevelNodeSize >> 1;
    }
    return level;
}

void VmaBlockMetadata_Buddy::FreeAtOffset(VmaAllocation alloc, VkDeviceSize offset)
{
    // Find node and level.
    Node* node = m_Root;
    VkDeviceSize nodeOffset = 0;
    uint32_t level = 0;
    VkDeviceSize levelNodeSize = LevelToNodeSize(0);
    while(node->type == Node::TYPE_SPLIT)
    {
        const VkDeviceSize nextLevelSize = levelNodeSize >> 1;
        if(offset < nodeOffset + nextLevelSize)
        {
            node = node->split.leftChild;
        }
        else
        {
            node = node->split.leftChild->buddy;
            nodeOffset += nextLevelSize;
        }
        ++level;
        levelNodeSize = nextLevelSize;
    }

    VMA_ASSERT(node != VMA_NULL && node->type == Node::TYPE_ALLOCATION);
    VMA_ASSERT(alloc == VK_NULL_HANDLE || node->allocation.alloc == alloc);

    ++m_FreeCount;
    --m_AllocationCount;
    m_SumFreeSize += alloc->GetSize();

    node->type = Node::TYPE_FREE;

    // Join free nodes if possible.
    while(level > 0 && node->buddy->type == Node::TYPE_FREE)
    {
        RemoveFromFreeList(level, node->buddy);
        Node* const parent = node->parent;

        vma_delete(GetAllocationCallbacks(), node->buddy);
        vma_delete(GetAllocationCallbacks(), node);
        parent->type = Node::TYPE_FREE;
        
        node = parent;
        --level;
        //m_SumFreeSize += LevelToNodeSize(level) % 2; // Useful only when level node sizes can be non power of 2.
        --m_FreeCount;
    }

    AddToFreeListFront(level, node);
}

void VmaBlockMetadata_Buddy::CalcAllocationStatInfoNode(VmaStatInfo& outInfo, const Node* node, VkDeviceSize levelNodeSize) const
{
    switch(node->type)
    {
    case Node::TYPE_FREE:
        ++outInfo.unusedRangeCount;
        outInfo.unusedBytes += levelNodeSize;
        outInfo.unusedRangeSizeMax = VMA_MAX(outInfo.unusedRangeSizeMax, levelNodeSize);
        outInfo.unusedRangeSizeMin = VMA_MAX(outInfo.unusedRangeSizeMin, levelNodeSize);
        break;
    case Node::TYPE_ALLOCATION:
        {
            const VkDeviceSize allocSize = node->allocation.alloc->GetSize();
            ++outInfo.allocationCount;
            outInfo.usedBytes += allocSize;
            outInfo.allocationSizeMax = VMA_MAX(outInfo.allocationSizeMax, allocSize);
            outInfo.allocationSizeMin = VMA_MAX(outInfo.allocationSizeMin, allocSize);

            const VkDeviceSize unusedRangeSize = levelNodeSize - allocSize;
            if(unusedRangeSize > 0)
            {
                ++outInfo.unusedRangeCount;
                outInfo.unusedBytes += unusedRangeSize;
                outInfo.unusedRangeSizeMax = VMA_MAX(outInfo.unusedRangeSizeMax, unusedRangeSize);
                outInfo.unusedRangeSizeMin = VMA_MAX(outInfo.unusedRangeSizeMin, unusedRangeSize);
            }
        }
        break;
    case Node::TYPE_SPLIT:
        {
            const VkDeviceSize childrenNodeSize = levelNodeSize / 2;
            const Node* const leftChild = node->split.leftChild;
            CalcAllocationStatInfoNode(outInfo, leftChild, childrenNodeSize);
            const Node* const rightChild = leftChild->buddy;
            CalcAllocationStatInfoNode(outInfo, rightChild, childrenNodeSize);
        }
        break;
    default:
        VMA_ASSERT(0);
    }
}

void VmaBlockMetadata_Buddy::AddToFreeListFront(uint32_t level, Node* node)
{
    VMA_ASSERT(node->type == Node::TYPE_FREE);

    // List is empty.
    Node* const frontNode = m_FreeList[level].front;
    if(frontNode == VMA_NULL)
    {
        VMA_ASSERT(m_FreeList[level].back == VMA_NULL);
        node->free.prev = node->free.next = VMA_NULL;
        m_FreeList[level].front = m_FreeList[level].back = node;
    }
    else
    {
        VMA_ASSERT(frontNode->free.prev == VMA_NULL);
        node->free.prev = VMA_NULL;
        node->free.next = frontNode;
        frontNode->free.prev = node;
        m_FreeList[level].front = node;
    }
}

void VmaBlockMetadata_Buddy::RemoveFromFreeList(uint32_t level, Node* node)
{
    VMA_ASSERT(m_FreeList[level].front != VMA_NULL);

    // It is at the front.
    if(node->free.prev == VMA_NULL)
    {
        VMA_ASSERT(m_FreeList[level].front == node);
        m_FreeList[level].front = node->free.next;
    }
    else
    {
        Node* const prevFreeNode = node->free.prev;
        VMA_ASSERT(prevFreeNode->free.next == node);
        prevFreeNode->free.next = node->free.next;
    }

    // It is at the back.
    if(node->free.next == VMA_NULL)
    {
        VMA_ASSERT(m_FreeList[level].back == node);
        m_FreeList[level].back = node->free.prev;
    }
    else
    {
        Node* const nextFreeNode = node->free.next;
        VMA_ASSERT(nextFreeNode->free.prev == node);
        nextFreeNode->free.prev = node->free.prev;
    }
}

#if VMA_STATS_STRING_ENABLED
void VmaBlockMetadata_Buddy::PrintDetailedMapNode(class VmaJsonWriter& json, const Node* node, VkDeviceSize levelNodeSize) const
{
    switch(node->type)
    {
    case Node::TYPE_FREE:
        PrintDetailedMap_UnusedRange(json, node->offset, levelNodeSize);
        break;
    case Node::TYPE_ALLOCATION:
        {   
            PrintDetailedMap_Allocation(json, node->offset, node->allocation.alloc);
            const VkDeviceSize allocSize = node->allocation.alloc->GetSize();
            if(allocSize < levelNodeSize)
            {
                PrintDetailedMap_UnusedRange(json, node->offset + allocSize, levelNodeSize - allocSize);
            }
        }
        break;
    case Node::TYPE_SPLIT:
        {
            const VkDeviceSize childrenNodeSize = levelNodeSize / 2;
            const Node* const leftChild = node->split.leftChild;
            PrintDetailedMapNode(json, leftChild, childrenNodeSize);
            const Node* const rightChild = leftChild->buddy;
            PrintDetailedMapNode(json, rightChild, childrenNodeSize);
        }
        break;
    default:
        VMA_ASSERT(0);
    }
}
#endif // #if VMA_STATS_STRING_ENABLED


// class VmaDeviceMemoryBlock

VmaDeviceMemoryBlock::VmaDeviceMemoryBlock(VmaAllocator hAllocator) :
    m_pMetadata(VMA_NULL),
    m_MemoryTypeIndex(UINT32_MAX),
    m_Id(0),
    m_hMemory(VK_NULL_HANDLE),
    m_MapCount(0),
    m_pMappedData(VMA_NULL)
{
}

void VmaDeviceMemoryBlock::Init(
    VmaAllocator hAllocator,
    VmaPool hParentPool,
    uint32_t newMemoryTypeIndex,
    VkDeviceMemory newMemory,
    VkDeviceSize newSize,
    uint32_t id,
    uint32_t algorithm)
{
    VMA_ASSERT(m_hMemory == VK_NULL_HANDLE);

    m_hParentPool = hParentPool;
    m_MemoryTypeIndex = newMemoryTypeIndex;
    m_Id = id;
    m_hMemory = newMemory;

    switch(algorithm)
    {
    case VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT:
        m_pMetadata = vma_new(hAllocator, VmaBlockMetadata_Linear)(hAllocator);
        break;
    case VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT:
        m_pMetadata = vma_new(hAllocator, VmaBlockMetadata_Buddy)(hAllocator);
        break;
    default:
        VMA_ASSERT(0);
        // Fall-through.
    case 0:
        m_pMetadata = vma_new(hAllocator, VmaBlockMetadata_Generic)(hAllocator);
    }
    m_pMetadata->Init(newSize);
}

void VmaDeviceMemoryBlock::Destroy(VmaAllocator allocator)
{
    // This is the most important assert in the entire library.
    // Hitting it means you have some memory leak - unreleased VmaAllocation objects.
    VMA_ASSERT(m_pMetadata->IsEmpty() && "Some allocations were not freed before destruction of this memory block!");

    VMA_ASSERT(m_hMemory != VK_NULL_HANDLE);
    allocator->FreeVulkanMemory(m_MemoryTypeIndex, m_pMetadata->GetSize(), m_hMemory);
    m_hMemory = VK_NULL_HANDLE;

    vma_delete(allocator, m_pMetadata);
    m_pMetadata = VMA_NULL;
}

bool VmaDeviceMemoryBlock::Validate() const
{
    VMA_VALIDATE((m_hMemory != VK_NULL_HANDLE) &&
        (m_pMetadata->GetSize() != 0));
    
    return m_pMetadata->Validate();
}

VkResult VmaDeviceMemoryBlock::CheckCorruption(VmaAllocator hAllocator)
{
    void* pData = nullptr;
    VkResult res = Map(hAllocator, 1, &pData);
    if(res != VK_SUCCESS)
    {
        return res;
    }

    res = m_pMetadata->CheckCorruption(pData);

    Unmap(hAllocator, 1);

    return res;
}

VkResult VmaDeviceMemoryBlock::Map(VmaAllocator hAllocator, uint32_t count, void** ppData)
{
    if(count == 0)
    {
        return VK_SUCCESS;
    }

    VmaMutexLock lock(m_Mutex, hAllocator->m_UseMutex);
    if(m_MapCount != 0)
    {
        m_MapCount += count;
        VMA_ASSERT(m_pMappedData != VMA_NULL);
        if(ppData != VMA_NULL)
        {
            *ppData = m_pMappedData;
        }
        return VK_SUCCESS;
    }
    else
    {
        VkResult result = (*hAllocator->GetVulkanFunctions().vkMapMemory)(
            hAllocator->m_hDevice,
            m_hMemory,
            0, // offset
            VK_WHOLE_SIZE,
            0, // flags
            &m_pMappedData);
        if(result == VK_SUCCESS)
        {
            if(ppData != VMA_NULL)
            {
                *ppData = m_pMappedData;
            }
            m_MapCount = count;
        }
        return result;
    }
}

void VmaDeviceMemoryBlock::Unmap(VmaAllocator hAllocator, uint32_t count)
{
    if(count == 0)
    {
        return;
    }

    VmaMutexLock lock(m_Mutex, hAllocator->m_UseMutex);
    if(m_MapCount >= count)
    {
        m_MapCount -= count;
        if(m_MapCount == 0)
        {
            m_pMappedData = VMA_NULL;
            (*hAllocator->GetVulkanFunctions().vkUnmapMemory)(hAllocator->m_hDevice, m_hMemory);
        }
    }
    else
    {
        VMA_ASSERT(0 && "VkDeviceMemory block is being unmapped while it was not previously mapped.");
    }
}

VkResult VmaDeviceMemoryBlock::WriteMagicValueAroundAllocation(VmaAllocator hAllocator, VkDeviceSize allocOffset, VkDeviceSize allocSize)
{
    VMA_ASSERT(VMA_DEBUG_MARGIN > 0 && VMA_DEBUG_MARGIN % 4 == 0 && VMA_DEBUG_DETECT_CORRUPTION);
    VMA_ASSERT(allocOffset >= VMA_DEBUG_MARGIN);

    void* pData;
    VkResult res = Map(hAllocator, 1, &pData);
    if(res != VK_SUCCESS)
    {
        return res;
    }

    VmaWriteMagicValue(pData, allocOffset - VMA_DEBUG_MARGIN);
    VmaWriteMagicValue(pData, allocOffset + allocSize);

    Unmap(hAllocator, 1);

    return VK_SUCCESS;
}

VkResult VmaDeviceMemoryBlock::ValidateMagicValueAroundAllocation(VmaAllocator hAllocator, VkDeviceSize allocOffset, VkDeviceSize allocSize)
{
    VMA_ASSERT(VMA_DEBUG_MARGIN > 0 && VMA_DEBUG_MARGIN % 4 == 0 && VMA_DEBUG_DETECT_CORRUPTION);
    VMA_ASSERT(allocOffset >= VMA_DEBUG_MARGIN);

    void* pData;
    VkResult res = Map(hAllocator, 1, &pData);
    if(res != VK_SUCCESS)
    {
        return res;
    }

    if(!VmaValidateMagicValue(pData, allocOffset - VMA_DEBUG_MARGIN))
    {
        VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED BEFORE FREED ALLOCATION!");
    }
    else if(!VmaValidateMagicValue(pData, allocOffset + allocSize))
    {
        VMA_ASSERT(0 && "MEMORY CORRUPTION DETECTED AFTER FREED ALLOCATION!");
    }

    Unmap(hAllocator, 1);

    return VK_SUCCESS;
}

VkResult VmaDeviceMemoryBlock::BindBufferMemory(
    const VmaAllocator hAllocator,
    const VmaAllocation hAllocation,
    VkBuffer hBuffer)
{
    VMA_ASSERT(hAllocation->GetType() == VmaAllocation_T::ALLOCATION_TYPE_BLOCK &&
        hAllocation->GetBlock() == this);
    // This lock is important so that we don't call vkBind... and/or vkMap... simultaneously on the same VkDeviceMemory from multiple threads.
    VmaMutexLock lock(m_Mutex, hAllocator->m_UseMutex);
    return hAllocator->GetVulkanFunctions().vkBindBufferMemory(
        hAllocator->m_hDevice,
        hBuffer,
        m_hMemory,
        hAllocation->GetOffset());
}

VkResult VmaDeviceMemoryBlock::BindImageMemory(
    const VmaAllocator hAllocator,
    const VmaAllocation hAllocation,
    VkImage hImage)
{
    VMA_ASSERT(hAllocation->GetType() == VmaAllocation_T::ALLOCATION_TYPE_BLOCK &&
        hAllocation->GetBlock() == this);
    // This lock is important so that we don't call vkBind... and/or vkMap... simultaneously on the same VkDeviceMemory from multiple threads.
    VmaMutexLock lock(m_Mutex, hAllocator->m_UseMutex);
    return hAllocator->GetVulkanFunctions().vkBindImageMemory(
        hAllocator->m_hDevice,
        hImage,
        m_hMemory,
        hAllocation->GetOffset());
}

static void InitStatInfo(VmaStatInfo& outInfo)
{
    memset(&outInfo, 0, sizeof(outInfo));
    outInfo.allocationSizeMin = UINT64_MAX;
    outInfo.unusedRangeSizeMin = UINT64_MAX;
}

// Adds statistics srcInfo into inoutInfo, like: inoutInfo += srcInfo.
static void VmaAddStatInfo(VmaStatInfo& inoutInfo, const VmaStatInfo& srcInfo)
{
    inoutInfo.blockCount += srcInfo.blockCount;
    inoutInfo.allocationCount += srcInfo.allocationCount;
    inoutInfo.unusedRangeCount += srcInfo.unusedRangeCount;
    inoutInfo.usedBytes += srcInfo.usedBytes;
    inoutInfo.unusedBytes += srcInfo.unusedBytes;
    inoutInfo.allocationSizeMin = VMA_MIN(inoutInfo.allocationSizeMin, srcInfo.allocationSizeMin);
    inoutInfo.allocationSizeMax = VMA_MAX(inoutInfo.allocationSizeMax, srcInfo.allocationSizeMax);
    inoutInfo.unusedRangeSizeMin = VMA_MIN(inoutInfo.unusedRangeSizeMin, srcInfo.unusedRangeSizeMin);
    inoutInfo.unusedRangeSizeMax = VMA_MAX(inoutInfo.unusedRangeSizeMax, srcInfo.unusedRangeSizeMax);
}

static void VmaPostprocessCalcStatInfo(VmaStatInfo& inoutInfo)
{
    inoutInfo.allocationSizeAvg = (inoutInfo.allocationCount > 0) ?
        VmaRoundDiv<VkDeviceSize>(inoutInfo.usedBytes, inoutInfo.allocationCount) : 0;
    inoutInfo.unusedRangeSizeAvg = (inoutInfo.unusedRangeCount > 0) ?
        VmaRoundDiv<VkDeviceSize>(inoutInfo.unusedBytes, inoutInfo.unusedRangeCount) : 0;
}

VmaPool_T::VmaPool_T(
    VmaAllocator hAllocator,
    const VmaPoolCreateInfo& createInfo,
    VkDeviceSize preferredBlockSize) :
    m_BlockVector(
        hAllocator,
        this, // hParentPool
        createInfo.memoryTypeIndex,
        createInfo.blockSize != 0 ? createInfo.blockSize : preferredBlockSize,
        createInfo.minBlockCount,
        createInfo.maxBlockCount,
        (createInfo.flags & VMA_POOL_CREATE_IGNORE_BUFFER_IMAGE_GRANULARITY_BIT) != 0 ? 1 : hAllocator->GetBufferImageGranularity(),
        createInfo.frameInUseCount,
        true, // isCustomPool
        createInfo.blockSize != 0, // explicitBlockSize
        createInfo.flags & VMA_POOL_CREATE_ALGORITHM_MASK), // algorithm
    m_Id(0)
{
}

VmaPool_T::~VmaPool_T()
{
}

#if VMA_STATS_STRING_ENABLED

#endif // #if VMA_STATS_STRING_ENABLED

VmaBlockVector::VmaBlockVector(
    VmaAllocator hAllocator,
    VmaPool hParentPool,
    uint32_t memoryTypeIndex,
    VkDeviceSize preferredBlockSize,
    size_t minBlockCount,
    size_t maxBlockCount,
    VkDeviceSize bufferImageGranularity,
    uint32_t frameInUseCount,
    bool isCustomPool,
    bool explicitBlockSize,
    uint32_t algorithm) :
    m_hAllocator(hAllocator),
    m_hParentPool(hParentPool),
    m_MemoryTypeIndex(memoryTypeIndex),
    m_PreferredBlockSize(preferredBlockSize),
    m_MinBlockCount(minBlockCount),
    m_MaxBlockCount(maxBlockCount),
    m_BufferImageGranularity(bufferImageGranularity),
    m_FrameInUseCount(frameInUseCount),
    m_IsCustomPool(isCustomPool),
    m_ExplicitBlockSize(explicitBlockSize),
    m_Algorithm(algorithm),
    m_HasEmptyBlock(false),
    m_Blocks(VmaStlAllocator<VmaDeviceMemoryBlock*>(hAllocator->GetAllocationCallbacks())),
    m_NextBlockId(0)
{
}

VmaBlockVector::~VmaBlockVector()
{
    for(size_t i = m_Blocks.size(); i--; )
    {
        m_Blocks[i]->Destroy(m_hAllocator);
        vma_delete(m_hAllocator, m_Blocks[i]);
    }
}

VkResult VmaBlockVector::CreateMinBlocks()
{
    for(size_t i = 0; i < m_MinBlockCount; ++i)
    {
        VkResult res = CreateBlock(m_PreferredBlockSize, VMA_NULL);
        if(res != VK_SUCCESS)
        {
            return res;
        }
    }
    return VK_SUCCESS;
}

void VmaBlockVector::GetPoolStats(VmaPoolStats* pStats)
{
    VmaMutexLockRead lock(m_Mutex, m_hAllocator->m_UseMutex);

    const size_t blockCount = m_Blocks.size();

    pStats->size = 0;
    pStats->unusedSize = 0;
    pStats->allocationCount = 0;
    pStats->unusedRangeCount = 0;
    pStats->unusedRangeSizeMax = 0;
    pStats->blockCount = blockCount;

    for(uint32_t blockIndex = 0; blockIndex < blockCount; ++blockIndex)
    {
        const VmaDeviceMemoryBlock* const pBlock = m_Blocks[blockIndex];
        VMA_ASSERT(pBlock);
        VMA_HEAVY_ASSERT(pBlock->Validate());
        pBlock->m_pMetadata->AddPoolStats(*pStats);
    }
}

bool VmaBlockVector::IsCorruptionDetectionEnabled() const
{
    const uint32_t requiredMemFlags = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
    return (VMA_DEBUG_DETECT_CORRUPTION != 0) &&
        (VMA_DEBUG_MARGIN > 0) &&
        (m_Algorithm == 0 || m_Algorithm == VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT) &&
        (m_hAllocator->m_MemProps.memoryTypes[m_MemoryTypeIndex].propertyFlags & requiredMemFlags) == requiredMemFlags;
}

static const uint32_t VMA_ALLOCATION_TRY_COUNT = 32;

VkResult VmaBlockVector::Allocate(
    uint32_t currentFrameIndex,
    VkDeviceSize size,
    VkDeviceSize alignment,
    const VmaAllocationCreateInfo& createInfo,
    VmaSuballocationType suballocType,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{
    size_t allocIndex;
    VkResult res = VK_SUCCESS;

    if(IsCorruptionDetectionEnabled())
    {
        size = VmaAlignUp<VkDeviceSize>(size, sizeof(VMA_CORRUPTION_DETECTION_MAGIC_VALUE));
        alignment = VmaAlignUp<VkDeviceSize>(alignment, sizeof(VMA_CORRUPTION_DETECTION_MAGIC_VALUE));
    }

    {
        VmaMutexLockWrite lock(m_Mutex, m_hAllocator->m_UseMutex);
        for(allocIndex = 0; allocIndex < allocationCount; ++allocIndex)
        {
            res = AllocatePage(
                currentFrameIndex,
                size,
                alignment,
                createInfo,
                suballocType,
                pAllocations + allocIndex);
            if(res != VK_SUCCESS)
            {
                break;
            }
        }
    }

    if(res != VK_SUCCESS)
    {
        // Free all already created allocations.
        while(allocIndex--)
        {
            Free(pAllocations[allocIndex]);
        }
        memset(pAllocations, 0, sizeof(VmaAllocation) * allocationCount);
    }

    return res;
}

VkResult VmaBlockVector::AllocatePage(
    uint32_t currentFrameIndex,
    VkDeviceSize size,
    VkDeviceSize alignment,
    const VmaAllocationCreateInfo& createInfo,
    VmaSuballocationType suballocType,
    VmaAllocation* pAllocation)
{
    const bool isUpperAddress = (createInfo.flags & VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT) != 0;
    bool canMakeOtherLost = (createInfo.flags & VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT) != 0;
    const bool mapped = (createInfo.flags & VMA_ALLOCATION_CREATE_MAPPED_BIT) != 0;
    const bool isUserDataString = (createInfo.flags & VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT) != 0;
    const bool canCreateNewBlock =
        ((createInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) == 0) &&
        (m_Blocks.size() < m_MaxBlockCount);
    uint32_t strategy = createInfo.flags & VMA_ALLOCATION_CREATE_STRATEGY_MASK;

    // If linearAlgorithm is used, canMakeOtherLost is available only when used as ring buffer.
    // Which in turn is available only when maxBlockCount = 1.
    if(m_Algorithm == VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT && m_MaxBlockCount > 1)
    {
        canMakeOtherLost = false;
    }

    // Upper address can only be used with linear allocator and within single memory block.
    if(isUpperAddress &&
        (m_Algorithm != VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT || m_MaxBlockCount > 1))
    {
        return VK_ERROR_FEATURE_NOT_PRESENT;
    }

    // Validate strategy.
    switch(strategy)
    {
    case 0:
        strategy = VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT;
        break;
    case VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT:
    case VMA_ALLOCATION_CREATE_STRATEGY_WORST_FIT_BIT:
    case VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT:
        break;
    default:
        return VK_ERROR_FEATURE_NOT_PRESENT;
    }

    // Early reject: requested allocation size is larger that maximum block size for this block vector.
    if(size + 2 * VMA_DEBUG_MARGIN > m_PreferredBlockSize)
    {
        return VK_ERROR_OUT_OF_DEVICE_MEMORY;
    }

    /*
    Under certain condition, this whole section can be skipped for optimization, so
    we move on directly to trying to allocate with canMakeOtherLost. That's the case
    e.g. for custom pools with linear algorithm.
    */
    if(!canMakeOtherLost || canCreateNewBlock)
    {
        // 1. Search existing allocations. Try to allocate without making other allocations lost.
        VmaAllocationCreateFlags allocFlagsCopy = createInfo.flags;
        allocFlagsCopy &= ~VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT;

        if(m_Algorithm == VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT)
        {
            // Use only last block.
            if(!m_Blocks.empty())
            {
                VmaDeviceMemoryBlock* const pCurrBlock = m_Blocks.back();
                VMA_ASSERT(pCurrBlock);
                VkResult res = AllocateFromBlock(
                    pCurrBlock,
                    currentFrameIndex,
                    size,
                    alignment,
                    allocFlagsCopy,
                    createInfo.pUserData,
                    suballocType,
                    strategy,
                    pAllocation);
                if(res == VK_SUCCESS)
                {
                    VMA_DEBUG_LOG("    Returned from last block #%u", (uint32_t)(m_Blocks.size() - 1));
                    return VK_SUCCESS;
                }
            }
        }
        else
        {
            if(strategy == VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT)
            {
                // Forward order in m_Blocks - prefer blocks with smallest amount of free space.
                for(size_t blockIndex = 0; blockIndex < m_Blocks.size(); ++blockIndex )
                {
                    VmaDeviceMemoryBlock* const pCurrBlock = m_Blocks[blockIndex];
                    VMA_ASSERT(pCurrBlock);
                    VkResult res = AllocateFromBlock(
                        pCurrBlock,
                        currentFrameIndex,
                        size,
                        alignment,
                        allocFlagsCopy,
                        createInfo.pUserData,
                        suballocType,
                        strategy,
                        pAllocation);
                    if(res == VK_SUCCESS)
                    {
                        VMA_DEBUG_LOG("    Returned from existing block #%u", (uint32_t)blockIndex);
                        return VK_SUCCESS;
                    }
                }
            }
            else // WORST_FIT, FIRST_FIT
            {
                // Backward order in m_Blocks - prefer blocks with largest amount of free space.
                for(size_t blockIndex = m_Blocks.size(); blockIndex--; )
                {
                    VmaDeviceMemoryBlock* const pCurrBlock = m_Blocks[blockIndex];
                    VMA_ASSERT(pCurrBlock);
                    VkResult res = AllocateFromBlock(
                        pCurrBlock,
                        currentFrameIndex,
                        size,
                        alignment,
                        allocFlagsCopy,
                        createInfo.pUserData,
                        suballocType,
                        strategy,
                        pAllocation);
                    if(res == VK_SUCCESS)
                    {
                        VMA_DEBUG_LOG("    Returned from existing block #%u", (uint32_t)blockIndex);
                        return VK_SUCCESS;
                    }
                }
            }
        }

        // 2. Try to create new block.
        if(canCreateNewBlock)
        {
            // Calculate optimal size for new block.
            VkDeviceSize newBlockSize = m_PreferredBlockSize;
            uint32_t newBlockSizeShift = 0;
            const uint32_t NEW_BLOCK_SIZE_SHIFT_MAX = 3;

            if(!m_ExplicitBlockSize)
            {
                // Allocate 1/8, 1/4, 1/2 as first blocks.
                const VkDeviceSize maxExistingBlockSize = CalcMaxBlockSize();
                for(uint32_t i = 0; i < NEW_BLOCK_SIZE_SHIFT_MAX; ++i)
                {
                    const VkDeviceSize smallerNewBlockSize = newBlockSize / 2;
                    if(smallerNewBlockSize > maxExistingBlockSize && smallerNewBlockSize >= size * 2)
                    {
                        newBlockSize = smallerNewBlockSize;
                        ++newBlockSizeShift;
                    }
                    else
                    {
                        break;
                    }
                }
            }

            size_t newBlockIndex = 0;
            VkResult res = CreateBlock(newBlockSize, &newBlockIndex);
            // Allocation of this size failed? Try 1/2, 1/4, 1/8 of m_PreferredBlockSize.
            if(!m_ExplicitBlockSize)
            {
                while(res < 0 && newBlockSizeShift < NEW_BLOCK_SIZE_SHIFT_MAX)
                {
                    const VkDeviceSize smallerNewBlockSize = newBlockSize / 2;
                    if(smallerNewBlockSize >= size)
                    {
                        newBlockSize = smallerNewBlockSize;
                        ++newBlockSizeShift;
                        res = CreateBlock(newBlockSize, &newBlockIndex);
                    }
                    else
                    {
                        break;
                    }
                }
            }

            if(res == VK_SUCCESS)
            {
                VmaDeviceMemoryBlock* const pBlock = m_Blocks[newBlockIndex];
                VMA_ASSERT(pBlock->m_pMetadata->GetSize() >= size);

                res = AllocateFromBlock(
                    pBlock,
                    currentFrameIndex,
                    size,
                    alignment,
                    allocFlagsCopy,
                    createInfo.pUserData,
                    suballocType,
                    strategy,
                    pAllocation);
                if(res == VK_SUCCESS)
                {
                    VMA_DEBUG_LOG("    Created new block Size=%llu", newBlockSize);
                    return VK_SUCCESS;
                }
                else
                {
                    // Allocation from new block failed, possibly due to VMA_DEBUG_MARGIN or alignment.
                    return VK_ERROR_OUT_OF_DEVICE_MEMORY;
                }
            }
        }
    }

    // 3. Try to allocate from existing blocks with making other allocations lost.
    if(canMakeOtherLost)
    {
        uint32_t tryIndex = 0;
        for(; tryIndex < VMA_ALLOCATION_TRY_COUNT; ++tryIndex)
        {
            VmaDeviceMemoryBlock* pBestRequestBlock = VMA_NULL;
            VmaAllocationRequest bestRequest = {};
            VkDeviceSize bestRequestCost = VK_WHOLE_SIZE;

            // 1. Search existing allocations.
            if(strategy == VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT)
            {
                // Forward order in m_Blocks - prefer blocks with smallest amount of free space.
                for(size_t blockIndex = 0; blockIndex < m_Blocks.size(); ++blockIndex )
                {
                    VmaDeviceMemoryBlock* const pCurrBlock = m_Blocks[blockIndex];
                    VMA_ASSERT(pCurrBlock);
                    VmaAllocationRequest currRequest = {};
                    if(pCurrBlock->m_pMetadata->CreateAllocationRequest(
                        currentFrameIndex,
                        m_FrameInUseCount,
                        m_BufferImageGranularity,
                        size,
                        alignment,
                        (createInfo.flags & VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT) != 0,
                        suballocType,
                        canMakeOtherLost,
                        strategy,
                        &currRequest))
                    {
                        const VkDeviceSize currRequestCost = currRequest.CalcCost();
                        if(pBestRequestBlock == VMA_NULL ||
                            currRequestCost < bestRequestCost)
                        {
                            pBestRequestBlock = pCurrBlock;
                            bestRequest = currRequest;
                            bestRequestCost = currRequestCost;

                            if(bestRequestCost == 0)
                            {
                                break;
                            }
                        }
                    }
                }
            }
            else // WORST_FIT, FIRST_FIT
            {
                // Backward order in m_Blocks - prefer blocks with largest amount of free space.
                for(size_t blockIndex = m_Blocks.size(); blockIndex--; )
                {
                    VmaDeviceMemoryBlock* const pCurrBlock = m_Blocks[blockIndex];
                    VMA_ASSERT(pCurrBlock);
                    VmaAllocationRequest currRequest = {};
                    if(pCurrBlock->m_pMetadata->CreateAllocationRequest(
                        currentFrameIndex,
                        m_FrameInUseCount,
                        m_BufferImageGranularity,
                        size,
                        alignment,
                        (createInfo.flags & VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT) != 0,
                        suballocType,
                        canMakeOtherLost,
                        strategy,
                        &currRequest))
                    {
                        const VkDeviceSize currRequestCost = currRequest.CalcCost();
                        if(pBestRequestBlock == VMA_NULL ||
                            currRequestCost < bestRequestCost ||
                            strategy == VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT)
                        {
                            pBestRequestBlock = pCurrBlock;
                            bestRequest = currRequest;
                            bestRequestCost = currRequestCost;

                            if(bestRequestCost == 0 ||
                                strategy == VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT)
                            {
                                break;
                            }
                        }
                    }
                }
            }

            if(pBestRequestBlock != VMA_NULL)
            {
                if(mapped)
                {
                    VkResult res = pBestRequestBlock->Map(m_hAllocator, 1, VMA_NULL);
                    if(res != VK_SUCCESS)
                    {
                        return res;
                    }
                }

                if(pBestRequestBlock->m_pMetadata->MakeRequestedAllocationsLost(
                    currentFrameIndex,
                    m_FrameInUseCount,
                    &bestRequest))
                {
                    // We no longer have an empty Allocation.
                    if(pBestRequestBlock->m_pMetadata->IsEmpty())
                    {
                        m_HasEmptyBlock = false;
                    }
                    // Allocate from this pBlock.
                    *pAllocation = m_hAllocator->m_AllocationObjectAllocator.Allocate();
                    (*pAllocation)->Ctor(currentFrameIndex, isUserDataString);
                    pBestRequestBlock->m_pMetadata->Alloc(bestRequest, suballocType, size, *pAllocation);
                    (*pAllocation)->InitBlockAllocation(
                        pBestRequestBlock,
                        bestRequest.offset,
                        alignment,
                        size,
                        suballocType,
                        mapped,
                        (createInfo.flags & VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT) != 0);
                    VMA_HEAVY_ASSERT(pBestRequestBlock->Validate());
                    VMA_DEBUG_LOG("    Returned from existing block");
                    (*pAllocation)->SetUserData(m_hAllocator, createInfo.pUserData);
                    if(VMA_DEBUG_INITIALIZE_ALLOCATIONS)
                    {
                        m_hAllocator->FillAllocation(*pAllocation, VMA_ALLOCATION_FILL_PATTERN_CREATED);
                    }
                    if(IsCorruptionDetectionEnabled())
                    {
                        VkResult res = pBestRequestBlock->WriteMagicValueAroundAllocation(m_hAllocator, bestRequest.offset, size);
                        VMA_ASSERT(res == VK_SUCCESS && "Couldn't map block memory to write magic value.");
                    }
                    return VK_SUCCESS;
                }
                // else: Some allocations must have been touched while we are here. Next try.
            }
            else
            {
                // Could not find place in any of the blocks - break outer loop.
                break;
            }
        }
        /* Maximum number of tries exceeded - a very unlike event when many other
        threads are simultaneously touching allocations making it impossible to make
        lost at the same time as we try to allocate. */
        if(tryIndex == VMA_ALLOCATION_TRY_COUNT)
        {
            return VK_ERROR_TOO_MANY_OBJECTS;
        }
    }

    return VK_ERROR_OUT_OF_DEVICE_MEMORY;
}

void VmaBlockVector::Free(
    VmaAllocation hAllocation)
{
    VmaDeviceMemoryBlock* pBlockToDelete = VMA_NULL;

    // Scope for lock.
    {
        VmaMutexLockWrite lock(m_Mutex, m_hAllocator->m_UseMutex);

        VmaDeviceMemoryBlock* pBlock = hAllocation->GetBlock();

        if(IsCorruptionDetectionEnabled())
        {
            VkResult res = pBlock->ValidateMagicValueAroundAllocation(m_hAllocator, hAllocation->GetOffset(), hAllocation->GetSize());
            VMA_ASSERT(res == VK_SUCCESS && "Couldn't map block memory to validate magic value.");
        }

        if(hAllocation->IsPersistentMap())
        {
            pBlock->Unmap(m_hAllocator, 1);
        }

        pBlock->m_pMetadata->Free(hAllocation);
        VMA_HEAVY_ASSERT(pBlock->Validate());

        VMA_DEBUG_LOG("  Freed from MemoryTypeIndex=%u", m_MemoryTypeIndex);

        // pBlock became empty after this deallocation.
        if(pBlock->m_pMetadata->IsEmpty())
        {
            // Already has empty Allocation. We don't want to have two, so delete this one.
            if(m_HasEmptyBlock && m_Blocks.size() > m_MinBlockCount)
            {
                pBlockToDelete = pBlock;
                Remove(pBlock);
            }
            // We now have first empty block.
            else
            {
                m_HasEmptyBlock = true;
            }
        }
        // pBlock didn't become empty, but we have another empty block - find and free that one.
        // (This is optional, heuristics.)
        else if(m_HasEmptyBlock)
        {
            VmaDeviceMemoryBlock* pLastBlock = m_Blocks.back();
            if(pLastBlock->m_pMetadata->IsEmpty() && m_Blocks.size() > m_MinBlockCount)
            {
                pBlockToDelete = pLastBlock;
                m_Blocks.pop_back();
                m_HasEmptyBlock = false;
            }
        }

        IncrementallySortBlocks();
    }

    // Destruction of a free Allocation. Deferred until this point, outside of mutex
    // lock, for performance reason.
    if(pBlockToDelete != VMA_NULL)
    {
        VMA_DEBUG_LOG("    Deleted empty allocation");
        pBlockToDelete->Destroy(m_hAllocator);
        vma_delete(m_hAllocator, pBlockToDelete);
    }
}

VkDeviceSize VmaBlockVector::CalcMaxBlockSize() const
{
    VkDeviceSize result = 0;
    for(size_t i = m_Blocks.size(); i--; )
    {
        result = VMA_MAX(result, m_Blocks[i]->m_pMetadata->GetSize());
        if(result >= m_PreferredBlockSize)
        {
            break;
        }
    }
    return result;
}

void VmaBlockVector::Remove(VmaDeviceMemoryBlock* pBlock)
{
    for(uint32_t blockIndex = 0; blockIndex < m_Blocks.size(); ++blockIndex)
    {
        if(m_Blocks[blockIndex] == pBlock)
        {
            VmaVectorRemove(m_Blocks, blockIndex);
            return;
        }
    }
    VMA_ASSERT(0);
}

void VmaBlockVector::IncrementallySortBlocks()
{
    if(m_Algorithm != VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT)
    {
        // Bubble sort only until first swap.
        for(size_t i = 1; i < m_Blocks.size(); ++i)
        {
            if(m_Blocks[i - 1]->m_pMetadata->GetSumFreeSize() > m_Blocks[i]->m_pMetadata->GetSumFreeSize())
            {
                VMA_SWAP(m_Blocks[i - 1], m_Blocks[i]);
                return;
            }
        }
    }
}

VkResult VmaBlockVector::AllocateFromBlock(
    VmaDeviceMemoryBlock* pBlock,
    uint32_t currentFrameIndex,
    VkDeviceSize size,
    VkDeviceSize alignment,
    VmaAllocationCreateFlags allocFlags,
    void* pUserData,
    VmaSuballocationType suballocType,
    uint32_t strategy,
    VmaAllocation* pAllocation)
{
    VMA_ASSERT((allocFlags & VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT) == 0);
    const bool isUpperAddress = (allocFlags & VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT) != 0;
    const bool mapped = (allocFlags & VMA_ALLOCATION_CREATE_MAPPED_BIT) != 0;
    const bool isUserDataString = (allocFlags & VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT) != 0;

    VmaAllocationRequest currRequest = {};
    if(pBlock->m_pMetadata->CreateAllocationRequest(
        currentFrameIndex,
        m_FrameInUseCount,
        m_BufferImageGranularity,
        size,
        alignment,
        isUpperAddress,
        suballocType,
        false, // canMakeOtherLost
        strategy,
        &currRequest))
    {
        // Allocate from pCurrBlock.
        VMA_ASSERT(currRequest.itemsToMakeLostCount == 0);

        if(mapped)
        {
            VkResult res = pBlock->Map(m_hAllocator, 1, VMA_NULL);
            if(res != VK_SUCCESS)
            {
                return res;
            }
        }
            
        // We no longer have an empty Allocation.
        if(pBlock->m_pMetadata->IsEmpty())
        {
            m_HasEmptyBlock = false;
        }
            
        *pAllocation = m_hAllocator->m_AllocationObjectAllocator.Allocate();
        (*pAllocation)->Ctor(currentFrameIndex, isUserDataString);
        pBlock->m_pMetadata->Alloc(currRequest, suballocType, size, *pAllocation);
        (*pAllocation)->InitBlockAllocation(
            pBlock,
            currRequest.offset,
            alignment,
            size,
            suballocType,
            mapped,
            (allocFlags & VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT) != 0);
        VMA_HEAVY_ASSERT(pBlock->Validate());
        (*pAllocation)->SetUserData(m_hAllocator, pUserData);
        if(VMA_DEBUG_INITIALIZE_ALLOCATIONS)
        {
            m_hAllocator->FillAllocation(*pAllocation, VMA_ALLOCATION_FILL_PATTERN_CREATED);
        }
        if(IsCorruptionDetectionEnabled())
        {
            VkResult res = pBlock->WriteMagicValueAroundAllocation(m_hAllocator, currRequest.offset, size);
            VMA_ASSERT(res == VK_SUCCESS && "Couldn't map block memory to write magic value.");
        }
        return VK_SUCCESS;
    }
    return VK_ERROR_OUT_OF_DEVICE_MEMORY;
}

VkResult VmaBlockVector::CreateBlock(VkDeviceSize blockSize, size_t* pNewBlockIndex)
{
    VkMemoryAllocateInfo allocInfo = { VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO };
    allocInfo.memoryTypeIndex = m_MemoryTypeIndex;
    allocInfo.allocationSize = blockSize;
    VkDeviceMemory mem = VK_NULL_HANDLE;
    VkResult res = m_hAllocator->AllocateVulkanMemory(&allocInfo, &mem);
    if(res < 0)
    {
        return res;
    }

    // New VkDeviceMemory successfully created.

    // Create new Allocation for it.
    VmaDeviceMemoryBlock* const pBlock = vma_new(m_hAllocator, VmaDeviceMemoryBlock)(m_hAllocator);
    pBlock->Init(
        m_hAllocator,
        m_hParentPool,
        m_MemoryTypeIndex,
        mem,
        allocInfo.allocationSize,
        m_NextBlockId++,
        m_Algorithm);

    m_Blocks.push_back(pBlock);
    if(pNewBlockIndex != VMA_NULL)
    {
        *pNewBlockIndex = m_Blocks.size() - 1;
    }

    return VK_SUCCESS;
}

void VmaBlockVector::ApplyDefragmentationMovesCpu(
    class VmaBlockVectorDefragmentationContext* pDefragCtx,
    const VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves)
{
    const size_t blockCount = m_Blocks.size();
    const bool isNonCoherent = m_hAllocator->IsMemoryTypeNonCoherent(m_MemoryTypeIndex);

    enum BLOCK_FLAG
    {
        BLOCK_FLAG_USED = 0x00000001,
        BLOCK_FLAG_MAPPED_FOR_DEFRAGMENTATION = 0x00000002,
    };

    struct BlockInfo
    {
        uint32_t flags;
        void* pMappedData;
    };
    VmaVector< BlockInfo, VmaStlAllocator<BlockInfo> >
        blockInfo(blockCount, VmaStlAllocator<BlockInfo>(m_hAllocator->GetAllocationCallbacks()));
    memset(blockInfo.data(), 0, blockCount * sizeof(BlockInfo));

    // Go over all moves. Mark blocks that are used with BLOCK_FLAG_USED.
    const size_t moveCount = moves.size();
    for(size_t moveIndex = 0; moveIndex < moveCount; ++moveIndex)
    {
        const VmaDefragmentationMove& move = moves[moveIndex];
        blockInfo[move.srcBlockIndex].flags |= BLOCK_FLAG_USED;
        blockInfo[move.dstBlockIndex].flags |= BLOCK_FLAG_USED;
    }

    VMA_ASSERT(pDefragCtx->res == VK_SUCCESS);

    // Go over all blocks. Get mapped pointer or map if necessary.
    for(size_t blockIndex = 0; pDefragCtx->res == VK_SUCCESS && blockIndex < blockCount; ++blockIndex)
    {
        BlockInfo& currBlockInfo = blockInfo[blockIndex];
        VmaDeviceMemoryBlock* pBlock = m_Blocks[blockIndex];
        if((currBlockInfo.flags & BLOCK_FLAG_USED) != 0)
        {
            currBlockInfo.pMappedData = pBlock->GetMappedData();
            // It is not originally mapped - map it.
            if(currBlockInfo.pMappedData == VMA_NULL)
            {
                pDefragCtx->res = pBlock->Map(m_hAllocator, 1, &currBlockInfo.pMappedData);
                if(pDefragCtx->res == VK_SUCCESS)
                {
                    currBlockInfo.flags |= BLOCK_FLAG_MAPPED_FOR_DEFRAGMENTATION;
                }
            }
        }
    }

    // Go over all moves. Do actual data transfer.
    if(pDefragCtx->res == VK_SUCCESS)
    {
        const VkDeviceSize nonCoherentAtomSize = m_hAllocator->m_PhysicalDeviceProperties.limits.nonCoherentAtomSize;
        VkMappedMemoryRange memRange = { VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE };

        for(size_t moveIndex = 0; moveIndex < moveCount; ++moveIndex)
        {
            const VmaDefragmentationMove& move = moves[moveIndex];

            const BlockInfo& srcBlockInfo = blockInfo[move.srcBlockIndex];
            const BlockInfo& dstBlockInfo = blockInfo[move.dstBlockIndex];

            VMA_ASSERT(srcBlockInfo.pMappedData && dstBlockInfo.pMappedData);

            // Invalidate source.
            if(isNonCoherent)
            {
                VmaDeviceMemoryBlock* const pSrcBlock = m_Blocks[move.srcBlockIndex];
                memRange.memory = pSrcBlock->GetDeviceMemory();
                memRange.offset = VmaAlignDown(move.srcOffset, nonCoherentAtomSize);
                memRange.size = VMA_MIN(
                    VmaAlignUp(move.size + (move.srcOffset - memRange.offset), nonCoherentAtomSize),
                    pSrcBlock->m_pMetadata->GetSize() - memRange.offset);
                (*m_hAllocator->GetVulkanFunctions().vkInvalidateMappedMemoryRanges)(m_hAllocator->m_hDevice, 1, &memRange);
            }

            // THE PLACE WHERE ACTUAL DATA COPY HAPPENS.
            memmove(
                reinterpret_cast<char*>(dstBlockInfo.pMappedData) + move.dstOffset,
                reinterpret_cast<char*>(srcBlockInfo.pMappedData) + move.srcOffset,
                static_cast<size_t>(move.size));

            if(IsCorruptionDetectionEnabled())
            {
                VmaWriteMagicValue(dstBlockInfo.pMappedData, move.dstOffset - VMA_DEBUG_MARGIN);
                VmaWriteMagicValue(dstBlockInfo.pMappedData, move.dstOffset + move.size);
            }

            // Flush destination.
            if(isNonCoherent)
            {
                VmaDeviceMemoryBlock* const pDstBlock = m_Blocks[move.dstBlockIndex];
                memRange.memory = pDstBlock->GetDeviceMemory();
                memRange.offset = VmaAlignDown(move.dstOffset, nonCoherentAtomSize);
                memRange.size = VMA_MIN(
                    VmaAlignUp(move.size + (move.dstOffset - memRange.offset), nonCoherentAtomSize),
                    pDstBlock->m_pMetadata->GetSize() - memRange.offset);
                (*m_hAllocator->GetVulkanFunctions().vkFlushMappedMemoryRanges)(m_hAllocator->m_hDevice, 1, &memRange);
            }
        }
    }

    // Go over all blocks in reverse order. Unmap those that were mapped just for defragmentation.
    // Regardless of pCtx->res == VK_SUCCESS.
    for(size_t blockIndex = blockCount; blockIndex--; )
    {
        const BlockInfo& currBlockInfo = blockInfo[blockIndex];
        if((currBlockInfo.flags & BLOCK_FLAG_MAPPED_FOR_DEFRAGMENTATION) != 0)
        {
            VmaDeviceMemoryBlock* pBlock = m_Blocks[blockIndex];
            pBlock->Unmap(m_hAllocator, 1);
        }
    }
}

void VmaBlockVector::ApplyDefragmentationMovesGpu(
    class VmaBlockVectorDefragmentationContext* pDefragCtx,
    const VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
    VkCommandBuffer commandBuffer)
{
    const size_t blockCount = m_Blocks.size();

    pDefragCtx->blockContexts.resize(blockCount);
    memset(pDefragCtx->blockContexts.data(), 0, blockCount * sizeof(VmaBlockDefragmentationContext));

    // Go over all moves. Mark blocks that are used with BLOCK_FLAG_USED.
    const size_t moveCount = moves.size();
    for(size_t moveIndex = 0; moveIndex < moveCount; ++moveIndex)
    {
        const VmaDefragmentationMove& move = moves[moveIndex];
        pDefragCtx->blockContexts[move.srcBlockIndex].flags |= VmaBlockDefragmentationContext::BLOCK_FLAG_USED;
        pDefragCtx->blockContexts[move.dstBlockIndex].flags |= VmaBlockDefragmentationContext::BLOCK_FLAG_USED;
    }

    VMA_ASSERT(pDefragCtx->res == VK_SUCCESS);

    // Go over all blocks. Create and bind buffer for whole block if necessary.
    {
        VkBufferCreateInfo bufCreateInfo;
        VmaFillGpuDefragmentationBufferCreateInfo(bufCreateInfo);

        for(size_t blockIndex = 0; pDefragCtx->res == VK_SUCCESS && blockIndex < blockCount; ++blockIndex)
        {
            VmaBlockDefragmentationContext& currBlockCtx = pDefragCtx->blockContexts[blockIndex];
            VmaDeviceMemoryBlock* pBlock = m_Blocks[blockIndex];
            if((currBlockCtx.flags & VmaBlockDefragmentationContext::BLOCK_FLAG_USED) != 0)
            {
                bufCreateInfo.size = pBlock->m_pMetadata->GetSize();
                pDefragCtx->res = (*m_hAllocator->GetVulkanFunctions().vkCreateBuffer)(
                    m_hAllocator->m_hDevice, &bufCreateInfo, m_hAllocator->GetAllocationCallbacks(), &currBlockCtx.hBuffer);
                if(pDefragCtx->res == VK_SUCCESS)
                {
                    pDefragCtx->res = (*m_hAllocator->GetVulkanFunctions().vkBindBufferMemory)(
                        m_hAllocator->m_hDevice, currBlockCtx.hBuffer, pBlock->GetDeviceMemory(), 0);
                }
            }
        }
    }

    // Go over all moves. Post data transfer commands to command buffer.
    if(pDefragCtx->res == VK_SUCCESS)
    {
        for(size_t moveIndex = 0; moveIndex < moveCount; ++moveIndex)
        {
            const VmaDefragmentationMove& move = moves[moveIndex];

            const VmaBlockDefragmentationContext& srcBlockCtx = pDefragCtx->blockContexts[move.srcBlockIndex];
            const VmaBlockDefragmentationContext& dstBlockCtx = pDefragCtx->blockContexts[move.dstBlockIndex];

            VMA_ASSERT(srcBlockCtx.hBuffer && dstBlockCtx.hBuffer);

            VkBufferCopy region = {
                move.srcOffset,
                move.dstOffset,
                move.size };
            (*m_hAllocator->GetVulkanFunctions().vkCmdCopyBuffer)(
                commandBuffer, srcBlockCtx.hBuffer, dstBlockCtx.hBuffer, 1, &region);
        }
    }

    // Save buffers to defrag context for later destruction.
    if(pDefragCtx->res == VK_SUCCESS && moveCount > 0)
    {
        pDefragCtx->res = VK_NOT_READY;
    }
}

void VmaBlockVector::FreeEmptyBlocks(VmaDefragmentationStats* pDefragmentationStats)
{
    m_HasEmptyBlock = false;
    for(size_t blockIndex = m_Blocks.size(); blockIndex--; )
    {
        VmaDeviceMemoryBlock* pBlock = m_Blocks[blockIndex];
        if(pBlock->m_pMetadata->IsEmpty())
        {
            if(m_Blocks.size() > m_MinBlockCount)
            {
                if(pDefragmentationStats != VMA_NULL)
                {
                    ++pDefragmentationStats->deviceMemoryBlocksFreed;
                    pDefragmentationStats->bytesFreed += pBlock->m_pMetadata->GetSize();
                }

                VmaVectorRemove(m_Blocks, blockIndex);
                pBlock->Destroy(m_hAllocator);
                vma_delete(m_hAllocator, pBlock);
            }
            else
            {
                m_HasEmptyBlock = true;
            }
        }
    }
}

#if VMA_STATS_STRING_ENABLED

void VmaBlockVector::PrintDetailedMap(class VmaJsonWriter& json)
{
    VmaMutexLockRead lock(m_Mutex, m_hAllocator->m_UseMutex);

    json.BeginObject();

    if(m_IsCustomPool)
    {
        json.WriteString("MemoryTypeIndex");
        json.WriteNumber(m_MemoryTypeIndex);

        json.WriteString("BlockSize");
        json.WriteNumber(m_PreferredBlockSize);

        json.WriteString("BlockCount");
        json.BeginObject(true);
        if(m_MinBlockCount > 0)
        {
            json.WriteString("Min");
            json.WriteNumber((uint64_t)m_MinBlockCount);
        }
        if(m_MaxBlockCount < SIZE_MAX)
        {
            json.WriteString("Max");
            json.WriteNumber((uint64_t)m_MaxBlockCount);
        }
        json.WriteString("Cur");
        json.WriteNumber((uint64_t)m_Blocks.size());
        json.EndObject();

        if(m_FrameInUseCount > 0)
        {
            json.WriteString("FrameInUseCount");
            json.WriteNumber(m_FrameInUseCount);
        }

        if(m_Algorithm != 0)
        {
            json.WriteString("Algorithm");
            json.WriteString(VmaAlgorithmToStr(m_Algorithm));
        }
    }
    else
    {
        json.WriteString("PreferredBlockSize");
        json.WriteNumber(m_PreferredBlockSize);
    }

    json.WriteString("Blocks");
    json.BeginObject();
    for(size_t i = 0; i < m_Blocks.size(); ++i)
    {
        json.BeginString();
        json.ContinueString(m_Blocks[i]->GetId());
        json.EndString();

        m_Blocks[i]->m_pMetadata->PrintDetailedMap(json);
    }
    json.EndObject();

    json.EndObject();
}

#endif // #if VMA_STATS_STRING_ENABLED

void VmaBlockVector::Defragment(
    class VmaBlockVectorDefragmentationContext* pCtx,
    VmaDefragmentationStats* pStats,
    VkDeviceSize& maxCpuBytesToMove, uint32_t& maxCpuAllocationsToMove,
    VkDeviceSize& maxGpuBytesToMove, uint32_t& maxGpuAllocationsToMove,
    VkCommandBuffer commandBuffer)
{
    pCtx->res = VK_SUCCESS;
    
    const VkMemoryPropertyFlags memPropFlags =
        m_hAllocator->m_MemProps.memoryTypes[m_MemoryTypeIndex].propertyFlags;
    const bool isHostVisible = (memPropFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) != 0;
    const bool isHostCoherent = (memPropFlags & VK_MEMORY_PROPERTY_HOST_COHERENT_BIT) != 0;

    const bool canDefragmentOnCpu = maxCpuBytesToMove > 0 && maxCpuAllocationsToMove > 0 &&
        isHostVisible;
    const bool canDefragmentOnGpu = maxGpuBytesToMove > 0 && maxGpuAllocationsToMove > 0 &&
        !IsCorruptionDetectionEnabled() &&
        ((1u << m_MemoryTypeIndex) & m_hAllocator->GetGpuDefragmentationMemoryTypeBits()) != 0;

    // There are options to defragment this memory type.
    if(canDefragmentOnCpu || canDefragmentOnGpu)
    {
        bool defragmentOnGpu;
        // There is only one option to defragment this memory type.
        if(canDefragmentOnGpu != canDefragmentOnCpu)
        {
            defragmentOnGpu = canDefragmentOnGpu;
        }
        // Both options are available: Heuristics to choose the best one.
        else
        {
            defragmentOnGpu = (memPropFlags & VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT) != 0 ||
                m_hAllocator->IsIntegratedGpu();
        }

        bool overlappingMoveSupported = !defragmentOnGpu;

        if(m_hAllocator->m_UseMutex)
        {
            m_Mutex.LockWrite();
            pCtx->mutexLocked = true;
        }

        pCtx->Begin(overlappingMoveSupported);

        // Defragment.

        const VkDeviceSize maxBytesToMove = defragmentOnGpu ? maxGpuBytesToMove : maxCpuBytesToMove;
        const uint32_t maxAllocationsToMove = defragmentOnGpu ? maxGpuAllocationsToMove : maxCpuAllocationsToMove;
        VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> > moves = 
            VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >(VmaStlAllocator<VmaDefragmentationMove>(m_hAllocator->GetAllocationCallbacks()));
        pCtx->res = pCtx->GetAlgorithm()->Defragment(moves, maxBytesToMove, maxAllocationsToMove);

        // Accumulate statistics.
        if(pStats != VMA_NULL)
        {
            const VkDeviceSize bytesMoved = pCtx->GetAlgorithm()->GetBytesMoved();
            const uint32_t allocationsMoved = pCtx->GetAlgorithm()->GetAllocationsMoved();
            pStats->bytesMoved += bytesMoved;
            pStats->allocationsMoved += allocationsMoved;
            VMA_ASSERT(bytesMoved <= maxBytesToMove);
            VMA_ASSERT(allocationsMoved <= maxAllocationsToMove);
            if(defragmentOnGpu)
            {
                maxGpuBytesToMove -= bytesMoved;
                maxGpuAllocationsToMove -= allocationsMoved;
            }
            else
            {
                maxCpuBytesToMove -= bytesMoved;
                maxCpuAllocationsToMove -= allocationsMoved;
            }
        }
    
        if(pCtx->res >= VK_SUCCESS)
        {
            if(defragmentOnGpu)
            {
                ApplyDefragmentationMovesGpu(pCtx, moves, commandBuffer);
            }
            else
            {
                ApplyDefragmentationMovesCpu(pCtx, moves);
            }
        }
    }
}

void VmaBlockVector::DefragmentationEnd(
    class VmaBlockVectorDefragmentationContext* pCtx,
    VmaDefragmentationStats* pStats)
{
    // Destroy buffers.
    for(size_t blockIndex = pCtx->blockContexts.size(); blockIndex--; )
    {
        VmaBlockDefragmentationContext& blockCtx = pCtx->blockContexts[blockIndex];
        if(blockCtx.hBuffer)
        {
            (*m_hAllocator->GetVulkanFunctions().vkDestroyBuffer)(
                m_hAllocator->m_hDevice, blockCtx.hBuffer, m_hAllocator->GetAllocationCallbacks());
        }
    }

    if(pCtx->res >= VK_SUCCESS)
    {
        FreeEmptyBlocks(pStats);
    }

    if(pCtx->mutexLocked)
    {
        VMA_ASSERT(m_hAllocator->m_UseMutex);
        m_Mutex.UnlockWrite();
    }
}

size_t VmaBlockVector::CalcAllocationCount() const
{
    size_t result = 0;
    for(size_t i = 0; i < m_Blocks.size(); ++i)
    {
        result += m_Blocks[i]->m_pMetadata->GetAllocationCount();
    }
    return result;
}

bool VmaBlockVector::IsBufferImageGranularityConflictPossible() const
{
    if(m_BufferImageGranularity == 1)
    {
        return false;
    }
    VmaSuballocationType lastSuballocType = VMA_SUBALLOCATION_TYPE_FREE;
    for(size_t i = 0, count = m_Blocks.size(); i < count; ++i)
    {
        VmaDeviceMemoryBlock* const pBlock = m_Blocks[i];
        VMA_ASSERT(m_Algorithm == 0);
        VmaBlockMetadata_Generic* const pMetadata = (VmaBlockMetadata_Generic*)pBlock->m_pMetadata;
        if(pMetadata->IsBufferImageGranularityConflictPossible(m_BufferImageGranularity, lastSuballocType))
        {
            return true;
        }
    }
    return false;
}

void VmaBlockVector::MakePoolAllocationsLost(
    uint32_t currentFrameIndex,
    size_t* pLostAllocationCount)
{
    VmaMutexLockWrite lock(m_Mutex, m_hAllocator->m_UseMutex);
    size_t lostAllocationCount = 0;
    for(uint32_t blockIndex = 0; blockIndex < m_Blocks.size(); ++blockIndex)
    {
        VmaDeviceMemoryBlock* const pBlock = m_Blocks[blockIndex];
        VMA_ASSERT(pBlock);
        lostAllocationCount += pBlock->m_pMetadata->MakeAllocationsLost(currentFrameIndex, m_FrameInUseCount);
    }
    if(pLostAllocationCount != VMA_NULL)
    {
        *pLostAllocationCount = lostAllocationCount;
    }
}

VkResult VmaBlockVector::CheckCorruption()
{
    if(!IsCorruptionDetectionEnabled())
    {
        return VK_ERROR_FEATURE_NOT_PRESENT;
    }

    VmaMutexLockRead lock(m_Mutex, m_hAllocator->m_UseMutex);
    for(uint32_t blockIndex = 0; blockIndex < m_Blocks.size(); ++blockIndex)
    {
        VmaDeviceMemoryBlock* const pBlock = m_Blocks[blockIndex];
        VMA_ASSERT(pBlock);
        VkResult res = pBlock->CheckCorruption(m_hAllocator);
        if(res != VK_SUCCESS)
        {
            return res;
        }
    }
    return VK_SUCCESS;
}

void VmaBlockVector::AddStats(VmaStats* pStats)
{
    const uint32_t memTypeIndex = m_MemoryTypeIndex;
    const uint32_t memHeapIndex = m_hAllocator->MemoryTypeIndexToHeapIndex(memTypeIndex);

    VmaMutexLockRead lock(m_Mutex, m_hAllocator->m_UseMutex);

    for(uint32_t blockIndex = 0; blockIndex < m_Blocks.size(); ++blockIndex)
    {
        const VmaDeviceMemoryBlock* const pBlock = m_Blocks[blockIndex];
        VMA_ASSERT(pBlock);
        VMA_HEAVY_ASSERT(pBlock->Validate());
        VmaStatInfo allocationStatInfo;
        pBlock->m_pMetadata->CalcAllocationStatInfo(allocationStatInfo);
        VmaAddStatInfo(pStats->total, allocationStatInfo);
        VmaAddStatInfo(pStats->memoryType[memTypeIndex], allocationStatInfo);
        VmaAddStatInfo(pStats->memoryHeap[memHeapIndex], allocationStatInfo);
    }
}

// VmaDefragmentationAlgorithm_Generic members definition

VmaDefragmentationAlgorithm_Generic::VmaDefragmentationAlgorithm_Generic(
    VmaAllocator hAllocator,
    VmaBlockVector* pBlockVector,
    uint32_t currentFrameIndex,
    bool overlappingMoveSupported) :
    VmaDefragmentationAlgorithm(hAllocator, pBlockVector, currentFrameIndex),
    m_AllocationCount(0),
    m_AllAllocations(false),
    m_BytesMoved(0),
    m_AllocationsMoved(0),
    m_Blocks(VmaStlAllocator<BlockInfo*>(hAllocator->GetAllocationCallbacks()))
{
    // Create block info for each block.
    const size_t blockCount = m_pBlockVector->m_Blocks.size();
    for(size_t blockIndex = 0; blockIndex < blockCount; ++blockIndex)
    {
        BlockInfo* pBlockInfo = vma_new(m_hAllocator, BlockInfo)(m_hAllocator->GetAllocationCallbacks());
        pBlockInfo->m_OriginalBlockIndex = blockIndex;
        pBlockInfo->m_pBlock = m_pBlockVector->m_Blocks[blockIndex];
        m_Blocks.push_back(pBlockInfo);
    }

    // Sort them by m_pBlock pointer value.
    VMA_SORT(m_Blocks.begin(), m_Blocks.end(), BlockPointerLess());
}

VmaDefragmentationAlgorithm_Generic::~VmaDefragmentationAlgorithm_Generic()
{
    for(size_t i = m_Blocks.size(); i--; )
    {
        vma_delete(m_hAllocator, m_Blocks[i]);
    }
}

void VmaDefragmentationAlgorithm_Generic::AddAllocation(VmaAllocation hAlloc, VkBool32* pChanged)
{
    // Now as we are inside VmaBlockVector::m_Mutex, we can make final check if this allocation was not lost.
    if(hAlloc->GetLastUseFrameIndex() != VMA_FRAME_INDEX_LOST)
    {
        VmaDeviceMemoryBlock* pBlock = hAlloc->GetBlock();
        BlockInfoVector::iterator it = VmaBinaryFindFirstNotLess(m_Blocks.begin(), m_Blocks.end(), pBlock, BlockPointerLess());
        if(it != m_Blocks.end() && (*it)->m_pBlock == pBlock)
        {
            AllocationInfo allocInfo = AllocationInfo(hAlloc, pChanged);
            (*it)->m_Allocations.push_back(allocInfo);
        }
        else
        {
            VMA_ASSERT(0);
        }

        ++m_AllocationCount;
    }
}

VkResult VmaDefragmentationAlgorithm_Generic::DefragmentRound(
    VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
    VkDeviceSize maxBytesToMove,
    uint32_t maxAllocationsToMove)
{
    if(m_Blocks.empty())
    {
        return VK_SUCCESS;
    }

    // This is a choice based on research.
    // Option 1:
    uint32_t strategy = VMA_ALLOCATION_CREATE_STRATEGY_MIN_TIME_BIT;
    // Option 2:
    //uint32_t strategy = VMA_ALLOCATION_CREATE_STRATEGY_MIN_MEMORY_BIT;
    // Option 3:
    //uint32_t strategy = VMA_ALLOCATION_CREATE_STRATEGY_MIN_FRAGMENTATION_BIT;

    size_t srcBlockMinIndex = 0;
    // When FAST_ALGORITHM, move allocations from only last out of blocks that contain non-movable allocations.
    /*
    if(m_AlgorithmFlags & VMA_DEFRAGMENTATION_FAST_ALGORITHM_BIT)
    {
        const size_t blocksWithNonMovableCount = CalcBlocksWithNonMovableCount();
        if(blocksWithNonMovableCount > 0)
        {
            srcBlockMinIndex = blocksWithNonMovableCount - 1;
        }
    }
    */

    size_t srcBlockIndex = m_Blocks.size() - 1;
    size_t srcAllocIndex = SIZE_MAX;
    for(;;)
    {
        // 1. Find next allocation to move.
        // 1.1. Start from last to first m_Blocks - they are sorted from most "destination" to most "source".
        // 1.2. Then start from last to first m_Allocations.
        while(srcAllocIndex >= m_Blocks[srcBlockIndex]->m_Allocations.size())
        {
            if(m_Blocks[srcBlockIndex]->m_Allocations.empty())
            {
                // Finished: no more allocations to process.
                if(srcBlockIndex == srcBlockMinIndex)
                {
                    return VK_SUCCESS;
                }
                else
                {
                    --srcBlockIndex;
                    srcAllocIndex = SIZE_MAX;
                }
            }
            else
            {
                srcAllocIndex = m_Blocks[srcBlockIndex]->m_Allocations.size() - 1;
            }
        }
        
        BlockInfo* pSrcBlockInfo = m_Blocks[srcBlockIndex];
        AllocationInfo& allocInfo = pSrcBlockInfo->m_Allocations[srcAllocIndex];

        const VkDeviceSize size = allocInfo.m_hAllocation->GetSize();
        const VkDeviceSize srcOffset = allocInfo.m_hAllocation->GetOffset();
        const VkDeviceSize alignment = allocInfo.m_hAllocation->GetAlignment();
        const VmaSuballocationType suballocType = allocInfo.m_hAllocation->GetSuballocationType();

        // 2. Try to find new place for this allocation in preceding or current block.
        for(size_t dstBlockIndex = 0; dstBlockIndex <= srcBlockIndex; ++dstBlockIndex)
        {
            BlockInfo* pDstBlockInfo = m_Blocks[dstBlockIndex];
            VmaAllocationRequest dstAllocRequest;
            if(pDstBlockInfo->m_pBlock->m_pMetadata->CreateAllocationRequest(
                m_CurrentFrameIndex,
                m_pBlockVector->GetFrameInUseCount(),
                m_pBlockVector->GetBufferImageGranularity(),
                size,
                alignment,
                false, // upperAddress
                suballocType,
                false, // canMakeOtherLost
                strategy,
                &dstAllocRequest) &&
            MoveMakesSense(
                dstBlockIndex, dstAllocRequest.offset, srcBlockIndex, srcOffset))
            {
                VMA_ASSERT(dstAllocRequest.itemsToMakeLostCount == 0);

                // Reached limit on number of allocations or bytes to move.
                if((m_AllocationsMoved + 1 > maxAllocationsToMove) ||
                    (m_BytesMoved + size > maxBytesToMove))
                {
                    return VK_SUCCESS;
                }

                VmaDefragmentationMove move;
                move.srcBlockIndex = pSrcBlockInfo->m_OriginalBlockIndex;
                move.dstBlockIndex = pDstBlockInfo->m_OriginalBlockIndex;
                move.srcOffset = srcOffset;
                move.dstOffset = dstAllocRequest.offset;
                move.size = size;
                moves.push_back(move);

                pDstBlockInfo->m_pBlock->m_pMetadata->Alloc(
                    dstAllocRequest,
                    suballocType,
                    size,
                    allocInfo.m_hAllocation);
                pSrcBlockInfo->m_pBlock->m_pMetadata->FreeAtOffset(srcOffset);
                
                allocInfo.m_hAllocation->ChangeBlockAllocation(m_hAllocator, pDstBlockInfo->m_pBlock, dstAllocRequest.offset);

                if(allocInfo.m_pChanged != VMA_NULL)
                {
                    *allocInfo.m_pChanged = VK_TRUE;
                }

                ++m_AllocationsMoved;
                m_BytesMoved += size;

                VmaVectorRemove(pSrcBlockInfo->m_Allocations, srcAllocIndex);

                break;
            }
        }

        // If not processed, this allocInfo remains in pBlockInfo->m_Allocations for next round.

        if(srcAllocIndex > 0)
        {
            --srcAllocIndex;
        }
        else
        {
            if(srcBlockIndex > 0)
            {
                --srcBlockIndex;
                srcAllocIndex = SIZE_MAX;
            }
            else
            {
                return VK_SUCCESS;
            }
        }
    }
}

size_t VmaDefragmentationAlgorithm_Generic::CalcBlocksWithNonMovableCount() const
{
    size_t result = 0;
    for(size_t i = 0; i < m_Blocks.size(); ++i)
    {
        if(m_Blocks[i]->m_HasNonMovableAllocations)
        {
            ++result;
        }
    }
    return result;
}

VkResult VmaDefragmentationAlgorithm_Generic::Defragment(
    VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
    VkDeviceSize maxBytesToMove,
    uint32_t maxAllocationsToMove)
{
    if(!m_AllAllocations && m_AllocationCount == 0)
    {
        return VK_SUCCESS;
    }

    const size_t blockCount = m_Blocks.size();
    for(size_t blockIndex = 0; blockIndex < blockCount; ++blockIndex)
    {
        BlockInfo* pBlockInfo = m_Blocks[blockIndex];

        if(m_AllAllocations)
        {
            VmaBlockMetadata_Generic* pMetadata = (VmaBlockMetadata_Generic*)pBlockInfo->m_pBlock->m_pMetadata;
            for(VmaSuballocationList::const_iterator it = pMetadata->m_Suballocations.begin();
                it != pMetadata->m_Suballocations.end();
                ++it)
            {
                if(it->type != VMA_SUBALLOCATION_TYPE_FREE)
                {
                    AllocationInfo allocInfo = AllocationInfo(it->hAllocation, VMA_NULL);
                    pBlockInfo->m_Allocations.push_back(allocInfo);
                }
            }
        }

        pBlockInfo->CalcHasNonMovableAllocations();
        
        // This is a choice based on research.
        // Option 1:
        pBlockInfo->SortAllocationsByOffsetDescending();
        // Option 2:
        //pBlockInfo->SortAllocationsBySizeDescending();
    }

    // Sort m_Blocks this time by the main criterium, from most "destination" to most "source" blocks.
    VMA_SORT(m_Blocks.begin(), m_Blocks.end(), BlockInfoCompareMoveDestination());

    // This is a choice based on research.
    const uint32_t roundCount = 2;

    // Execute defragmentation rounds (the main part).
    VkResult result = VK_SUCCESS;
    for(uint32_t round = 0; (round < roundCount) && (result == VK_SUCCESS); ++round)
    {
        result = DefragmentRound(moves, maxBytesToMove, maxAllocationsToMove);
    }

    return result;
}

bool VmaDefragmentationAlgorithm_Generic::MoveMakesSense(
        size_t dstBlockIndex, VkDeviceSize dstOffset,
        size_t srcBlockIndex, VkDeviceSize srcOffset)
{
    if(dstBlockIndex < srcBlockIndex)
    {
        return true;
    }
    if(dstBlockIndex > srcBlockIndex)
    {
        return false;
    }
    if(dstOffset < srcOffset)
    {
        return true;
    }
    return false;
}

// VmaDefragmentationAlgorithm_Fast

VmaDefragmentationAlgorithm_Fast::VmaDefragmentationAlgorithm_Fast(
    VmaAllocator hAllocator,
    VmaBlockVector* pBlockVector,
    uint32_t currentFrameIndex,
    bool overlappingMoveSupported) :
    VmaDefragmentationAlgorithm(hAllocator, pBlockVector, currentFrameIndex),
    m_OverlappingMoveSupported(overlappingMoveSupported),
    m_AllocationCount(0),
    m_AllAllocations(false),
    m_BytesMoved(0),
    m_AllocationsMoved(0),
    m_BlockInfos(VmaStlAllocator<BlockInfo>(hAllocator->GetAllocationCallbacks()))
{
    VMA_ASSERT(VMA_DEBUG_MARGIN == 0);

}

VmaDefragmentationAlgorithm_Fast::~VmaDefragmentationAlgorithm_Fast()
{
}

VkResult VmaDefragmentationAlgorithm_Fast::Defragment(
    VmaVector< VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove> >& moves,
    VkDeviceSize maxBytesToMove,
    uint32_t maxAllocationsToMove)
{
    VMA_ASSERT(m_AllAllocations || m_pBlockVector->CalcAllocationCount() == m_AllocationCount);

    const size_t blockCount = m_pBlockVector->GetBlockCount();
    if(blockCount == 0 || maxBytesToMove == 0 || maxAllocationsToMove == 0)
    {
        return VK_SUCCESS;
    }

    PreprocessMetadata();

    // Sort blocks in order from most destination.

    m_BlockInfos.resize(blockCount);
    for(size_t i = 0; i < blockCount; ++i)
    {
        m_BlockInfos[i].origBlockIndex = i;
    }

    VMA_SORT(m_BlockInfos.begin(), m_BlockInfos.end(), [this](const BlockInfo& lhs, const BlockInfo& rhs) -> bool {
        return m_pBlockVector->GetBlock(lhs.origBlockIndex)->m_pMetadata->GetSumFreeSize() <
            m_pBlockVector->GetBlock(rhs.origBlockIndex)->m_pMetadata->GetSumFreeSize();
    });

    // THE MAIN ALGORITHM

    FreeSpaceDatabase freeSpaceDb;

    size_t dstBlockInfoIndex = 0;
    size_t dstOrigBlockIndex = m_BlockInfos[dstBlockInfoIndex].origBlockIndex;
    VmaDeviceMemoryBlock* pDstBlock = m_pBlockVector->GetBlock(dstOrigBlockIndex);
    VmaBlockMetadata_Generic* pDstMetadata = (VmaBlockMetadata_Generic*)pDstBlock->m_pMetadata;
    VkDeviceSize dstBlockSize = pDstMetadata->GetSize();
    VkDeviceSize dstOffset = 0;

    bool end = false;
    for(size_t srcBlockInfoIndex = 0; !end && srcBlockInfoIndex < blockCount; ++srcBlockInfoIndex)
    {
        const size_t srcOrigBlockIndex = m_BlockInfos[srcBlockInfoIndex].origBlockIndex;
        VmaDeviceMemoryBlock* const pSrcBlock = m_pBlockVector->GetBlock(srcOrigBlockIndex);
        VmaBlockMetadata_Generic* const pSrcMetadata = (VmaBlockMetadata_Generic*)pSrcBlock->m_pMetadata;
        for(VmaSuballocationList::iterator srcSuballocIt = pSrcMetadata->m_Suballocations.begin();
            !end && srcSuballocIt != pSrcMetadata->m_Suballocations.end(); )
        {
            VmaAllocation_T* const pAlloc = srcSuballocIt->hAllocation;
            const VkDeviceSize srcAllocAlignment = pAlloc->GetAlignment();
            const VkDeviceSize srcAllocSize = srcSuballocIt->size;
            if(m_AllocationsMoved == maxAllocationsToMove ||
                m_BytesMoved + srcAllocSize > maxBytesToMove)
            {
                end = true;
                break;
            }
            const VkDeviceSize srcAllocOffset = srcSuballocIt->offset;

            // Try to place it in one of free spaces from the database.
            size_t freeSpaceInfoIndex;
            VkDeviceSize dstAllocOffset;
            if(freeSpaceDb.Fetch(srcAllocAlignment, srcAllocSize,
                freeSpaceInfoIndex, dstAllocOffset))
            {
                size_t freeSpaceOrigBlockIndex = m_BlockInfos[freeSpaceInfoIndex].origBlockIndex;
                VmaDeviceMemoryBlock* pFreeSpaceBlock = m_pBlockVector->GetBlock(freeSpaceOrigBlockIndex);
                VmaBlockMetadata_Generic* pFreeSpaceMetadata = (VmaBlockMetadata_Generic*)pFreeSpaceBlock->m_pMetadata;

                // Same block
                if(freeSpaceInfoIndex == srcBlockInfoIndex)
                {
                    VMA_ASSERT(dstAllocOffset <= srcAllocOffset);

                    // MOVE OPTION 1: Move the allocation inside the same block by decreasing offset.

                    VmaSuballocation suballoc = *srcSuballocIt;
                    suballoc.offset = dstAllocOffset;
                    suballoc.hAllocation->ChangeOffset(dstAllocOffset);
                    m_BytesMoved += srcAllocSize;
                    ++m_AllocationsMoved;
                    
                    VmaSuballocationList::iterator nextSuballocIt = srcSuballocIt;
                    ++nextSuballocIt;
                    pSrcMetadata->m_Suballocations.erase(srcSuballocIt);
                    srcSuballocIt = nextSuballocIt;

                    InsertSuballoc(pFreeSpaceMetadata, suballoc);

                    VmaDefragmentationMove move = {
                        srcOrigBlockIndex, freeSpaceOrigBlockIndex,
                        srcAllocOffset, dstAllocOffset,
                        srcAllocSize };
                    moves.push_back(move);
                }
                // Different block
                else
                {
                    // MOVE OPTION 2: Move the allocation to a different block.

                    VMA_ASSERT(freeSpaceInfoIndex < srcBlockInfoIndex);

                    VmaSuballocation suballoc = *srcSuballocIt;
                    suballoc.offset = dstAllocOffset;
                    suballoc.hAllocation->ChangeBlockAllocation(m_hAllocator, pFreeSpaceBlock, dstAllocOffset);
                    m_BytesMoved += srcAllocSize;
                    ++m_AllocationsMoved;

                    VmaSuballocationList::iterator nextSuballocIt = srcSuballocIt;
                    ++nextSuballocIt;
                    pSrcMetadata->m_Suballocations.erase(srcSuballocIt);
                    srcSuballocIt = nextSuballocIt;

                    InsertSuballoc(pFreeSpaceMetadata, suballoc);

                    VmaDefragmentationMove move = {
                        srcOrigBlockIndex, freeSpaceOrigBlockIndex,
                        srcAllocOffset, dstAllocOffset,
                        srcAllocSize };
                    moves.push_back(move);
                }
            }
            else
            {
                dstAllocOffset = VmaAlignUp(dstOffset, srcAllocAlignment);

                // If the allocation doesn't fit before the end of dstBlock, forward to next block.
                while(dstBlockInfoIndex < srcBlockInfoIndex &&
                    dstAllocOffset + srcAllocSize > dstBlockSize)
                {
                    // But before that, register remaining free space at the end of dst block.
                    freeSpaceDb.Register(dstBlockInfoIndex, dstOffset, dstBlockSize - dstOffset);

                    ++dstBlockInfoIndex;
                    dstOrigBlockIndex = m_BlockInfos[dstBlockInfoIndex].origBlockIndex;
                    pDstBlock = m_pBlockVector->GetBlock(dstOrigBlockIndex);
                    pDstMetadata = (VmaBlockMetadata_Generic*)pDstBlock->m_pMetadata;
                    dstBlockSize = pDstMetadata->GetSize();
                    dstOffset = 0;
                    dstAllocOffset = 0;
                }

                // Same block
                if(dstBlockInfoIndex == srcBlockInfoIndex)
                {
                    VMA_ASSERT(dstAllocOffset <= srcAllocOffset);

                    const bool overlap = dstAllocOffset + srcAllocSize > srcAllocOffset;

                    bool skipOver = overlap;
                    if(overlap && m_OverlappingMoveSupported && dstAllocOffset < srcAllocOffset)
                    {
                        // If destination and source place overlap, skip if it would move it
                        // by only < 1/64 of its size.
                        skipOver = (srcAllocOffset - dstAllocOffset) * 64 < srcAllocSize;
                    }

                    if(skipOver)
                    {
                        freeSpaceDb.Register(dstBlockInfoIndex, dstOffset, srcAllocOffset - dstOffset);

                        dstOffset = srcAllocOffset + srcAllocSize;
                        ++srcSuballocIt;
                    }
                    // MOVE OPTION 1: Move the allocation inside the same block by decreasing offset.
                    else
                    {
                        srcSuballocIt->offset = dstAllocOffset;
                        srcSuballocIt->hAllocation->ChangeOffset(dstAllocOffset);
                        dstOffset = dstAllocOffset + srcAllocSize;
                        m_BytesMoved += srcAllocSize;
                        ++m_AllocationsMoved;
                        ++srcSuballocIt;
                        VmaDefragmentationMove move = {
                            srcOrigBlockIndex, dstOrigBlockIndex,
                            srcAllocOffset, dstAllocOffset,
                            srcAllocSize };
                        moves.push_back(move);
                    }
                }
                // Different block
                else
                {
                    // MOVE OPTION 2: Move the allocation to a different block.

                    VMA_ASSERT(dstBlockInfoIndex < srcBlockInfoIndex);
                    VMA_ASSERT(dstAllocOffset + srcAllocSize <= dstBlockSize);

                    VmaSuballocation suballoc = *srcSuballocIt;
                    suballoc.offset = dstAllocOffset;
                    suballoc.hAllocation->ChangeBlockAllocation(m_hAllocator, pDstBlock, dstAllocOffset);
                    dstOffset = dstAllocOffset + srcAllocSize;
                    m_BytesMoved += srcAllocSize;
                    ++m_AllocationsMoved;

                    VmaSuballocationList::iterator nextSuballocIt = srcSuballocIt;
                    ++nextSuballocIt;
                    pSrcMetadata->m_Suballocations.erase(srcSuballocIt);
                    srcSuballocIt = nextSuballocIt;

                    pDstMetadata->m_Suballocations.push_back(suballoc);

                    VmaDefragmentationMove move = {
                        srcOrigBlockIndex, dstOrigBlockIndex,
                        srcAllocOffset, dstAllocOffset,
                        srcAllocSize };
                    moves.push_back(move);
                }
            }
        }
    }

    m_BlockInfos.clear();
    
    PostprocessMetadata();

    return VK_SUCCESS;
}

void VmaDefragmentationAlgorithm_Fast::PreprocessMetadata()
{
    const size_t blockCount = m_pBlockVector->GetBlockCount();
    for(size_t blockIndex = 0; blockIndex < blockCount; ++blockIndex)
    {
        VmaBlockMetadata_Generic* const pMetadata =
            (VmaBlockMetadata_Generic*)m_pBlockVector->GetBlock(blockIndex)->m_pMetadata;
        pMetadata->m_FreeCount = 0;
        pMetadata->m_SumFreeSize = pMetadata->GetSize();
        pMetadata->m_FreeSuballocationsBySize.clear();
        for(VmaSuballocationList::iterator it = pMetadata->m_Suballocations.begin();
            it != pMetadata->m_Suballocations.end(); )
        {
            if(it->type == VMA_SUBALLOCATION_TYPE_FREE)
            {
                VmaSuballocationList::iterator nextIt = it;
                ++nextIt;
                pMetadata->m_Suballocations.erase(it);
                it = nextIt;
            }
            else
            {
                ++it;
            }
        }
    }
}

void VmaDefragmentationAlgorithm_Fast::PostprocessMetadata()
{
    const size_t blockCount = m_pBlockVector->GetBlockCount();
    for(size_t blockIndex = 0; blockIndex < blockCount; ++blockIndex)
    {
        VmaBlockMetadata_Generic* const pMetadata =
            (VmaBlockMetadata_Generic*)m_pBlockVector->GetBlock(blockIndex)->m_pMetadata;
        const VkDeviceSize blockSize = pMetadata->GetSize();
        
        // No allocations in this block - entire area is free.
        if(pMetadata->m_Suballocations.empty())
        {
            pMetadata->m_FreeCount = 1;
            //pMetadata->m_SumFreeSize is already set to blockSize.
            VmaSuballocation suballoc = {
                0, // offset
                blockSize, // size
                VMA_NULL, // hAllocation
                VMA_SUBALLOCATION_TYPE_FREE };
            pMetadata->m_Suballocations.push_back(suballoc);
            pMetadata->RegisterFreeSuballocation(pMetadata->m_Suballocations.begin());
        }
        // There are some allocations in this block.
        else
        {
            VkDeviceSize offset = 0;
            VmaSuballocationList::iterator it;
            for(it = pMetadata->m_Suballocations.begin();
                it != pMetadata->m_Suballocations.end();
                ++it)
            {
                VMA_ASSERT(it->type != VMA_SUBALLOCATION_TYPE_FREE);
                VMA_ASSERT(it->offset >= offset);

                // Need to insert preceding free space.
                if(it->offset > offset)
                {
                    ++pMetadata->m_FreeCount;
                    const VkDeviceSize freeSize = it->offset - offset;
                    VmaSuballocation suballoc = {
                        offset, // offset
                        freeSize, // size
                        VMA_NULL, // hAllocation
                        VMA_SUBALLOCATION_TYPE_FREE };
                    VmaSuballocationList::iterator precedingFreeIt = pMetadata->m_Suballocations.insert(it, suballoc);
                    if(freeSize >= VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER)
                    {
                        pMetadata->m_FreeSuballocationsBySize.push_back(precedingFreeIt);
                    }
                }

                pMetadata->m_SumFreeSize -= it->size;
                offset = it->offset + it->size;
            }

            // Need to insert trailing free space.
            if(offset < blockSize)
            {
                ++pMetadata->m_FreeCount;
                const VkDeviceSize freeSize = blockSize - offset;
                VmaSuballocation suballoc = {
                    offset, // offset
                    freeSize, // size
                    VMA_NULL, // hAllocation
                    VMA_SUBALLOCATION_TYPE_FREE };
                VMA_ASSERT(it == pMetadata->m_Suballocations.end());
                VmaSuballocationList::iterator trailingFreeIt = pMetadata->m_Suballocations.insert(it, suballoc);
                if(freeSize > VMA_MIN_FREE_SUBALLOCATION_SIZE_TO_REGISTER)
                {
                    pMetadata->m_FreeSuballocationsBySize.push_back(trailingFreeIt);
                }
            }

            VMA_SORT(
                pMetadata->m_FreeSuballocationsBySize.begin(),
                pMetadata->m_FreeSuballocationsBySize.end(),
                VmaSuballocationItemSizeLess());
        }

        VMA_HEAVY_ASSERT(pMetadata->Validate());
    }
}

void VmaDefragmentationAlgorithm_Fast::InsertSuballoc(VmaBlockMetadata_Generic* pMetadata, const VmaSuballocation& suballoc)
{
    // TODO: Optimize somehow. Remember iterator instead of searching for it linearly.
    VmaSuballocationList::iterator it = pMetadata->m_Suballocations.begin();
    while(it != pMetadata->m_Suballocations.end())
    {
        if(it->offset < suballoc.offset)
        {
            ++it;
        }
    }
    pMetadata->m_Suballocations.insert(it, suballoc);
}

// VmaBlockVectorDefragmentationContext

VmaBlockVectorDefragmentationContext::VmaBlockVectorDefragmentationContext(
    VmaAllocator hAllocator,
    VmaPool hCustomPool,
    VmaBlockVector* pBlockVector,
    uint32_t currFrameIndex,
    uint32_t algorithmFlags) :
    res(VK_SUCCESS),
    mutexLocked(false),
    blockContexts(VmaStlAllocator<VmaBlockDefragmentationContext>(hAllocator->GetAllocationCallbacks())),
    m_hAllocator(hAllocator),
    m_hCustomPool(hCustomPool),
    m_pBlockVector(pBlockVector),
    m_CurrFrameIndex(currFrameIndex),
    m_AlgorithmFlags(algorithmFlags),
    m_pAlgorithm(VMA_NULL),
    m_Allocations(VmaStlAllocator<AllocInfo>(hAllocator->GetAllocationCallbacks())),
    m_AllAllocations(false)
{
}

VmaBlockVectorDefragmentationContext::~VmaBlockVectorDefragmentationContext()
{
    vma_delete(m_hAllocator, m_pAlgorithm);
}

void VmaBlockVectorDefragmentationContext::AddAllocation(VmaAllocation hAlloc, VkBool32* pChanged)
{
    AllocInfo info = { hAlloc, pChanged };
    m_Allocations.push_back(info);
}

void VmaBlockVectorDefragmentationContext::Begin(bool overlappingMoveSupported)
{
    const bool allAllocations = m_AllAllocations ||
        m_Allocations.size() == m_pBlockVector->CalcAllocationCount();

    /********************************
    HERE IS THE CHOICE OF DEFRAGMENTATION ALGORITHM.
    ********************************/

    /*
    Fast algorithm is supported only when certain criteria are met:
    - VMA_DEBUG_MARGIN is 0.
    - All allocations in this block vector are moveable.
    - There is no possibility of image/buffer granularity conflict.
    */
    if(VMA_DEBUG_MARGIN == 0 &&
        allAllocations &&
        !m_pBlockVector->IsBufferImageGranularityConflictPossible())
    {
        m_pAlgorithm = vma_new(m_hAllocator, VmaDefragmentationAlgorithm_Fast)(
            m_hAllocator, m_pBlockVector, m_CurrFrameIndex, overlappingMoveSupported);
    }
    else
    {
        m_pAlgorithm = vma_new(m_hAllocator, VmaDefragmentationAlgorithm_Generic)(
            m_hAllocator, m_pBlockVector, m_CurrFrameIndex, overlappingMoveSupported);
    }

    if(allAllocations)
    {
        m_pAlgorithm->AddAll();
    }
    else
    {
        for(size_t i = 0, count = m_Allocations.size(); i < count; ++i)
        {
            m_pAlgorithm->AddAllocation(m_Allocations[i].hAlloc, m_Allocations[i].pChanged);
        }
    }
}

// VmaDefragmentationContext

VmaDefragmentationContext_T::VmaDefragmentationContext_T(
    VmaAllocator hAllocator,
    uint32_t currFrameIndex,
    uint32_t flags,
    VmaDefragmentationStats* pStats) :
    m_hAllocator(hAllocator),
    m_CurrFrameIndex(currFrameIndex),
    m_Flags(flags),
    m_pStats(pStats),
    m_CustomPoolContexts(VmaStlAllocator<VmaBlockVectorDefragmentationContext*>(hAllocator->GetAllocationCallbacks()))
{
    memset(m_DefaultPoolContexts, 0, sizeof(m_DefaultPoolContexts));
}

VmaDefragmentationContext_T::~VmaDefragmentationContext_T()
{
    for(size_t i = m_CustomPoolContexts.size(); i--; )
    {
        VmaBlockVectorDefragmentationContext* pBlockVectorCtx = m_CustomPoolContexts[i];
        pBlockVectorCtx->GetBlockVector()->DefragmentationEnd(pBlockVectorCtx, m_pStats);
        vma_delete(m_hAllocator, pBlockVectorCtx);
    }
    for(size_t i = m_hAllocator->m_MemProps.memoryTypeCount; i--; )
    {
        VmaBlockVectorDefragmentationContext* pBlockVectorCtx = m_DefaultPoolContexts[i];
        if(pBlockVectorCtx)
        {
            pBlockVectorCtx->GetBlockVector()->DefragmentationEnd(pBlockVectorCtx, m_pStats);
            vma_delete(m_hAllocator, pBlockVectorCtx);
        }
    }
}

void VmaDefragmentationContext_T::AddPools(uint32_t poolCount, VmaPool* pPools)
{
    for(uint32_t poolIndex = 0; poolIndex < poolCount; ++poolIndex)
    {
        VmaPool pool = pPools[poolIndex];
        VMA_ASSERT(pool);
        // Pools with algorithm other than default are not defragmented.
        if(pool->m_BlockVector.GetAlgorithm() == 0)
        {
            VmaBlockVectorDefragmentationContext* pBlockVectorDefragCtx = VMA_NULL;
            
            for(size_t i = m_CustomPoolContexts.size(); i--; )
            {
                if(m_CustomPoolContexts[i]->GetCustomPool() == pool)
                {
                    pBlockVectorDefragCtx = m_CustomPoolContexts[i];
                    break;
                }
            }
            
            if(!pBlockVectorDefragCtx)
            {
                pBlockVectorDefragCtx = vma_new(m_hAllocator, VmaBlockVectorDefragmentationContext)(
                    m_hAllocator,
                    pool,
                    &pool->m_BlockVector,
                    m_CurrFrameIndex,
                    m_Flags);
                m_CustomPoolContexts.push_back(pBlockVectorDefragCtx);
            }

            pBlockVectorDefragCtx->AddAll();
        }
    }
}

void VmaDefragmentationContext_T::AddAllocations(
    uint32_t allocationCount,
    VmaAllocation* pAllocations,
    VkBool32* pAllocationsChanged)
{
    // Dispatch pAllocations among defragmentators. Create them when necessary.
    for(uint32_t allocIndex = 0; allocIndex < allocationCount; ++allocIndex)
    {
        const VmaAllocation hAlloc = pAllocations[allocIndex];
        VMA_ASSERT(hAlloc);
        // DedicatedAlloc cannot be defragmented.
        if((hAlloc->GetType() == VmaAllocation_T::ALLOCATION_TYPE_BLOCK) &&
            // Lost allocation cannot be defragmented.
            (hAlloc->GetLastUseFrameIndex() != VMA_FRAME_INDEX_LOST))
        {
            VmaBlockVectorDefragmentationContext* pBlockVectorDefragCtx = VMA_NULL;

            const VmaPool hAllocPool = hAlloc->GetBlock()->GetParentPool();
            // This allocation belongs to custom pool.
            if(hAllocPool != VK_NULL_HANDLE)
            {
                // Pools with algorithm other than default are not defragmented.
                if(hAllocPool->m_BlockVector.GetAlgorithm() == 0)
                {
                    for(size_t i = m_CustomPoolContexts.size(); i--; )
                    {
                        if(m_CustomPoolContexts[i]->GetCustomPool() == hAllocPool)
                        {
                            pBlockVectorDefragCtx = m_CustomPoolContexts[i];
                            break;
                        }
                    }
                    if(!pBlockVectorDefragCtx)
                    {
                        pBlockVectorDefragCtx = vma_new(m_hAllocator, VmaBlockVectorDefragmentationContext)(
                            m_hAllocator,
                            hAllocPool,
                            &hAllocPool->m_BlockVector,
                            m_CurrFrameIndex,
                            m_Flags);
                        m_CustomPoolContexts.push_back(pBlockVectorDefragCtx);
                    }
                }
            }
            // This allocation belongs to default pool.
            else
            {
                const uint32_t memTypeIndex = hAlloc->GetMemoryTypeIndex();
                pBlockVectorDefragCtx = m_DefaultPoolContexts[memTypeIndex];
                if(!pBlockVectorDefragCtx)
                {
                    pBlockVectorDefragCtx = vma_new(m_hAllocator, VmaBlockVectorDefragmentationContext)(
                        m_hAllocator,
                        VMA_NULL, // hCustomPool
                        m_hAllocator->m_pBlockVectors[memTypeIndex],
                        m_CurrFrameIndex,
                        m_Flags);
                    m_DefaultPoolContexts[memTypeIndex] = pBlockVectorDefragCtx;
                }
            }

            if(pBlockVectorDefragCtx)
            {
                VkBool32* const pChanged = (pAllocationsChanged != VMA_NULL) ?
                    &pAllocationsChanged[allocIndex] : VMA_NULL;
                pBlockVectorDefragCtx->AddAllocation(hAlloc, pChanged);
            }
        }
    }
}

VkResult VmaDefragmentationContext_T::Defragment(
    VkDeviceSize maxCpuBytesToMove, uint32_t maxCpuAllocationsToMove,
    VkDeviceSize maxGpuBytesToMove, uint32_t maxGpuAllocationsToMove,
    VkCommandBuffer commandBuffer, VmaDefragmentationStats* pStats)
{
    if(pStats)
    {
        memset(pStats, 0, sizeof(VmaDefragmentationStats));
    }

    if(commandBuffer == VK_NULL_HANDLE)
    {
        maxGpuBytesToMove = 0;
        maxGpuAllocationsToMove = 0;
    }

    VkResult res = VK_SUCCESS;

    // Process default pools.
    for(uint32_t memTypeIndex = 0;
        memTypeIndex < m_hAllocator->GetMemoryTypeCount() && res >= VK_SUCCESS;
        ++memTypeIndex)
    {
        VmaBlockVectorDefragmentationContext* pBlockVectorCtx = m_DefaultPoolContexts[memTypeIndex];
        if(pBlockVectorCtx)
        {
            VMA_ASSERT(pBlockVectorCtx->GetBlockVector());
            pBlockVectorCtx->GetBlockVector()->Defragment(
                pBlockVectorCtx,
                pStats,
                maxCpuBytesToMove, maxCpuAllocationsToMove,
                maxGpuBytesToMove, maxGpuAllocationsToMove,
                commandBuffer);
            if(pBlockVectorCtx->res != VK_SUCCESS)
            {
                res = pBlockVectorCtx->res;
            }
        }
    }

    // Process custom pools.
    for(size_t customCtxIndex = 0, customCtxCount = m_CustomPoolContexts.size();
        customCtxIndex < customCtxCount && res >= VK_SUCCESS;
        ++customCtxIndex)
    {
        VmaBlockVectorDefragmentationContext* pBlockVectorCtx = m_CustomPoolContexts[customCtxIndex];
        VMA_ASSERT(pBlockVectorCtx && pBlockVectorCtx->GetBlockVector());
        pBlockVectorCtx->GetBlockVector()->Defragment(
            pBlockVectorCtx,
            pStats,
            maxCpuBytesToMove, maxCpuAllocationsToMove,
            maxGpuBytesToMove, maxGpuAllocationsToMove,
            commandBuffer);
        if(pBlockVectorCtx->res != VK_SUCCESS)
        {
            res = pBlockVectorCtx->res;
        }
    }

    return res;
}

// VmaRecorder

#if VMA_RECORDING_ENABLED

VmaRecorder::VmaRecorder() :
    m_UseMutex(true),
    m_Flags(0),
    m_File(VMA_NULL),
    m_Freq(INT64_MAX),
    m_StartCounter(INT64_MAX)
{
}

VkResult VmaRecorder::Init(const VmaRecordSettings& settings, bool useMutex)
{
    m_UseMutex = useMutex;
    m_Flags = settings.flags;

    QueryPerformanceFrequency((LARGE_INTEGER*)&m_Freq);
    QueryPerformanceCounter((LARGE_INTEGER*)&m_StartCounter);

    // Open file for writing.
    errno_t err = fopen_s(&m_File, settings.pFilePath, "wb");
    if(err != 0)
    {
        return VK_ERROR_INITIALIZATION_FAILED;
    }

    // Write header.
    fprintf(m_File, "%s\n", "Vulkan Memory Allocator,Calls recording");
    fprintf(m_File, "%s\n", "1,5");

    return VK_SUCCESS;
}

VmaRecorder::~VmaRecorder()
{
    if(m_File != VMA_NULL)
    {
        fclose(m_File);
    }
}

void VmaRecorder::RecordCreateAllocator(uint32_t frameIndex)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaCreateAllocator\n", callParams.threadId, callParams.time, frameIndex);
    Flush();
}

void VmaRecorder::RecordDestroyAllocator(uint32_t frameIndex)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaDestroyAllocator\n", callParams.threadId, callParams.time, frameIndex);
    Flush();
}

void VmaRecorder::RecordCreatePool(uint32_t frameIndex, const VmaPoolCreateInfo& createInfo, VmaPool pool)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaCreatePool,%u,%u,%llu,%llu,%llu,%u,%p\n", callParams.threadId, callParams.time, frameIndex,
        createInfo.memoryTypeIndex,
        createInfo.flags,
        createInfo.blockSize,
        (uint64_t)createInfo.minBlockCount,
        (uint64_t)createInfo.maxBlockCount,
        createInfo.frameInUseCount,
        pool);
    Flush();
}

void VmaRecorder::RecordDestroyPool(uint32_t frameIndex, VmaPool pool)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaDestroyPool,%p\n", callParams.threadId, callParams.time, frameIndex,
        pool);
    Flush();
}

void VmaRecorder::RecordAllocateMemory(uint32_t frameIndex,
        const VkMemoryRequirements& vkMemReq,
        const VmaAllocationCreateInfo& createInfo,
        VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    UserDataString userDataStr(createInfo.flags, createInfo.pUserData);
    fprintf(m_File, "%u,%.3f,%u,vmaAllocateMemory,%llu,%llu,%u,%u,%u,%u,%u,%u,%p,%p,%s\n", callParams.threadId, callParams.time, frameIndex,
        vkMemReq.size,
        vkMemReq.alignment,
        vkMemReq.memoryTypeBits,
        createInfo.flags,
        createInfo.usage,
        createInfo.requiredFlags,
        createInfo.preferredFlags,
        createInfo.memoryTypeBits,
        createInfo.pool,
        allocation,
        userDataStr.GetString());
    Flush();
}

void VmaRecorder::RecordAllocateMemoryPages(uint32_t frameIndex,
    const VkMemoryRequirements& vkMemReq,
    const VmaAllocationCreateInfo& createInfo,
    uint64_t allocationCount,
    const VmaAllocation* pAllocations)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    UserDataString userDataStr(createInfo.flags, createInfo.pUserData);
    fprintf(m_File, "%u,%.3f,%u,vmaAllocateMemoryPages,%llu,%llu,%u,%u,%u,%u,%u,%u,%p,", callParams.threadId, callParams.time, frameIndex,
        vkMemReq.size,
        vkMemReq.alignment,
        vkMemReq.memoryTypeBits,
        createInfo.flags,
        createInfo.usage,
        createInfo.requiredFlags,
        createInfo.preferredFlags,
        createInfo.memoryTypeBits,
        createInfo.pool);
    PrintPointerList(allocationCount, pAllocations);
    fprintf(m_File, ",%s\n", userDataStr.GetString());
    Flush();
}

void VmaRecorder::RecordAllocateMemoryForBuffer(uint32_t frameIndex,
    const VkMemoryRequirements& vkMemReq,
    bool requiresDedicatedAllocation,
    bool prefersDedicatedAllocation,
    const VmaAllocationCreateInfo& createInfo,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    UserDataString userDataStr(createInfo.flags, createInfo.pUserData);
    fprintf(m_File, "%u,%.3f,%u,vmaAllocateMemoryForBuffer,%llu,%llu,%u,%u,%u,%u,%u,%u,%u,%u,%p,%p,%s\n", callParams.threadId, callParams.time, frameIndex,
        vkMemReq.size,
        vkMemReq.alignment,
        vkMemReq.memoryTypeBits,
        requiresDedicatedAllocation ? 1 : 0,
        prefersDedicatedAllocation ? 1 : 0,
        createInfo.flags,
        createInfo.usage,
        createInfo.requiredFlags,
        createInfo.preferredFlags,
        createInfo.memoryTypeBits,
        createInfo.pool,
        allocation,
        userDataStr.GetString());
    Flush();
}

void VmaRecorder::RecordAllocateMemoryForImage(uint32_t frameIndex,
    const VkMemoryRequirements& vkMemReq,
    bool requiresDedicatedAllocation,
    bool prefersDedicatedAllocation,
    const VmaAllocationCreateInfo& createInfo,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    UserDataString userDataStr(createInfo.flags, createInfo.pUserData);
    fprintf(m_File, "%u,%.3f,%u,vmaAllocateMemoryForImage,%llu,%llu,%u,%u,%u,%u,%u,%u,%u,%u,%p,%p,%s\n", callParams.threadId, callParams.time, frameIndex,
        vkMemReq.size,
        vkMemReq.alignment,
        vkMemReq.memoryTypeBits,
        requiresDedicatedAllocation ? 1 : 0,
        prefersDedicatedAllocation ? 1 : 0,
        createInfo.flags,
        createInfo.usage,
        createInfo.requiredFlags,
        createInfo.preferredFlags,
        createInfo.memoryTypeBits,
        createInfo.pool,
        allocation,
        userDataStr.GetString());
    Flush();
}

void VmaRecorder::RecordFreeMemory(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaFreeMemory,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordFreeMemoryPages(uint32_t frameIndex,
    uint64_t allocationCount,
    const VmaAllocation* pAllocations)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaFreeMemoryPages,", callParams.threadId, callParams.time, frameIndex);
    PrintPointerList(allocationCount, pAllocations);
    fprintf(m_File, "\n");
    Flush();
}

void VmaRecorder::RecordResizeAllocation(
    uint32_t frameIndex,
    VmaAllocation allocation,
    VkDeviceSize newSize)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaResizeAllocation,%p,%llu\n", callParams.threadId, callParams.time, frameIndex,
        allocation, newSize);
    Flush();
}

void VmaRecorder::RecordSetAllocationUserData(uint32_t frameIndex,
    VmaAllocation allocation,
    const void* pUserData)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    UserDataString userDataStr(
        allocation->IsUserDataString() ? VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT : 0,
        pUserData);
    fprintf(m_File, "%u,%.3f,%u,vmaSetAllocationUserData,%p,%s\n", callParams.threadId, callParams.time, frameIndex,
        allocation,
        userDataStr.GetString());
    Flush();
}

void VmaRecorder::RecordCreateLostAllocation(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaCreateLostAllocation,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordMapMemory(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaMapMemory,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordUnmapMemory(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaUnmapMemory,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordFlushAllocation(uint32_t frameIndex,
    VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaFlushAllocation,%p,%llu,%llu\n", callParams.threadId, callParams.time, frameIndex,
        allocation,
        offset,
        size);
    Flush();
}

void VmaRecorder::RecordInvalidateAllocation(uint32_t frameIndex,
    VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaInvalidateAllocation,%p,%llu,%llu\n", callParams.threadId, callParams.time, frameIndex,
        allocation,
        offset,
        size);
    Flush();
}

void VmaRecorder::RecordCreateBuffer(uint32_t frameIndex,
    const VkBufferCreateInfo& bufCreateInfo,
    const VmaAllocationCreateInfo& allocCreateInfo,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    UserDataString userDataStr(allocCreateInfo.flags, allocCreateInfo.pUserData);
    fprintf(m_File, "%u,%.3f,%u,vmaCreateBuffer,%u,%llu,%u,%u,%u,%u,%u,%u,%u,%p,%p,%s\n", callParams.threadId, callParams.time, frameIndex,
        bufCreateInfo.flags,
        bufCreateInfo.size,
        bufCreateInfo.usage,
        bufCreateInfo.sharingMode,
        allocCreateInfo.flags,
        allocCreateInfo.usage,
        allocCreateInfo.requiredFlags,
        allocCreateInfo.preferredFlags,
        allocCreateInfo.memoryTypeBits,
        allocCreateInfo.pool,
        allocation,
        userDataStr.GetString());
    Flush();
}

void VmaRecorder::RecordCreateImage(uint32_t frameIndex,
    const VkImageCreateInfo& imageCreateInfo,
    const VmaAllocationCreateInfo& allocCreateInfo,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    UserDataString userDataStr(allocCreateInfo.flags, allocCreateInfo.pUserData);
    fprintf(m_File, "%u,%.3f,%u,vmaCreateImage,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%p,%p,%s\n", callParams.threadId, callParams.time, frameIndex,
        imageCreateInfo.flags,
        imageCreateInfo.imageType,
        imageCreateInfo.format,
        imageCreateInfo.extent.width,
        imageCreateInfo.extent.height,
        imageCreateInfo.extent.depth,
        imageCreateInfo.mipLevels,
        imageCreateInfo.arrayLayers,
        imageCreateInfo.samples,
        imageCreateInfo.tiling,
        imageCreateInfo.usage,
        imageCreateInfo.sharingMode,
        imageCreateInfo.initialLayout,
        allocCreateInfo.flags,
        allocCreateInfo.usage,
        allocCreateInfo.requiredFlags,
        allocCreateInfo.preferredFlags,
        allocCreateInfo.memoryTypeBits,
        allocCreateInfo.pool,
        allocation,
        userDataStr.GetString());
    Flush();
}

void VmaRecorder::RecordDestroyBuffer(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaDestroyBuffer,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordDestroyImage(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaDestroyImage,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordTouchAllocation(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaTouchAllocation,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordGetAllocationInfo(uint32_t frameIndex,
    VmaAllocation allocation)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaGetAllocationInfo,%p\n", callParams.threadId, callParams.time, frameIndex,
        allocation);
    Flush();
}

void VmaRecorder::RecordMakePoolAllocationsLost(uint32_t frameIndex,
    VmaPool pool)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaMakePoolAllocationsLost,%p\n", callParams.threadId, callParams.time, frameIndex,
        pool);
    Flush();
}

void VmaRecorder::RecordDefragmentationBegin(uint32_t frameIndex,
    const VmaDefragmentationInfo2& info,
    VmaDefragmentationContext ctx)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaDefragmentationBegin,%u,", callParams.threadId, callParams.time, frameIndex,
        info.flags);
    PrintPointerList(info.allocationCount, info.pAllocations);
    fprintf(m_File, ",");
    PrintPointerList(info.poolCount, info.pPools);
    fprintf(m_File, ",%llu,%u,%llu,%u,%p,%p\n",
        info.maxCpuBytesToMove,
        info.maxCpuAllocationsToMove,
        info.maxGpuBytesToMove,
        info.maxGpuAllocationsToMove,
        info.commandBuffer,
        ctx);
    Flush();
}

void VmaRecorder::RecordDefragmentationEnd(uint32_t frameIndex,
    VmaDefragmentationContext ctx)
{
    CallParams callParams;
    GetBasicParams(callParams);

    VmaMutexLock lock(m_FileMutex, m_UseMutex);
    fprintf(m_File, "%u,%.3f,%u,vmaDefragmentationEnd,%p\n", callParams.threadId, callParams.time, frameIndex,
        ctx);
    Flush();
}

VmaRecorder::UserDataString::UserDataString(VmaAllocationCreateFlags allocFlags, const void* pUserData)
{
    if(pUserData != VMA_NULL)
    {
        if((allocFlags & VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT) != 0)
        {
            m_Str = (const char*)pUserData;
        }
        else
        {
            sprintf_s(m_PtrStr, "%p", pUserData);
            m_Str = m_PtrStr;
        }
    }
    else
    {
        m_Str = "";
    }
}

void VmaRecorder::WriteConfiguration(
    const VkPhysicalDeviceProperties& devProps,
    const VkPhysicalDeviceMemoryProperties& memProps,
    bool dedicatedAllocationExtensionEnabled)
{
    fprintf(m_File, "Config,Begin\n");

    fprintf(m_File, "PhysicalDevice,apiVersion,%u\n", devProps.apiVersion);
    fprintf(m_File, "PhysicalDevice,driverVersion,%u\n", devProps.driverVersion);
    fprintf(m_File, "PhysicalDevice,vendorID,%u\n", devProps.vendorID);
    fprintf(m_File, "PhysicalDevice,deviceID,%u\n", devProps.deviceID);
    fprintf(m_File, "PhysicalDevice,deviceType,%u\n", devProps.deviceType);
    fprintf(m_File, "PhysicalDevice,deviceName,%s\n", devProps.deviceName);

    fprintf(m_File, "PhysicalDeviceLimits,maxMemoryAllocationCount,%u\n", devProps.limits.maxMemoryAllocationCount);
    fprintf(m_File, "PhysicalDeviceLimits,bufferImageGranularity,%llu\n", devProps.limits.bufferImageGranularity);
    fprintf(m_File, "PhysicalDeviceLimits,nonCoherentAtomSize,%llu\n", devProps.limits.nonCoherentAtomSize);

    fprintf(m_File, "PhysicalDeviceMemory,HeapCount,%u\n", memProps.memoryHeapCount);
    for(uint32_t i = 0; i < memProps.memoryHeapCount; ++i)
    {
        fprintf(m_File, "PhysicalDeviceMemory,Heap,%u,size,%llu\n", i, memProps.memoryHeaps[i].size);
        fprintf(m_File, "PhysicalDeviceMemory,Heap,%u,flags,%u\n", i, memProps.memoryHeaps[i].flags);
    }
    fprintf(m_File, "PhysicalDeviceMemory,TypeCount,%u\n", memProps.memoryTypeCount);
    for(uint32_t i = 0; i < memProps.memoryTypeCount; ++i)
    {
        fprintf(m_File, "PhysicalDeviceMemory,Type,%u,heapIndex,%u\n", i, memProps.memoryTypes[i].heapIndex);
        fprintf(m_File, "PhysicalDeviceMemory,Type,%u,propertyFlags,%u\n", i, memProps.memoryTypes[i].propertyFlags);
    }

    fprintf(m_File, "Extension,VK_KHR_dedicated_allocation,%u\n", dedicatedAllocationExtensionEnabled ? 1 : 0);

    fprintf(m_File, "Macro,VMA_DEBUG_ALWAYS_DEDICATED_MEMORY,%u\n", VMA_DEBUG_ALWAYS_DEDICATED_MEMORY ? 1 : 0);
    fprintf(m_File, "Macro,VMA_DEBUG_ALIGNMENT,%llu\n", (VkDeviceSize)VMA_DEBUG_ALIGNMENT);
    fprintf(m_File, "Macro,VMA_DEBUG_MARGIN,%llu\n", (VkDeviceSize)VMA_DEBUG_MARGIN);
    fprintf(m_File, "Macro,VMA_DEBUG_INITIALIZE_ALLOCATIONS,%u\n", VMA_DEBUG_INITIALIZE_ALLOCATIONS ? 1 : 0);
    fprintf(m_File, "Macro,VMA_DEBUG_DETECT_CORRUPTION,%u\n", VMA_DEBUG_DETECT_CORRUPTION ? 1 : 0);
    fprintf(m_File, "Macro,VMA_DEBUG_GLOBAL_MUTEX,%u\n", VMA_DEBUG_GLOBAL_MUTEX ? 1 : 0);
    fprintf(m_File, "Macro,VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY,%llu\n", (VkDeviceSize)VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY);
    fprintf(m_File, "Macro,VMA_SMALL_HEAP_MAX_SIZE,%llu\n", (VkDeviceSize)VMA_SMALL_HEAP_MAX_SIZE);
    fprintf(m_File, "Macro,VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE,%llu\n", (VkDeviceSize)VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE);

    fprintf(m_File, "Config,End\n");
}

void VmaRecorder::GetBasicParams(CallParams& outParams)
{
    outParams.threadId = GetCurrentThreadId();

    LARGE_INTEGER counter;
    QueryPerformanceCounter(&counter);
    outParams.time = (double)(counter.QuadPart - m_StartCounter) / (double)m_Freq;
}

void VmaRecorder::PrintPointerList(uint64_t count, const VmaAllocation* pItems)
{
    if(count)
    {
        fprintf(m_File, "%p", pItems[0]);
        for(uint64_t i = 1; i < count; ++i)
        {
            fprintf(m_File, " %p", pItems[i]);
        }
    }
}

void VmaRecorder::Flush()
{
    if((m_Flags & VMA_RECORD_FLUSH_AFTER_CALL_BIT) != 0)
    {
        fflush(m_File);
    }
}

#endif // #if VMA_RECORDING_ENABLED

// VmaAllocationObjectAllocator

VmaAllocationObjectAllocator::VmaAllocationObjectAllocator(const VkAllocationCallbacks* pAllocationCallbacks) :
    m_Allocator(pAllocationCallbacks, 1024)
{
}

VmaAllocation VmaAllocationObjectAllocator::Allocate()
{
    VmaMutexLock mutexLock(m_Mutex);
    return m_Allocator.Alloc();
}

void VmaAllocationObjectAllocator::Free(VmaAllocation hAlloc)
{
    VmaMutexLock mutexLock(m_Mutex);
    m_Allocator.Free(hAlloc);
}

// VmaAllocator_T

VmaAllocator_T::VmaAllocator_T(const VmaAllocatorCreateInfo* pCreateInfo) :
    m_UseMutex((pCreateInfo->flags & VMA_ALLOCATOR_CREATE_EXTERNALLY_SYNCHRONIZED_BIT) == 0),
    m_UseKhrDedicatedAllocation((pCreateInfo->flags & VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT) != 0),
    m_hDevice(pCreateInfo->device),
    m_AllocationCallbacksSpecified(pCreateInfo->pAllocationCallbacks != VMA_NULL),
    m_AllocationCallbacks(pCreateInfo->pAllocationCallbacks ?
        *pCreateInfo->pAllocationCallbacks : VmaEmptyAllocationCallbacks),
    m_AllocationObjectAllocator(&m_AllocationCallbacks),
    m_PreferredLargeHeapBlockSize(0),
    m_PhysicalDevice(pCreateInfo->physicalDevice),
    m_CurrentFrameIndex(0),
    m_GpuDefragmentationMemoryTypeBits(UINT32_MAX),
    m_Pools(VmaStlAllocator<VmaPool>(GetAllocationCallbacks())),
    m_NextPoolId(0)
#if VMA_RECORDING_ENABLED
    ,m_pRecorder(VMA_NULL)
#endif
{
    if(VMA_DEBUG_DETECT_CORRUPTION)
    {
        // Needs to be multiply of uint32_t size because we are going to write VMA_CORRUPTION_DETECTION_MAGIC_VALUE to it.
        VMA_ASSERT(VMA_DEBUG_MARGIN % sizeof(uint32_t) == 0);
    }

    VMA_ASSERT(pCreateInfo->physicalDevice && pCreateInfo->device);

#if !(VMA_DEDICATED_ALLOCATION)
    if((pCreateInfo->flags & VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT) != 0)
    {
        VMA_ASSERT(0 && "VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT set but required extensions are disabled by preprocessor macros.");
    }
#endif

    memset(&m_DeviceMemoryCallbacks, 0 ,sizeof(m_DeviceMemoryCallbacks));
    memset(&m_PhysicalDeviceProperties, 0, sizeof(m_PhysicalDeviceProperties));
    memset(&m_MemProps, 0, sizeof(m_MemProps));
        
    memset(&m_pBlockVectors, 0, sizeof(m_pBlockVectors));
    memset(&m_pDedicatedAllocations, 0, sizeof(m_pDedicatedAllocations));

    for(uint32_t i = 0; i < VK_MAX_MEMORY_HEAPS; ++i)
    {
        m_HeapSizeLimit[i] = VK_WHOLE_SIZE;
    }

    if(pCreateInfo->pDeviceMemoryCallbacks != VMA_NULL)
    {
        m_DeviceMemoryCallbacks.pfnAllocate = pCreateInfo->pDeviceMemoryCallbacks->pfnAllocate;
        m_DeviceMemoryCallbacks.pfnFree = pCreateInfo->pDeviceMemoryCallbacks->pfnFree;
    }

    ImportVulkanFunctions(pCreateInfo->pVulkanFunctions);

    (*m_VulkanFunctions.vkGetPhysicalDeviceProperties)(m_PhysicalDevice, &m_PhysicalDeviceProperties);
    (*m_VulkanFunctions.vkGetPhysicalDeviceMemoryProperties)(m_PhysicalDevice, &m_MemProps);

    VMA_ASSERT(VmaIsPow2(VMA_DEBUG_ALIGNMENT));
    VMA_ASSERT(VmaIsPow2(VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY));
    VMA_ASSERT(VmaIsPow2(m_PhysicalDeviceProperties.limits.bufferImageGranularity));
    VMA_ASSERT(VmaIsPow2(m_PhysicalDeviceProperties.limits.nonCoherentAtomSize));

    m_PreferredLargeHeapBlockSize = (pCreateInfo->preferredLargeHeapBlockSize != 0) ?
        pCreateInfo->preferredLargeHeapBlockSize : static_cast<VkDeviceSize>(VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE);

    if(pCreateInfo->pHeapSizeLimit != VMA_NULL)
    {
        for(uint32_t heapIndex = 0; heapIndex < GetMemoryHeapCount(); ++heapIndex)
        {
            const VkDeviceSize limit = pCreateInfo->pHeapSizeLimit[heapIndex];
            if(limit != VK_WHOLE_SIZE)
            {
                m_HeapSizeLimit[heapIndex] = limit;
                if(limit < m_MemProps.memoryHeaps[heapIndex].size)
                {
                    m_MemProps.memoryHeaps[heapIndex].size = limit;
                }
            }
        }
    }

    for(uint32_t memTypeIndex = 0; memTypeIndex < GetMemoryTypeCount(); ++memTypeIndex)
    {
        const VkDeviceSize preferredBlockSize = CalcPreferredBlockSize(memTypeIndex);

        m_pBlockVectors[memTypeIndex] = vma_new(this, VmaBlockVector)(
            this,
            VK_NULL_HANDLE, // hParentPool
            memTypeIndex,
            preferredBlockSize,
            0,
            SIZE_MAX,
            GetBufferImageGranularity(),
            pCreateInfo->frameInUseCount,
            false, // isCustomPool
            false, // explicitBlockSize
            false); // linearAlgorithm
        // No need to call m_pBlockVectors[memTypeIndex][blockVectorTypeIndex]->CreateMinBlocks here,
        // becase minBlockCount is 0.
        m_pDedicatedAllocations[memTypeIndex] = vma_new(this, AllocationVectorType)(VmaStlAllocator<VmaAllocation>(GetAllocationCallbacks()));

    }
}

VkResult VmaAllocator_T::Init(const VmaAllocatorCreateInfo* pCreateInfo)
{
    VkResult res = VK_SUCCESS;

    if(pCreateInfo->pRecordSettings != VMA_NULL &&
        !VmaStrIsEmpty(pCreateInfo->pRecordSettings->pFilePath))
    {
#if VMA_RECORDING_ENABLED
        m_pRecorder = vma_new(this, VmaRecorder)();
        res = m_pRecorder->Init(*pCreateInfo->pRecordSettings, m_UseMutex);
        if(res != VK_SUCCESS)
        {
            return res;
        }
        m_pRecorder->WriteConfiguration(
            m_PhysicalDeviceProperties,
            m_MemProps,
            m_UseKhrDedicatedAllocation);
        m_pRecorder->RecordCreateAllocator(GetCurrentFrameIndex());
#else
        VMA_ASSERT(0 && "VmaAllocatorCreateInfo::pRecordSettings used, but not supported due to VMA_RECORDING_ENABLED not defined to 1.");
        return VK_ERROR_FEATURE_NOT_PRESENT;
#endif
    }

    return res;
}

VmaAllocator_T::~VmaAllocator_T()
{
#if VMA_RECORDING_ENABLED
    if(m_pRecorder != VMA_NULL)
    {
        m_pRecorder->RecordDestroyAllocator(GetCurrentFrameIndex());
        vma_delete(this, m_pRecorder);
    }
#endif
    
    VMA_ASSERT(m_Pools.empty());

    for(size_t i = GetMemoryTypeCount(); i--; )
    {
        if(m_pDedicatedAllocations[i] != VMA_NULL && !m_pDedicatedAllocations[i]->empty())
        {
            VMA_ASSERT(0 && "Unfreed dedicated allocations found.");
        }

        vma_delete(this, m_pDedicatedAllocations[i]);
        vma_delete(this, m_pBlockVectors[i]);
    }
}

void VmaAllocator_T::ImportVulkanFunctions(const VmaVulkanFunctions* pVulkanFunctions)
{
#if VMA_STATIC_VULKAN_FUNCTIONS == 1
    m_VulkanFunctions.vkGetPhysicalDeviceProperties = (PFN_vkGetPhysicalDeviceProperties)vkGetPhysicalDeviceProperties;
    m_VulkanFunctions.vkGetPhysicalDeviceMemoryProperties = (PFN_vkGetPhysicalDeviceMemoryProperties)vkGetPhysicalDeviceMemoryProperties;
    m_VulkanFunctions.vkAllocateMemory = (PFN_vkAllocateMemory)vkAllocateMemory;
    m_VulkanFunctions.vkFreeMemory = (PFN_vkFreeMemory)vkFreeMemory;
    m_VulkanFunctions.vkMapMemory = (PFN_vkMapMemory)vkMapMemory;
    m_VulkanFunctions.vkUnmapMemory = (PFN_vkUnmapMemory)vkUnmapMemory;
    m_VulkanFunctions.vkFlushMappedMemoryRanges = (PFN_vkFlushMappedMemoryRanges)vkFlushMappedMemoryRanges;
    m_VulkanFunctions.vkInvalidateMappedMemoryRanges = (PFN_vkInvalidateMappedMemoryRanges)vkInvalidateMappedMemoryRanges;
    m_VulkanFunctions.vkBindBufferMemory = (PFN_vkBindBufferMemory)vkBindBufferMemory;
    m_VulkanFunctions.vkBindImageMemory = (PFN_vkBindImageMemory)vkBindImageMemory;
    m_VulkanFunctions.vkGetBufferMemoryRequirements = (PFN_vkGetBufferMemoryRequirements)vkGetBufferMemoryRequirements;
    m_VulkanFunctions.vkGetImageMemoryRequirements = (PFN_vkGetImageMemoryRequirements)vkGetImageMemoryRequirements;
    m_VulkanFunctions.vkCreateBuffer = (PFN_vkCreateBuffer)vkCreateBuffer;
    m_VulkanFunctions.vkDestroyBuffer = (PFN_vkDestroyBuffer)vkDestroyBuffer;
    m_VulkanFunctions.vkCreateImage = (PFN_vkCreateImage)vkCreateImage;
    m_VulkanFunctions.vkDestroyImage = (PFN_vkDestroyImage)vkDestroyImage;
    m_VulkanFunctions.vkCmdCopyBuffer = (PFN_vkCmdCopyBuffer)vkCmdCopyBuffer;
#if VMA_DEDICATED_ALLOCATION
    if(m_UseKhrDedicatedAllocation)
    {
        m_VulkanFunctions.vkGetBufferMemoryRequirements2KHR =
            (PFN_vkGetBufferMemoryRequirements2KHR)vkGetDeviceProcAddr(m_hDevice, "vkGetBufferMemoryRequirements2KHR");
        m_VulkanFunctions.vkGetImageMemoryRequirements2KHR =
            (PFN_vkGetImageMemoryRequirements2KHR)vkGetDeviceProcAddr(m_hDevice, "vkGetImageMemoryRequirements2KHR");
    }
#endif // #if VMA_DEDICATED_ALLOCATION
#endif // #if VMA_STATIC_VULKAN_FUNCTIONS == 1

#define VMA_COPY_IF_NOT_NULL(funcName) \
    if(pVulkanFunctions->funcName != VMA_NULL) m_VulkanFunctions.funcName = pVulkanFunctions->funcName;

    if(pVulkanFunctions != VMA_NULL)
    {
        VMA_COPY_IF_NOT_NULL(vkGetPhysicalDeviceProperties);
        VMA_COPY_IF_NOT_NULL(vkGetPhysicalDeviceMemoryProperties);
        VMA_COPY_IF_NOT_NULL(vkAllocateMemory);
        VMA_COPY_IF_NOT_NULL(vkFreeMemory);
        VMA_COPY_IF_NOT_NULL(vkMapMemory);
        VMA_COPY_IF_NOT_NULL(vkUnmapMemory);
        VMA_COPY_IF_NOT_NULL(vkFlushMappedMemoryRanges);
        VMA_COPY_IF_NOT_NULL(vkInvalidateMappedMemoryRanges);
        VMA_COPY_IF_NOT_NULL(vkBindBufferMemory);
        VMA_COPY_IF_NOT_NULL(vkBindImageMemory);
        VMA_COPY_IF_NOT_NULL(vkGetBufferMemoryRequirements);
        VMA_COPY_IF_NOT_NULL(vkGetImageMemoryRequirements);
        VMA_COPY_IF_NOT_NULL(vkCreateBuffer);
        VMA_COPY_IF_NOT_NULL(vkDestroyBuffer);
        VMA_COPY_IF_NOT_NULL(vkCreateImage);
        VMA_COPY_IF_NOT_NULL(vkDestroyImage);
        VMA_COPY_IF_NOT_NULL(vkCmdCopyBuffer);
#if VMA_DEDICATED_ALLOCATION
        VMA_COPY_IF_NOT_NULL(vkGetBufferMemoryRequirements2KHR);
        VMA_COPY_IF_NOT_NULL(vkGetImageMemoryRequirements2KHR);
#endif
    }

#undef VMA_COPY_IF_NOT_NULL

    // If these asserts are hit, you must either #define VMA_STATIC_VULKAN_FUNCTIONS 1
    // or pass valid pointers as VmaAllocatorCreateInfo::pVulkanFunctions.
    VMA_ASSERT(m_VulkanFunctions.vkGetPhysicalDeviceProperties != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkGetPhysicalDeviceMemoryProperties != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkAllocateMemory != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkFreeMemory != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkMapMemory != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkUnmapMemory != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkFlushMappedMemoryRanges != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkInvalidateMappedMemoryRanges != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkBindBufferMemory != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkBindImageMemory != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkGetBufferMemoryRequirements != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkGetImageMemoryRequirements != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkCreateBuffer != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkDestroyBuffer != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkCreateImage != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkDestroyImage != VMA_NULL);
    VMA_ASSERT(m_VulkanFunctions.vkCmdCopyBuffer != VMA_NULL);
#if VMA_DEDICATED_ALLOCATION
    if(m_UseKhrDedicatedAllocation)
    {
        VMA_ASSERT(m_VulkanFunctions.vkGetBufferMemoryRequirements2KHR != VMA_NULL);
        VMA_ASSERT(m_VulkanFunctions.vkGetImageMemoryRequirements2KHR != VMA_NULL);
    }
#endif
}

VkDeviceSize VmaAllocator_T::CalcPreferredBlockSize(uint32_t memTypeIndex)
{
    const uint32_t heapIndex = MemoryTypeIndexToHeapIndex(memTypeIndex);
    const VkDeviceSize heapSize = m_MemProps.memoryHeaps[heapIndex].size;
    const bool isSmallHeap = heapSize <= VMA_SMALL_HEAP_MAX_SIZE;
    return isSmallHeap ? (heapSize / 8) : m_PreferredLargeHeapBlockSize;
}

VkResult VmaAllocator_T::AllocateMemoryOfType(
    VkDeviceSize size,
    VkDeviceSize alignment,
    bool dedicatedAllocation,
    VkBuffer dedicatedBuffer,
    VkImage dedicatedImage,
    const VmaAllocationCreateInfo& createInfo,
    uint32_t memTypeIndex,
    VmaSuballocationType suballocType,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{
    VMA_ASSERT(pAllocations != VMA_NULL);
    VMA_DEBUG_LOG("  AllocateMemory: MemoryTypeIndex=%u, AllocationCount=%zu, Size=%llu", memTypeIndex, allocationCount, size);

    VmaAllocationCreateInfo finalCreateInfo = createInfo;

    // If memory type is not HOST_VISIBLE, disable MAPPED.
    if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_MAPPED_BIT) != 0 &&
        (m_MemProps.memoryTypes[memTypeIndex].propertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) == 0)
    {
        finalCreateInfo.flags &= ~VMA_ALLOCATION_CREATE_MAPPED_BIT;
    }

    VmaBlockVector* const blockVector = m_pBlockVectors[memTypeIndex];
    VMA_ASSERT(blockVector);

    const VkDeviceSize preferredBlockSize = blockVector->GetPreferredBlockSize();
    bool preferDedicatedMemory =
        VMA_DEBUG_ALWAYS_DEDICATED_MEMORY ||
        dedicatedAllocation ||
        // Heuristics: Allocate dedicated memory if requested size if greater than half of preferred block size.
        size > preferredBlockSize / 2;

    if(preferDedicatedMemory &&
        (finalCreateInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) == 0 &&
        finalCreateInfo.pool == VK_NULL_HANDLE)
    {
        finalCreateInfo.flags |= VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT;
    }

    if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT) != 0)
    {
        if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) != 0)
        {
            return VK_ERROR_OUT_OF_DEVICE_MEMORY;
        }
        else
        {
            return AllocateDedicatedMemory(
                size,
                suballocType,
                memTypeIndex,
                (finalCreateInfo.flags & VMA_ALLOCATION_CREATE_MAPPED_BIT) != 0,
                (finalCreateInfo.flags & VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT) != 0,
                finalCreateInfo.pUserData,
                dedicatedBuffer,
                dedicatedImage,
                allocationCount,
                pAllocations);
        }
    }
    else
    {
        VkResult res = blockVector->Allocate(
            m_CurrentFrameIndex.load(),
            size,
            alignment,
            finalCreateInfo,
            suballocType,
            allocationCount,
            pAllocations);
        if(res == VK_SUCCESS)
        {
            return res;
        }

        // 5. Try dedicated memory.
        if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) != 0)
        {
            return VK_ERROR_OUT_OF_DEVICE_MEMORY;
        }
        else
        {
            res = AllocateDedicatedMemory(
                size,
                suballocType,
                memTypeIndex,
                (finalCreateInfo.flags & VMA_ALLOCATION_CREATE_MAPPED_BIT) != 0,
                (finalCreateInfo.flags & VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT) != 0,
                finalCreateInfo.pUserData,
                dedicatedBuffer,
                dedicatedImage,
                allocationCount,
                pAllocations);
            if(res == VK_SUCCESS)
            {
                // Succeeded: AllocateDedicatedMemory function already filld pMemory, nothing more to do here.
                VMA_DEBUG_LOG("    Allocated as DedicatedMemory");
                return VK_SUCCESS;
            }
            else
            {
                // Everything failed: Return error code.
                VMA_DEBUG_LOG("    vkAllocateMemory FAILED");
                return res;
            }
        }
    }
}

VkResult VmaAllocator_T::AllocateDedicatedMemory(
    VkDeviceSize size,
    VmaSuballocationType suballocType,
    uint32_t memTypeIndex,
    bool map,
    bool isUserDataString,
    void* pUserData,
    VkBuffer dedicatedBuffer,
    VkImage dedicatedImage,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{
    VMA_ASSERT(allocationCount > 0 && pAllocations);

    VkMemoryAllocateInfo allocInfo = { VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO };
    allocInfo.memoryTypeIndex = memTypeIndex;
    allocInfo.allocationSize = size;

#if VMA_DEDICATED_ALLOCATION
    VkMemoryDedicatedAllocateInfoKHR dedicatedAllocInfo = { VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO_KHR };
    if(m_UseKhrDedicatedAllocation)
    {
        if(dedicatedBuffer != VK_NULL_HANDLE)
        {
            VMA_ASSERT(dedicatedImage == VK_NULL_HANDLE);
            dedicatedAllocInfo.buffer = dedicatedBuffer;
            allocInfo.pNext = &dedicatedAllocInfo;
        }
        else if(dedicatedImage != VK_NULL_HANDLE)
        {
            dedicatedAllocInfo.image = dedicatedImage;
            allocInfo.pNext = &dedicatedAllocInfo;
        }
    }
#endif // #if VMA_DEDICATED_ALLOCATION

    size_t allocIndex;
    VkResult res = VK_SUCCESS;
    for(allocIndex = 0; allocIndex < allocationCount; ++allocIndex)
    {
        res = AllocateDedicatedMemoryPage(
            size,
            suballocType,
            memTypeIndex,
            allocInfo,
            map,
            isUserDataString,
            pUserData,
            pAllocations + allocIndex);
        if(res != VK_SUCCESS)
        {
            break;
        }
    }

    if(res == VK_SUCCESS)
    {
        // Register them in m_pDedicatedAllocations.
        {
            VmaMutexLockWrite lock(m_DedicatedAllocationsMutex[memTypeIndex], m_UseMutex);
            AllocationVectorType* pDedicatedAllocations = m_pDedicatedAllocations[memTypeIndex];
            VMA_ASSERT(pDedicatedAllocations);
            for(allocIndex = 0; allocIndex < allocationCount; ++allocIndex)
            {
                VmaVectorInsertSorted<VmaPointerLess>(*pDedicatedAllocations, pAllocations[allocIndex]);
            }
        }

        VMA_DEBUG_LOG("    Allocated DedicatedMemory Count=%zu, MemoryTypeIndex=#%u", allocationCount, memTypeIndex);
    }
    else
    {
        // Free all already created allocations.
        while(allocIndex--)
        {
            VmaAllocation currAlloc = pAllocations[allocIndex];
            VkDeviceMemory hMemory = currAlloc->GetMemory();
    
            /*
            There is no need to call this, because Vulkan spec allows to skip vkUnmapMemory
            before vkFreeMemory.

            if(currAlloc->GetMappedData() != VMA_NULL)
            {
                (*m_VulkanFunctions.vkUnmapMemory)(m_hDevice, hMemory);
            }
            */
    
            FreeVulkanMemory(memTypeIndex, currAlloc->GetSize(), hMemory);

            currAlloc->SetUserData(this, VMA_NULL);
            currAlloc->Dtor();
            m_AllocationObjectAllocator.Free(currAlloc);
        }

        memset(pAllocations, 0, sizeof(VmaAllocation) * allocationCount);
    }

    return res;
}

VkResult VmaAllocator_T::AllocateDedicatedMemoryPage(
    VkDeviceSize size,
    VmaSuballocationType suballocType,
    uint32_t memTypeIndex,
    const VkMemoryAllocateInfo& allocInfo,
    bool map,
    bool isUserDataString,
    void* pUserData,
    VmaAllocation* pAllocation)
{
    VkDeviceMemory hMemory = VK_NULL_HANDLE;
    VkResult res = AllocateVulkanMemory(&allocInfo, &hMemory);
    if(res < 0)
    {
        VMA_DEBUG_LOG("    vkAllocateMemory FAILED");
        return res;
    }

    void* pMappedData = VMA_NULL;
    if(map)
    {
        res = (*m_VulkanFunctions.vkMapMemory)(
            m_hDevice,
            hMemory,
            0,
            VK_WHOLE_SIZE,
            0,
            &pMappedData);
        if(res < 0)
        {
            VMA_DEBUG_LOG("    vkMapMemory FAILED");
            FreeVulkanMemory(memTypeIndex, size, hMemory);
            return res;
        }
    }

    *pAllocation = m_AllocationObjectAllocator.Allocate();
    (*pAllocation)->Ctor(m_CurrentFrameIndex.load(), isUserDataString);
    (*pAllocation)->InitDedicatedAllocation(memTypeIndex, hMemory, suballocType, pMappedData, size);
    (*pAllocation)->SetUserData(this, pUserData);
    if(VMA_DEBUG_INITIALIZE_ALLOCATIONS)
    {
        FillAllocation(*pAllocation, VMA_ALLOCATION_FILL_PATTERN_CREATED);
    }

    return VK_SUCCESS;
}

void VmaAllocator_T::GetBufferMemoryRequirements(
    VkBuffer hBuffer,
    VkMemoryRequirements& memReq,
    bool& requiresDedicatedAllocation,
    bool& prefersDedicatedAllocation) const
{
#if VMA_DEDICATED_ALLOCATION
    if(m_UseKhrDedicatedAllocation)
    {
        VkBufferMemoryRequirementsInfo2KHR memReqInfo = { VK_STRUCTURE_TYPE_BUFFER_MEMORY_REQUIREMENTS_INFO_2_KHR };
        memReqInfo.buffer = hBuffer;

        VkMemoryDedicatedRequirementsKHR memDedicatedReq = { VK_STRUCTURE_TYPE_MEMORY_DEDICATED_REQUIREMENTS_KHR };

        VkMemoryRequirements2KHR memReq2 = { VK_STRUCTURE_TYPE_MEMORY_REQUIREMENTS_2_KHR };
        memReq2.pNext = &memDedicatedReq;

        (*m_VulkanFunctions.vkGetBufferMemoryRequirements2KHR)(m_hDevice, &memReqInfo, &memReq2);

        memReq = memReq2.memoryRequirements;
        requiresDedicatedAllocation = (memDedicatedReq.requiresDedicatedAllocation != VK_FALSE);
        prefersDedicatedAllocation  = (memDedicatedReq.prefersDedicatedAllocation  != VK_FALSE);
    }
    else
#endif // #if VMA_DEDICATED_ALLOCATION
    {
        (*m_VulkanFunctions.vkGetBufferMemoryRequirements)(m_hDevice, hBuffer, &memReq);
        requiresDedicatedAllocation = false;
        prefersDedicatedAllocation  = false;
    }
}

void VmaAllocator_T::GetImageMemoryRequirements(
    VkImage hImage,
    VkMemoryRequirements& memReq,
    bool& requiresDedicatedAllocation,
    bool& prefersDedicatedAllocation) const
{
#if VMA_DEDICATED_ALLOCATION
    if(m_UseKhrDedicatedAllocation)
    {
        VkImageMemoryRequirementsInfo2KHR memReqInfo = { VK_STRUCTURE_TYPE_IMAGE_MEMORY_REQUIREMENTS_INFO_2_KHR };
        memReqInfo.image = hImage;

        VkMemoryDedicatedRequirementsKHR memDedicatedReq = { VK_STRUCTURE_TYPE_MEMORY_DEDICATED_REQUIREMENTS_KHR };

        VkMemoryRequirements2KHR memReq2 = { VK_STRUCTURE_TYPE_MEMORY_REQUIREMENTS_2_KHR };
        memReq2.pNext = &memDedicatedReq;

        (*m_VulkanFunctions.vkGetImageMemoryRequirements2KHR)(m_hDevice, &memReqInfo, &memReq2);

        memReq = memReq2.memoryRequirements;
        requiresDedicatedAllocation = (memDedicatedReq.requiresDedicatedAllocation != VK_FALSE);
        prefersDedicatedAllocation  = (memDedicatedReq.prefersDedicatedAllocation  != VK_FALSE);
    }
    else
#endif // #if VMA_DEDICATED_ALLOCATION
    {
        (*m_VulkanFunctions.vkGetImageMemoryRequirements)(m_hDevice, hImage, &memReq);
        requiresDedicatedAllocation = false;
        prefersDedicatedAllocation  = false;
    }
}

VkResult VmaAllocator_T::AllocateMemory(
    const VkMemoryRequirements& vkMemReq,
    bool requiresDedicatedAllocation,
    bool prefersDedicatedAllocation,
    VkBuffer dedicatedBuffer,
    VkImage dedicatedImage,
    const VmaAllocationCreateInfo& createInfo,
    VmaSuballocationType suballocType,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{
    memset(pAllocations, 0, sizeof(VmaAllocation) * allocationCount);

    VMA_ASSERT(VmaIsPow2(vkMemReq.alignment));

    if(vkMemReq.size == 0)
    {
        return VK_ERROR_VALIDATION_FAILED_EXT;
    }
    if((createInfo.flags & VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT) != 0 &&
        (createInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) != 0)
    {
        VMA_ASSERT(0 && "Specifying VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT together with VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT makes no sense.");
        return VK_ERROR_OUT_OF_DEVICE_MEMORY;
    }
    if((createInfo.flags & VMA_ALLOCATION_CREATE_MAPPED_BIT) != 0 &&
        (createInfo.flags & VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT) != 0)
    {
        VMA_ASSERT(0 && "Specifying VMA_ALLOCATION_CREATE_MAPPED_BIT together with VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT is invalid.");
        return VK_ERROR_OUT_OF_DEVICE_MEMORY;
    }
    if(requiresDedicatedAllocation)
    {
        if((createInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) != 0)
        {
            VMA_ASSERT(0 && "VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT specified while dedicated allocation is required.");
            return VK_ERROR_OUT_OF_DEVICE_MEMORY;
        }
        if(createInfo.pool != VK_NULL_HANDLE)
        {
            VMA_ASSERT(0 && "Pool specified while dedicated allocation is required.");
            return VK_ERROR_OUT_OF_DEVICE_MEMORY;
        }
    }
    if((createInfo.pool != VK_NULL_HANDLE) &&
        ((createInfo.flags & (VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT)) != 0))
    {
        VMA_ASSERT(0 && "Specifying VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT when pool != null is invalid.");
        return VK_ERROR_OUT_OF_DEVICE_MEMORY;
    }

    if(createInfo.pool != VK_NULL_HANDLE)
    {
        const VkDeviceSize alignmentForPool = VMA_MAX(
            vkMemReq.alignment,
            GetMemoryTypeMinAlignment(createInfo.pool->m_BlockVector.GetMemoryTypeIndex()));
        return createInfo.pool->m_BlockVector.Allocate(
            m_CurrentFrameIndex.load(),
            vkMemReq.size,
            alignmentForPool,
            createInfo,
            suballocType,
            allocationCount,
            pAllocations);
    }
    else
    {
        // Bit mask of memory Vulkan types acceptable for this allocation.
        uint32_t memoryTypeBits = vkMemReq.memoryTypeBits;
        uint32_t memTypeIndex = UINT32_MAX;
        VkResult res = vmaFindMemoryTypeIndex(this, memoryTypeBits, &createInfo, &memTypeIndex);
        if(res == VK_SUCCESS)
        {
            VkDeviceSize alignmentForMemType = VMA_MAX(
                vkMemReq.alignment,
                GetMemoryTypeMinAlignment(memTypeIndex));

            res = AllocateMemoryOfType(
                vkMemReq.size,
                alignmentForMemType,
                requiresDedicatedAllocation || prefersDedicatedAllocation,
                dedicatedBuffer,
                dedicatedImage,
                createInfo,
                memTypeIndex,
                suballocType,
                allocationCount,
                pAllocations);
            // Succeeded on first try.
            if(res == VK_SUCCESS)
            {
                return res;
            }
            // Allocation from this memory type failed. Try other compatible memory types.
            else
            {
                for(;;)
                {
                    // Remove old memTypeIndex from list of possibilities.
                    memoryTypeBits &= ~(1u << memTypeIndex);
                    // Find alternative memTypeIndex.
                    res = vmaFindMemoryTypeIndex(this, memoryTypeBits, &createInfo, &memTypeIndex);
                    if(res == VK_SUCCESS)
                    {
                        alignmentForMemType = VMA_MAX(
                            vkMemReq.alignment,
                            GetMemoryTypeMinAlignment(memTypeIndex));
                        
                        res = AllocateMemoryOfType(
                            vkMemReq.size,
                            alignmentForMemType,
                            requiresDedicatedAllocation || prefersDedicatedAllocation,
                            dedicatedBuffer,
                            dedicatedImage,
                            createInfo,
                            memTypeIndex,
                            suballocType,
                            allocationCount,
                            pAllocations);
                        // Allocation from this alternative memory type succeeded.
                        if(res == VK_SUCCESS)
                        {
                            return res;
                        }
                        // else: Allocation from this memory type failed. Try next one - next loop iteration.
                    }
                    // No other matching memory type index could be found.
                    else
                    {
                        // Not returning res, which is VK_ERROR_FEATURE_NOT_PRESENT, because we already failed to allocate once.
                        return VK_ERROR_OUT_OF_DEVICE_MEMORY;
                    }
                }
            }
        }
        // Can't find any single memory type maching requirements. res is VK_ERROR_FEATURE_NOT_PRESENT.
        else
            return res;
    }
}

void VmaAllocator_T::FreeMemory(
    size_t allocationCount,
    const VmaAllocation* pAllocations)
{
    VMA_ASSERT(pAllocations);

    for(size_t allocIndex = allocationCount; allocIndex--; )
    {
        VmaAllocation allocation = pAllocations[allocIndex];

        if(allocation != VK_NULL_HANDLE)
        {
            if(TouchAllocation(allocation))
            {
                if(VMA_DEBUG_INITIALIZE_ALLOCATIONS)
                {
                    FillAllocation(allocation, VMA_ALLOCATION_FILL_PATTERN_DESTROYED);
                }

                switch(allocation->GetType())
                {
                case VmaAllocation_T::ALLOCATION_TYPE_BLOCK:
                    {
                        VmaBlockVector* pBlockVector = VMA_NULL;
                        VmaPool hPool = allocation->GetBlock()->GetParentPool();
                        if(hPool != VK_NULL_HANDLE)
                        {
                            pBlockVector = &hPool->m_BlockVector;
                        }
                        else
                        {
                            const uint32_t memTypeIndex = allocation->GetMemoryTypeIndex();
                            pBlockVector = m_pBlockVectors[memTypeIndex];
                        }
                        pBlockVector->Free(allocation);
                    }
                    break;
                case VmaAllocation_T::ALLOCATION_TYPE_DEDICATED:
                    FreeDedicatedMemory(allocation);
                    break;
                default:
                    VMA_ASSERT(0);
                }
            }

            allocation->SetUserData(this, VMA_NULL);
            allocation->Dtor();
            m_AllocationObjectAllocator.Free(allocation);
        }
    }
}

VkResult VmaAllocator_T::ResizeAllocation(
    const VmaAllocation alloc,
    VkDeviceSize newSize)
{
    if(newSize == 0 || alloc->GetLastUseFrameIndex() == VMA_FRAME_INDEX_LOST)
    {
        return VK_ERROR_VALIDATION_FAILED_EXT;
    }
    if(newSize == alloc->GetSize())
    {
        return VK_SUCCESS;
    }

    switch(alloc->GetType())
    {
    case VmaAllocation_T::ALLOCATION_TYPE_DEDICATED:
        return VK_ERROR_FEATURE_NOT_PRESENT;
    case VmaAllocation_T::ALLOCATION_TYPE_BLOCK:
        if(alloc->GetBlock()->m_pMetadata->ResizeAllocation(alloc, newSize))
        {
            alloc->ChangeSize(newSize);
            VMA_HEAVY_ASSERT(alloc->GetBlock()->m_pMetadata->Validate());
            return VK_SUCCESS;
        }
        else
        {
            return VK_ERROR_OUT_OF_POOL_MEMORY;
        }
    default:
        VMA_ASSERT(0);
        return VK_ERROR_VALIDATION_FAILED_EXT;
    }
}

void VmaAllocator_T::CalculateStats(VmaStats* pStats)
{
    // Initialize.
    InitStatInfo(pStats->total);
    for(size_t i = 0; i < VK_MAX_MEMORY_TYPES; ++i)
        InitStatInfo(pStats->memoryType[i]);
    for(size_t i = 0; i < VK_MAX_MEMORY_HEAPS; ++i)
        InitStatInfo(pStats->memoryHeap[i]);
    
    // Process default pools.
    for(uint32_t memTypeIndex = 0; memTypeIndex < GetMemoryTypeCount(); ++memTypeIndex)
    {
        VmaBlockVector* const pBlockVector = m_pBlockVectors[memTypeIndex];
        VMA_ASSERT(pBlockVector);
        pBlockVector->AddStats(pStats);
    }

    // Process custom pools.
    {
        VmaMutexLockRead lock(m_PoolsMutex, m_UseMutex);
        for(size_t poolIndex = 0, poolCount = m_Pools.size(); poolIndex < poolCount; ++poolIndex)
        {
            m_Pools[poolIndex]->m_BlockVector.AddStats(pStats);
        }
    }

    // Process dedicated allocations.
    for(uint32_t memTypeIndex = 0; memTypeIndex < GetMemoryTypeCount(); ++memTypeIndex)
    {
        const uint32_t memHeapIndex = MemoryTypeIndexToHeapIndex(memTypeIndex);
        VmaMutexLockRead dedicatedAllocationsLock(m_DedicatedAllocationsMutex[memTypeIndex], m_UseMutex);
        AllocationVectorType* const pDedicatedAllocVector = m_pDedicatedAllocations[memTypeIndex];
        VMA_ASSERT(pDedicatedAllocVector);
        for(size_t allocIndex = 0, allocCount = pDedicatedAllocVector->size(); allocIndex < allocCount; ++allocIndex)
        {
            VmaStatInfo allocationStatInfo;
            (*pDedicatedAllocVector)[allocIndex]->DedicatedAllocCalcStatsInfo(allocationStatInfo);
            VmaAddStatInfo(pStats->total, allocationStatInfo);
            VmaAddStatInfo(pStats->memoryType[memTypeIndex], allocationStatInfo);
            VmaAddStatInfo(pStats->memoryHeap[memHeapIndex], allocationStatInfo);
        }
    }

    // Postprocess.
    VmaPostprocessCalcStatInfo(pStats->total);
    for(size_t i = 0; i < GetMemoryTypeCount(); ++i)
        VmaPostprocessCalcStatInfo(pStats->memoryType[i]);
    for(size_t i = 0; i < GetMemoryHeapCount(); ++i)
        VmaPostprocessCalcStatInfo(pStats->memoryHeap[i]);
}

static const uint32_t VMA_VENDOR_ID_AMD = 4098;

VkResult VmaAllocator_T::DefragmentationBegin(
    const VmaDefragmentationInfo2& info,
    VmaDefragmentationStats* pStats,
    VmaDefragmentationContext* pContext)
{
    if(info.pAllocationsChanged != VMA_NULL)
    {
        memset(info.pAllocationsChanged, 0, info.allocationCount * sizeof(VkBool32));
    }

    *pContext = vma_new(this, VmaDefragmentationContext_T)(
        this, m_CurrentFrameIndex.load(), info.flags, pStats);

    (*pContext)->AddPools(info.poolCount, info.pPools);
    (*pContext)->AddAllocations(
        info.allocationCount, info.pAllocations, info.pAllocationsChanged);

    VkResult res = (*pContext)->Defragment(
        info.maxCpuBytesToMove, info.maxCpuAllocationsToMove,
        info.maxGpuBytesToMove, info.maxGpuAllocationsToMove,
        info.commandBuffer, pStats);

    if(res != VK_NOT_READY)
    {
        vma_delete(this, *pContext);
        *pContext = VMA_NULL;
    }

    return res;
}

VkResult VmaAllocator_T::DefragmentationEnd(
    VmaDefragmentationContext context)
{
    vma_delete(this, context);
    return VK_SUCCESS;
}

void VmaAllocator_T::GetAllocationInfo(VmaAllocation hAllocation, VmaAllocationInfo* pAllocationInfo)
{
    if(hAllocation->CanBecomeLost())
    {
        /*
        Warning: This is a carefully designed algorithm.
        Do not modify unless you really know what you're doing :)
        */
        const uint32_t localCurrFrameIndex = m_CurrentFrameIndex.load();
        uint32_t localLastUseFrameIndex = hAllocation->GetLastUseFrameIndex();
        for(;;)
        {
            if(localLastUseFrameIndex == VMA_FRAME_INDEX_LOST)
            {
                pAllocationInfo->memoryType = UINT32_MAX;
                pAllocationInfo->deviceMemory = VK_NULL_HANDLE;
                pAllocationInfo->offset = 0;
                pAllocationInfo->size = hAllocation->GetSize();
                pAllocationInfo->pMappedData = VMA_NULL;
                pAllocationInfo->pUserData = hAllocation->GetUserData();
                return;
            }
            else if(localLastUseFrameIndex == localCurrFrameIndex)
            {
                pAllocationInfo->memoryType = hAllocation->GetMemoryTypeIndex();
                pAllocationInfo->deviceMemory = hAllocation->GetMemory();
                pAllocationInfo->offset = hAllocation->GetOffset();
                pAllocationInfo->size = hAllocation->GetSize();
                pAllocationInfo->pMappedData = VMA_NULL;
                pAllocationInfo->pUserData = hAllocation->GetUserData();
                return;
            }
            else // Last use time earlier than current time.
            {
                if(hAllocation->CompareExchangeLastUseFrameIndex(localLastUseFrameIndex, localCurrFrameIndex))
                {
                    localLastUseFrameIndex = localCurrFrameIndex;
                }
            }
        }
    }
    else
    {
#if VMA_STATS_STRING_ENABLED
        uint32_t localCurrFrameIndex = m_CurrentFrameIndex.load();
        uint32_t localLastUseFrameIndex = hAllocation->GetLastUseFrameIndex();
        for(;;)
        {
            VMA_ASSERT(localLastUseFrameIndex != VMA_FRAME_INDEX_LOST);
            if(localLastUseFrameIndex == localCurrFrameIndex)
            {
                break;
            }
            else // Last use time earlier than current time.
            {
                if(hAllocation->CompareExchangeLastUseFrameIndex(localLastUseFrameIndex, localCurrFrameIndex))
                {
                    localLastUseFrameIndex = localCurrFrameIndex;
                }
            }
        }
#endif

        pAllocationInfo->memoryType = hAllocation->GetMemoryTypeIndex();
        pAllocationInfo->deviceMemory = hAllocation->GetMemory();
        pAllocationInfo->offset = hAllocation->GetOffset();
        pAllocationInfo->size = hAllocation->GetSize();
        pAllocationInfo->pMappedData = hAllocation->GetMappedData();
        pAllocationInfo->pUserData = hAllocation->GetUserData();
    }
}

bool VmaAllocator_T::TouchAllocation(VmaAllocation hAllocation)
{
    // This is a stripped-down version of VmaAllocator_T::GetAllocationInfo.
    if(hAllocation->CanBecomeLost())
    {
        uint32_t localCurrFrameIndex = m_CurrentFrameIndex.load();
        uint32_t localLastUseFrameIndex = hAllocation->GetLastUseFrameIndex();
        for(;;)
        {
            if(localLastUseFrameIndex == VMA_FRAME_INDEX_LOST)
            {
                return false;
            }
            else if(localLastUseFrameIndex == localCurrFrameIndex)
            {
                return true;
            }
            else // Last use time earlier than current time.
            {
                if(hAllocation->CompareExchangeLastUseFrameIndex(localLastUseFrameIndex, localCurrFrameIndex))
                {
                    localLastUseFrameIndex = localCurrFrameIndex;
                }
            }
        }
    }
    else
    {
#if VMA_STATS_STRING_ENABLED
        uint32_t localCurrFrameIndex = m_CurrentFrameIndex.load();
        uint32_t localLastUseFrameIndex = hAllocation->GetLastUseFrameIndex();
        for(;;)
        {
            VMA_ASSERT(localLastUseFrameIndex != VMA_FRAME_INDEX_LOST);
            if(localLastUseFrameIndex == localCurrFrameIndex)
            {
                break;
            }
            else // Last use time earlier than current time.
            {
                if(hAllocation->CompareExchangeLastUseFrameIndex(localLastUseFrameIndex, localCurrFrameIndex))
                {
                    localLastUseFrameIndex = localCurrFrameIndex;
                }
            }
        }
#endif

        return true;
    }
}

VkResult VmaAllocator_T::CreatePool(const VmaPoolCreateInfo* pCreateInfo, VmaPool* pPool)
{
    VMA_DEBUG_LOG("  CreatePool: MemoryTypeIndex=%u, flags=%u", pCreateInfo->memoryTypeIndex, pCreateInfo->flags);

    VmaPoolCreateInfo newCreateInfo = *pCreateInfo;

    if(newCreateInfo.maxBlockCount == 0)
    {
        newCreateInfo.maxBlockCount = SIZE_MAX;
    }
    if(newCreateInfo.minBlockCount > newCreateInfo.maxBlockCount)
    {
        return VK_ERROR_INITIALIZATION_FAILED;
    }

    const VkDeviceSize preferredBlockSize = CalcPreferredBlockSize(newCreateInfo.memoryTypeIndex);

    *pPool = vma_new(this, VmaPool_T)(this, newCreateInfo, preferredBlockSize);

    VkResult res = (*pPool)->m_BlockVector.CreateMinBlocks();
    if(res != VK_SUCCESS)
    {
        vma_delete(this, *pPool);
        *pPool = VMA_NULL;
        return res;
    }

    // Add to m_Pools.
    {
        VmaMutexLockWrite lock(m_PoolsMutex, m_UseMutex);
        (*pPool)->SetId(m_NextPoolId++);
        VmaVectorInsertSorted<VmaPointerLess>(m_Pools, *pPool);
    }

    return VK_SUCCESS;
}

void VmaAllocator_T::DestroyPool(VmaPool pool)
{
    // Remove from m_Pools.
    {
        VmaMutexLockWrite lock(m_PoolsMutex, m_UseMutex);
        bool success = VmaVectorRemoveSorted<VmaPointerLess>(m_Pools, pool);
        VMA_ASSERT(success && "Pool not found in Allocator.");
    }

    vma_delete(this, pool);
}

void VmaAllocator_T::GetPoolStats(VmaPool pool, VmaPoolStats* pPoolStats)
{
    pool->m_BlockVector.GetPoolStats(pPoolStats);
}

void VmaAllocator_T::SetCurrentFrameIndex(uint32_t frameIndex)
{
    m_CurrentFrameIndex.store(frameIndex);
}

void VmaAllocator_T::MakePoolAllocationsLost(
    VmaPool hPool,
    size_t* pLostAllocationCount)
{
    hPool->m_BlockVector.MakePoolAllocationsLost(
        m_CurrentFrameIndex.load(),
        pLostAllocationCount);
}

VkResult VmaAllocator_T::CheckPoolCorruption(VmaPool hPool)
{
    return hPool->m_BlockVector.CheckCorruption();
}

VkResult VmaAllocator_T::CheckCorruption(uint32_t memoryTypeBits)
{
    VkResult finalRes = VK_ERROR_FEATURE_NOT_PRESENT;

    // Process default pools.
    for(uint32_t memTypeIndex = 0; memTypeIndex < GetMemoryTypeCount(); ++memTypeIndex)
    {
        if(((1u << memTypeIndex) & memoryTypeBits) != 0)
        {
            VmaBlockVector* const pBlockVector = m_pBlockVectors[memTypeIndex];
            VMA_ASSERT(pBlockVector);
            VkResult localRes = pBlockVector->CheckCorruption();
            switch(localRes)
            {
            case VK_ERROR_FEATURE_NOT_PRESENT:
                break;
            case VK_SUCCESS:
                finalRes = VK_SUCCESS;
                break;
            default:
                return localRes;
            }
        }
    }

    // Process custom pools.
    {
        VmaMutexLockRead lock(m_PoolsMutex, m_UseMutex);
        for(size_t poolIndex = 0, poolCount = m_Pools.size(); poolIndex < poolCount; ++poolIndex)
        {
            if(((1u << m_Pools[poolIndex]->m_BlockVector.GetMemoryTypeIndex()) & memoryTypeBits) != 0)
            {
                VkResult localRes = m_Pools[poolIndex]->m_BlockVector.CheckCorruption();
                switch(localRes)
                {
                case VK_ERROR_FEATURE_NOT_PRESENT:
                    break;
                case VK_SUCCESS:
                    finalRes = VK_SUCCESS;
                    break;
                default:
                    return localRes;
                }
            }
        }
    }

    return finalRes;
}

void VmaAllocator_T::CreateLostAllocation(VmaAllocation* pAllocation)
{
    *pAllocation = m_AllocationObjectAllocator.Allocate();
    (*pAllocation)->Ctor(VMA_FRAME_INDEX_LOST, false);
    (*pAllocation)->InitLost();
}

VkResult VmaAllocator_T::AllocateVulkanMemory(const VkMemoryAllocateInfo* pAllocateInfo, VkDeviceMemory* pMemory)
{
    const uint32_t heapIndex = MemoryTypeIndexToHeapIndex(pAllocateInfo->memoryTypeIndex);

    VkResult res;
    if(m_HeapSizeLimit[heapIndex] != VK_WHOLE_SIZE)
    {
        VmaMutexLock lock(m_HeapSizeLimitMutex, m_UseMutex);
        if(m_HeapSizeLimit[heapIndex] >= pAllocateInfo->allocationSize)
        {
            res = (*m_VulkanFunctions.vkAllocateMemory)(m_hDevice, pAllocateInfo, GetAllocationCallbacks(), pMemory);
            if(res == VK_SUCCESS)
            {
                m_HeapSizeLimit[heapIndex] -= pAllocateInfo->allocationSize;
            }
        }
        else
        {
            res = VK_ERROR_OUT_OF_DEVICE_MEMORY;
        }
    }
    else
    {
        res = (*m_VulkanFunctions.vkAllocateMemory)(m_hDevice, pAllocateInfo, GetAllocationCallbacks(), pMemory);
    }

    if(res == VK_SUCCESS && m_DeviceMemoryCallbacks.pfnAllocate != VMA_NULL)
    {
        (*m_DeviceMemoryCallbacks.pfnAllocate)(this, pAllocateInfo->memoryTypeIndex, *pMemory, pAllocateInfo->allocationSize);
    }

    return res;
}

void VmaAllocator_T::FreeVulkanMemory(uint32_t memoryType, VkDeviceSize size, VkDeviceMemory hMemory)
{
    if(m_DeviceMemoryCallbacks.pfnFree != VMA_NULL)
    {
        (*m_DeviceMemoryCallbacks.pfnFree)(this, memoryType, hMemory, size);
    }

    (*m_VulkanFunctions.vkFreeMemory)(m_hDevice, hMemory, GetAllocationCallbacks());

    const uint32_t heapIndex = MemoryTypeIndexToHeapIndex(memoryType);
    if(m_HeapSizeLimit[heapIndex] != VK_WHOLE_SIZE)
    {
        VmaMutexLock lock(m_HeapSizeLimitMutex, m_UseMutex);
        m_HeapSizeLimit[heapIndex] += size;
    }
}

VkResult VmaAllocator_T::Map(VmaAllocation hAllocation, void** ppData)
{
    if(hAllocation->CanBecomeLost())
    {
        return VK_ERROR_MEMORY_MAP_FAILED;
    }

    switch(hAllocation->GetType())
    {
    case VmaAllocation_T::ALLOCATION_TYPE_BLOCK:
        {
            VmaDeviceMemoryBlock* const pBlock = hAllocation->GetBlock();
            char *pBytes = VMA_NULL;
            VkResult res = pBlock->Map(this, 1, (void**)&pBytes);
            if(res == VK_SUCCESS)
            {
                *ppData = pBytes + (ptrdiff_t)hAllocation->GetOffset();
                hAllocation->BlockAllocMap();
            }
            return res;
        }
    case VmaAllocation_T::ALLOCATION_TYPE_DEDICATED:
        return hAllocation->DedicatedAllocMap(this, ppData);
    default:
        VMA_ASSERT(0);
        return VK_ERROR_MEMORY_MAP_FAILED;
    }
}

void VmaAllocator_T::Unmap(VmaAllocation hAllocation)
{
    switch(hAllocation->GetType())
    {
    case VmaAllocation_T::ALLOCATION_TYPE_BLOCK:
        {
            VmaDeviceMemoryBlock* const pBlock = hAllocation->GetBlock();
            hAllocation->BlockAllocUnmap();
            pBlock->Unmap(this, 1);
        }
        break;
    case VmaAllocation_T::ALLOCATION_TYPE_DEDICATED:
        hAllocation->DedicatedAllocUnmap(this);
        break;
    default:
        VMA_ASSERT(0);
    }
}

VkResult VmaAllocator_T::BindBufferMemory(VmaAllocation hAllocation, VkBuffer hBuffer)
{
    VkResult res = VK_SUCCESS;
    switch(hAllocation->GetType())
    {
    case VmaAllocation_T::ALLOCATION_TYPE_DEDICATED:
        res = GetVulkanFunctions().vkBindBufferMemory(
            m_hDevice,
            hBuffer,
            hAllocation->GetMemory(),
            0); //memoryOffset
        break;
    case VmaAllocation_T::ALLOCATION_TYPE_BLOCK:
    {
        VmaDeviceMemoryBlock* pBlock = hAllocation->GetBlock();
        VMA_ASSERT(pBlock && "Binding buffer to allocation that doesn't belong to any block. Is the allocation lost?");
        res = pBlock->BindBufferMemory(this, hAllocation, hBuffer);
        break;
    }
    default:
        VMA_ASSERT(0);
    }
    return res;
}

VkResult VmaAllocator_T::BindImageMemory(VmaAllocation hAllocation, VkImage hImage)
{
    VkResult res = VK_SUCCESS;
    switch(hAllocation->GetType())
    {
    case VmaAllocation_T::ALLOCATION_TYPE_DEDICATED:
        res = GetVulkanFunctions().vkBindImageMemory(
            m_hDevice,
            hImage,
            hAllocation->GetMemory(),
            0); //memoryOffset
        break;
    case VmaAllocation_T::ALLOCATION_TYPE_BLOCK:
    {
        VmaDeviceMemoryBlock* pBlock = hAllocation->GetBlock();
        VMA_ASSERT(pBlock && "Binding image to allocation that doesn't belong to any block. Is the allocation lost?");
        res = pBlock->BindImageMemory(this, hAllocation, hImage);
        break;
    }
    default:
        VMA_ASSERT(0);
    }
    return res;
}

void VmaAllocator_T::FlushOrInvalidateAllocation(
    VmaAllocation hAllocation,
    VkDeviceSize offset, VkDeviceSize size,
    VMA_CACHE_OPERATION op)
{
    const uint32_t memTypeIndex = hAllocation->GetMemoryTypeIndex();
    if(size > 0 && IsMemoryTypeNonCoherent(memTypeIndex))
    {
        const VkDeviceSize allocationSize = hAllocation->GetSize();
        VMA_ASSERT(offset <= allocationSize);

        const VkDeviceSize nonCoherentAtomSize = m_PhysicalDeviceProperties.limits.nonCoherentAtomSize;

        VkMappedMemoryRange memRange = { VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE };
        memRange.memory = hAllocation->GetMemory();
        
        switch(hAllocation->GetType())
        {
        case VmaAllocation_T::ALLOCATION_TYPE_DEDICATED:
            memRange.offset = VmaAlignDown(offset, nonCoherentAtomSize);
            if(size == VK_WHOLE_SIZE)
            {
                memRange.size = allocationSize - memRange.offset;
            }
            else
            {
                VMA_ASSERT(offset + size <= allocationSize);
                memRange.size = VMA_MIN(
                    VmaAlignUp(size + (offset - memRange.offset), nonCoherentAtomSize),
                    allocationSize - memRange.offset);
            }
            break;

        case VmaAllocation_T::ALLOCATION_TYPE_BLOCK:
        {
            // 1. Still within this allocation.
            memRange.offset = VmaAlignDown(offset, nonCoherentAtomSize);
            if(size == VK_WHOLE_SIZE)
            {
                size = allocationSize - offset;
            }
            else
            {
                VMA_ASSERT(offset + size <= allocationSize);
            }
            memRange.size = VmaAlignUp(size + (offset - memRange.offset), nonCoherentAtomSize);

            // 2. Adjust to whole block.
            const VkDeviceSize allocationOffset = hAllocation->GetOffset();
            VMA_ASSERT(allocationOffset % nonCoherentAtomSize == 0);
            const VkDeviceSize blockSize = hAllocation->GetBlock()->m_pMetadata->GetSize();
            memRange.offset += allocationOffset;
            memRange.size = VMA_MIN(memRange.size, blockSize - memRange.offset);
            
            break;
        }
        
        default:
            VMA_ASSERT(0);
        }

        switch(op)
        {
        case VMA_CACHE_FLUSH:
            (*GetVulkanFunctions().vkFlushMappedMemoryRanges)(m_hDevice, 1, &memRange);
            break;
        case VMA_CACHE_INVALIDATE:
            (*GetVulkanFunctions().vkInvalidateMappedMemoryRanges)(m_hDevice, 1, &memRange);
            break;
        default:
            VMA_ASSERT(0);
        }
    }
    // else: Just ignore this call.
}

void VmaAllocator_T::FreeDedicatedMemory(VmaAllocation allocation)
{
    VMA_ASSERT(allocation && allocation->GetType() == VmaAllocation_T::ALLOCATION_TYPE_DEDICATED);

    const uint32_t memTypeIndex = allocation->GetMemoryTypeIndex();
    {
        VmaMutexLockWrite lock(m_DedicatedAllocationsMutex[memTypeIndex], m_UseMutex);
        AllocationVectorType* const pDedicatedAllocations = m_pDedicatedAllocations[memTypeIndex];
        VMA_ASSERT(pDedicatedAllocations);
        bool success = VmaVectorRemoveSorted<VmaPointerLess>(*pDedicatedAllocations, allocation);
        VMA_ASSERT(success);
    }

    VkDeviceMemory hMemory = allocation->GetMemory();
    
    /*
    There is no need to call this, because Vulkan spec allows to skip vkUnmapMemory
    before vkFreeMemory.

    if(allocation->GetMappedData() != VMA_NULL)
    {
        (*m_VulkanFunctions.vkUnmapMemory)(m_hDevice, hMemory);
    }
    */
    
    FreeVulkanMemory(memTypeIndex, allocation->GetSize(), hMemory);

    VMA_DEBUG_LOG("    Freed DedicatedMemory MemoryTypeIndex=%u", memTypeIndex);
}

uint32_t VmaAllocator_T::CalculateGpuDefragmentationMemoryTypeBits() const
{
    VkBufferCreateInfo dummyBufCreateInfo;
    VmaFillGpuDefragmentationBufferCreateInfo(dummyBufCreateInfo);

    uint32_t memoryTypeBits = 0;

    // Create buffer.
    VkBuffer buf = VMA_NULL;
    VkResult res = (*GetVulkanFunctions().vkCreateBuffer)(
        m_hDevice, &dummyBufCreateInfo, GetAllocationCallbacks(), &buf);
    if(res == VK_SUCCESS)
    {
        // Query for supported memory types.
        VkMemoryRequirements memReq;
        (*GetVulkanFunctions().vkGetBufferMemoryRequirements)(m_hDevice, buf, &memReq);
        memoryTypeBits = memReq.memoryTypeBits;

        // Destroy buffer.
        (*GetVulkanFunctions().vkDestroyBuffer)(m_hDevice, buf, GetAllocationCallbacks());
    }

    return memoryTypeBits;
}

void VmaAllocator_T::FillAllocation(const VmaAllocation hAllocation, uint8_t pattern)
{
    if(VMA_DEBUG_INITIALIZE_ALLOCATIONS &&
        !hAllocation->CanBecomeLost() &&
        (m_MemProps.memoryTypes[hAllocation->GetMemoryTypeIndex()].propertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) != 0)
    {
        void* pData = VMA_NULL;
        VkResult res = Map(hAllocation, &pData);
        if(res == VK_SUCCESS)
        {
            memset(pData, (int)pattern, (size_t)hAllocation->GetSize());
            FlushOrInvalidateAllocation(hAllocation, 0, VK_WHOLE_SIZE, VMA_CACHE_FLUSH);
            Unmap(hAllocation);
        }
        else
        {
            VMA_ASSERT(0 && "VMA_DEBUG_INITIALIZE_ALLOCATIONS is enabled, but couldn't map memory to fill allocation.");
        }
    }
}

uint32_t VmaAllocator_T::GetGpuDefragmentationMemoryTypeBits()
{
    uint32_t memoryTypeBits = m_GpuDefragmentationMemoryTypeBits.load();
    if(memoryTypeBits == UINT32_MAX)
    {
        memoryTypeBits = CalculateGpuDefragmentationMemoryTypeBits();
        m_GpuDefragmentationMemoryTypeBits.store(memoryTypeBits);
    }
    return memoryTypeBits;
}

#if VMA_STATS_STRING_ENABLED

void VmaAllocator_T::PrintDetailedMap(VmaJsonWriter& json)
{
    bool dedicatedAllocationsStarted = false;
    for(uint32_t memTypeIndex = 0; memTypeIndex < GetMemoryTypeCount(); ++memTypeIndex)
    {
        VmaMutexLockRead dedicatedAllocationsLock(m_DedicatedAllocationsMutex[memTypeIndex], m_UseMutex);
        AllocationVectorType* const pDedicatedAllocVector = m_pDedicatedAllocations[memTypeIndex];
        VMA_ASSERT(pDedicatedAllocVector);
        if(pDedicatedAllocVector->empty() == false)
        {
            if(dedicatedAllocationsStarted == false)
            {
                dedicatedAllocationsStarted = true;
                json.WriteString("DedicatedAllocations");
                json.BeginObject();
            }

            json.BeginString("Type ");
            json.ContinueString(memTypeIndex);
            json.EndString();
                
            json.BeginArray();

            for(size_t i = 0; i < pDedicatedAllocVector->size(); ++i)
            {
                json.BeginObject(true);
                const VmaAllocation hAlloc = (*pDedicatedAllocVector)[i];
                hAlloc->PrintParameters(json);
                json.EndObject();
            }

            json.EndArray();
        }
    }
    if(dedicatedAllocationsStarted)
    {
        json.EndObject();
    }

    {
        bool allocationsStarted = false;
        for(uint32_t memTypeIndex = 0; memTypeIndex < GetMemoryTypeCount(); ++memTypeIndex)
        {
            if(m_pBlockVectors[memTypeIndex]->IsEmpty() == false)
            {
                if(allocationsStarted == false)
                {
                    allocationsStarted = true;
                    json.WriteString("DefaultPools");
                    json.BeginObject();
                }

                json.BeginString("Type ");
                json.ContinueString(memTypeIndex);
                json.EndString();

                m_pBlockVectors[memTypeIndex]->PrintDetailedMap(json);
            }
        }
        if(allocationsStarted)
        {
            json.EndObject();
        }
    }

    // Custom pools
    {
        VmaMutexLockRead lock(m_PoolsMutex, m_UseMutex);
        const size_t poolCount = m_Pools.size();
        if(poolCount > 0)
        {
            json.WriteString("Pools");
            json.BeginObject();
            for(size_t poolIndex = 0; poolIndex < poolCount; ++poolIndex)
            {
                json.BeginString();
                json.ContinueString(m_Pools[poolIndex]->GetId());
                json.EndString();

                m_Pools[poolIndex]->m_BlockVector.PrintDetailedMap(json);
            }
            json.EndObject();
        }
    }
}

#endif // #if VMA_STATS_STRING_ENABLED

// Public interface

VkResult vmaCreateAllocator(
    const VmaAllocatorCreateInfo* pCreateInfo,
    VmaAllocator* pAllocator)
{
    VMA_ASSERT(pCreateInfo && pAllocator);
    VMA_DEBUG_LOG("vmaCreateAllocator");
    *pAllocator = vma_new(pCreateInfo->pAllocationCallbacks, VmaAllocator_T)(pCreateInfo);
    return (*pAllocator)->Init(pCreateInfo);
}

void vmaDestroyAllocator(
    VmaAllocator allocator)
{
    if(allocator != VK_NULL_HANDLE)
    {
        VMA_DEBUG_LOG("vmaDestroyAllocator");
        VkAllocationCallbacks allocationCallbacks = allocator->m_AllocationCallbacks;
        vma_delete(&allocationCallbacks, allocator);
    }
}

void vmaGetPhysicalDeviceProperties(
    VmaAllocator allocator,
    const VkPhysicalDeviceProperties **ppPhysicalDeviceProperties)
{
    VMA_ASSERT(allocator && ppPhysicalDeviceProperties);
    *ppPhysicalDeviceProperties = &allocator->m_PhysicalDeviceProperties;
}

void vmaGetMemoryProperties(
    VmaAllocator allocator,
    const VkPhysicalDeviceMemoryProperties** ppPhysicalDeviceMemoryProperties)
{
    VMA_ASSERT(allocator && ppPhysicalDeviceMemoryProperties);
    *ppPhysicalDeviceMemoryProperties = &allocator->m_MemProps;
}

void vmaGetMemoryTypeProperties(
    VmaAllocator allocator,
    uint32_t memoryTypeIndex,
    VkMemoryPropertyFlags* pFlags)
{
    VMA_ASSERT(allocator && pFlags);
    VMA_ASSERT(memoryTypeIndex < allocator->GetMemoryTypeCount());
    *pFlags = allocator->m_MemProps.memoryTypes[memoryTypeIndex].propertyFlags;
}

void vmaSetCurrentFrameIndex(
    VmaAllocator allocator,
    uint32_t frameIndex)
{
    VMA_ASSERT(allocator);
    VMA_ASSERT(frameIndex != VMA_FRAME_INDEX_LOST);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    allocator->SetCurrentFrameIndex(frameIndex);
}

void vmaCalculateStats(
    VmaAllocator allocator,
    VmaStats* pStats)
{
    VMA_ASSERT(allocator && pStats);
    VMA_DEBUG_GLOBAL_MUTEX_LOCK
    allocator->CalculateStats(pStats);
}

#if VMA_STATS_STRING_ENABLED

void vmaBuildStatsString(
    VmaAllocator allocator,
    char** ppStatsString,
    VkBool32 detailedMap)
{
    VMA_ASSERT(allocator && ppStatsString);
    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VmaStringBuilder sb(allocator);
    {
        VmaJsonWriter json(allocator->GetAllocationCallbacks(), sb);
        json.BeginObject();

        VmaStats stats;
        allocator->CalculateStats(&stats);

        json.WriteString("Total");
        VmaPrintStatInfo(json, stats.total);
    
        for(uint32_t heapIndex = 0; heapIndex < allocator->GetMemoryHeapCount(); ++heapIndex)
        {
            json.BeginString("Heap ");
            json.ContinueString(heapIndex);
            json.EndString();
            json.BeginObject();

            json.WriteString("Size");
            json.WriteNumber(allocator->m_MemProps.memoryHeaps[heapIndex].size);

            json.WriteString("Flags");
            json.BeginArray(true);
            if((allocator->m_MemProps.memoryHeaps[heapIndex].flags & VK_MEMORY_HEAP_DEVICE_LOCAL_BIT) != 0)
            {
                json.WriteString("DEVICE_LOCAL");
            }
            json.EndArray();

            if(stats.memoryHeap[heapIndex].blockCount > 0)
            {
                json.WriteString("Stats");
                VmaPrintStatInfo(json, stats.memoryHeap[heapIndex]);
            }

            for(uint32_t typeIndex = 0; typeIndex < allocator->GetMemoryTypeCount(); ++typeIndex)
            {
                if(allocator->MemoryTypeIndexToHeapIndex(typeIndex) == heapIndex)
                {
                    json.BeginString("Type ");
                    json.ContinueString(typeIndex);
                    json.EndString();

                    json.BeginObject();

                    json.WriteString("Flags");
                    json.BeginArray(true);
                    VkMemoryPropertyFlags flags = allocator->m_MemProps.memoryTypes[typeIndex].propertyFlags;
                    if((flags & VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT) != 0)
                    {
                        json.WriteString("DEVICE_LOCAL");
                    }
                    if((flags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) != 0)
                    {
                        json.WriteString("HOST_VISIBLE");
                    }
                    if((flags & VK_MEMORY_PROPERTY_HOST_COHERENT_BIT) != 0)
                    {
                        json.WriteString("HOST_COHERENT");
                    }
                    if((flags & VK_MEMORY_PROPERTY_HOST_CACHED_BIT) != 0)
                    {
                        json.WriteString("HOST_CACHED");
                    }
                    if((flags & VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT) != 0)
                    {
                        json.WriteString("LAZILY_ALLOCATED");
                    }
                    json.EndArray();

                    if(stats.memoryType[typeIndex].blockCount > 0)
                    {
                        json.WriteString("Stats");
                        VmaPrintStatInfo(json, stats.memoryType[typeIndex]);
                    }

                    json.EndObject();
                }
            }

            json.EndObject();
        }
        if(detailedMap == VK_TRUE)
        {
            allocator->PrintDetailedMap(json);
        }

        json.EndObject();
    }

    const size_t len = sb.GetLength();
    char* const pChars = vma_new_array(allocator, char, len + 1);
    if(len > 0)
    {
        memcpy(pChars, sb.GetData(), len);
    }
    pChars[len] = '\0';
    *ppStatsString = pChars;
}

void vmaFreeStatsString(
    VmaAllocator allocator,
    char* pStatsString)
{
    if(pStatsString != VMA_NULL)
    {
        VMA_ASSERT(allocator);
        size_t len = strlen(pStatsString);
        vma_delete_array(allocator, pStatsString, len + 1);
    }
}

#endif // #if VMA_STATS_STRING_ENABLED

/*
This function is not protected by any mutex because it just reads immutable data.
*/
VkResult vmaFindMemoryTypeIndex(
    VmaAllocator allocator,
    uint32_t memoryTypeBits,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex)
{
    VMA_ASSERT(allocator != VK_NULL_HANDLE);
    VMA_ASSERT(pAllocationCreateInfo != VMA_NULL);
    VMA_ASSERT(pMemoryTypeIndex != VMA_NULL);

    if(pAllocationCreateInfo->memoryTypeBits != 0)
    {
        memoryTypeBits &= pAllocationCreateInfo->memoryTypeBits;
    }
    
    uint32_t requiredFlags = pAllocationCreateInfo->requiredFlags;
    uint32_t preferredFlags = pAllocationCreateInfo->preferredFlags;

    // Convert usage to requiredFlags and preferredFlags.
    switch(pAllocationCreateInfo->usage)
    {
    case VMA_MEMORY_USAGE_UNKNOWN:
        break;
    case VMA_MEMORY_USAGE_GPU_ONLY:
        if(!allocator->IsIntegratedGpu() || (preferredFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) == 0)
        {
            preferredFlags |= VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
        }
        break;
    case VMA_MEMORY_USAGE_CPU_ONLY:
        requiredFlags |= VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
        break;
    case VMA_MEMORY_USAGE_CPU_TO_GPU:
        requiredFlags |= VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT;
        if(!allocator->IsIntegratedGpu() || (preferredFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) == 0)
        {
            preferredFlags |= VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
        }
        break;
    case VMA_MEMORY_USAGE_GPU_TO_CPU:
        requiredFlags |= VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT;
        preferredFlags |= VK_MEMORY_PROPERTY_HOST_COHERENT_BIT | VK_MEMORY_PROPERTY_HOST_CACHED_BIT;
        break;
    default:
        break;
    }

    *pMemoryTypeIndex = UINT32_MAX;
    uint32_t minCost = UINT32_MAX;
    for(uint32_t memTypeIndex = 0, memTypeBit = 1;
        memTypeIndex < allocator->GetMemoryTypeCount();
        ++memTypeIndex, memTypeBit <<= 1)
    {
        // This memory type is acceptable according to memoryTypeBits bitmask.
        if((memTypeBit & memoryTypeBits) != 0)
        {
            const VkMemoryPropertyFlags currFlags =
                allocator->m_MemProps.memoryTypes[memTypeIndex].propertyFlags;
            // This memory type contains requiredFlags.
            if((requiredFlags & ~currFlags) == 0)
            {
                // Calculate cost as number of bits from preferredFlags not present in this memory type.
                uint32_t currCost = VmaCountBitsSet(preferredFlags & ~currFlags);
                // Remember memory type with lowest cost.
                if(currCost < minCost)
                {
                    *pMemoryTypeIndex = memTypeIndex;
                    if(currCost == 0)
                    {
                        return VK_SUCCESS;
                    }
                    minCost = currCost;
                }
            }
        }
    }
    return (*pMemoryTypeIndex != UINT32_MAX) ? VK_SUCCESS : VK_ERROR_FEATURE_NOT_PRESENT;
}

VkResult vmaFindMemoryTypeIndexForBufferInfo(
    VmaAllocator allocator,
    const VkBufferCreateInfo* pBufferCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex)
{
    VMA_ASSERT(allocator != VK_NULL_HANDLE);
    VMA_ASSERT(pBufferCreateInfo != VMA_NULL);
    VMA_ASSERT(pAllocationCreateInfo != VMA_NULL);
    VMA_ASSERT(pMemoryTypeIndex != VMA_NULL);

    const VkDevice hDev = allocator->m_hDevice;
    VkBuffer hBuffer = VK_NULL_HANDLE;
    VkResult res = allocator->GetVulkanFunctions().vkCreateBuffer(
        hDev, pBufferCreateInfo, allocator->GetAllocationCallbacks(), &hBuffer);
    if(res == VK_SUCCESS)
    {
        VkMemoryRequirements memReq = {};
        allocator->GetVulkanFunctions().vkGetBufferMemoryRequirements(
            hDev, hBuffer, &memReq);

        res = vmaFindMemoryTypeIndex(
            allocator,
            memReq.memoryTypeBits,
            pAllocationCreateInfo,
            pMemoryTypeIndex);

        allocator->GetVulkanFunctions().vkDestroyBuffer(
            hDev, hBuffer, allocator->GetAllocationCallbacks());
    }
    return res;
}

VkResult vmaFindMemoryTypeIndexForImageInfo(
    VmaAllocator allocator,
    const VkImageCreateInfo* pImageCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex)
{
    VMA_ASSERT(allocator != VK_NULL_HANDLE);
    VMA_ASSERT(pImageCreateInfo != VMA_NULL);
    VMA_ASSERT(pAllocationCreateInfo != VMA_NULL);
    VMA_ASSERT(pMemoryTypeIndex != VMA_NULL);

    const VkDevice hDev = allocator->m_hDevice;
    VkImage hImage = VK_NULL_HANDLE;
    VkResult res = allocator->GetVulkanFunctions().vkCreateImage(
        hDev, pImageCreateInfo, allocator->GetAllocationCallbacks(), &hImage);
    if(res == VK_SUCCESS)
    {
        VkMemoryRequirements memReq = {};
        allocator->GetVulkanFunctions().vkGetImageMemoryRequirements(
            hDev, hImage, &memReq);

        res = vmaFindMemoryTypeIndex(
            allocator,
            memReq.memoryTypeBits,
            pAllocationCreateInfo,
            pMemoryTypeIndex);

        allocator->GetVulkanFunctions().vkDestroyImage(
            hDev, hImage, allocator->GetAllocationCallbacks());
    }
    return res;
}

VkResult vmaCreatePool(
    VmaAllocator allocator,
    const VmaPoolCreateInfo* pCreateInfo,
    VmaPool* pPool)
{
    VMA_ASSERT(allocator && pCreateInfo && pPool);
    
    VMA_DEBUG_LOG("vmaCreatePool");
    
    VMA_DEBUG_GLOBAL_MUTEX_LOCK
    
    VkResult res = allocator->CreatePool(pCreateInfo, pPool);
    
#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordCreatePool(allocator->GetCurrentFrameIndex(), *pCreateInfo, *pPool);
    }
#endif
    
    return res;
}

void vmaDestroyPool(
    VmaAllocator allocator,
    VmaPool pool)
{
    VMA_ASSERT(allocator);
    
    if(pool == VK_NULL_HANDLE)
    {
        return;
    }
    
    VMA_DEBUG_LOG("vmaDestroyPool");
    
    VMA_DEBUG_GLOBAL_MUTEX_LOCK
    
#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordDestroyPool(allocator->GetCurrentFrameIndex(), pool);
    }
#endif

    allocator->DestroyPool(pool);
}

void vmaGetPoolStats(
    VmaAllocator allocator,
    VmaPool pool,
    VmaPoolStats* pPoolStats)
{
    VMA_ASSERT(allocator && pool && pPoolStats);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    allocator->GetPoolStats(pool, pPoolStats);
}

void vmaMakePoolAllocationsLost(
    VmaAllocator allocator,
    VmaPool pool,
    size_t* pLostAllocationCount)
{
    VMA_ASSERT(allocator && pool);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordMakePoolAllocationsLost(allocator->GetCurrentFrameIndex(), pool);
    }
#endif

    allocator->MakePoolAllocationsLost(pool, pLostAllocationCount);
}

VkResult vmaCheckPoolCorruption(VmaAllocator allocator, VmaPool pool)
{
    VMA_ASSERT(allocator && pool);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VMA_DEBUG_LOG("vmaCheckPoolCorruption");

    return allocator->CheckPoolCorruption(pool);
}

VkResult vmaAllocateMemory(
    VmaAllocator allocator,
    const VkMemoryRequirements* pVkMemoryRequirements,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{
    VMA_ASSERT(allocator && pVkMemoryRequirements && pCreateInfo && pAllocation);

    VMA_DEBUG_LOG("vmaAllocateMemory");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VkResult result = allocator->AllocateMemory(
        *pVkMemoryRequirements,
        false, // requiresDedicatedAllocation
        false, // prefersDedicatedAllocation
        VK_NULL_HANDLE, // dedicatedBuffer
        VK_NULL_HANDLE, // dedicatedImage
        *pCreateInfo,
        VMA_SUBALLOCATION_TYPE_UNKNOWN,
        1, // allocationCount
        pAllocation);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordAllocateMemory(
            allocator->GetCurrentFrameIndex(),
            *pVkMemoryRequirements,
            *pCreateInfo,
            *pAllocation);
    }
#endif
        
    if(pAllocationInfo != VMA_NULL && result == VK_SUCCESS)
    {
        allocator->GetAllocationInfo(*pAllocation, pAllocationInfo);
    }

    return result;
}

VkResult vmaAllocateMemoryPages(
    VmaAllocator allocator,
    const VkMemoryRequirements* pVkMemoryRequirements,
    const VmaAllocationCreateInfo* pCreateInfo,
    size_t allocationCount,
    VmaAllocation* pAllocations,
    VmaAllocationInfo* pAllocationInfo)
{
    if(allocationCount == 0)
    {
        return VK_SUCCESS;
    }

    VMA_ASSERT(allocator && pVkMemoryRequirements && pCreateInfo && pAllocations);

    VMA_DEBUG_LOG("vmaAllocateMemoryPages");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VkResult result = allocator->AllocateMemory(
        *pVkMemoryRequirements,
        false, // requiresDedicatedAllocation
        false, // prefersDedicatedAllocation
        VK_NULL_HANDLE, // dedicatedBuffer
        VK_NULL_HANDLE, // dedicatedImage
        *pCreateInfo,
        VMA_SUBALLOCATION_TYPE_UNKNOWN,
        allocationCount,
        pAllocations);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordAllocateMemoryPages(
            allocator->GetCurrentFrameIndex(),
            *pVkMemoryRequirements,
            *pCreateInfo,
            (uint64_t)allocationCount,
            pAllocations);
    }
#endif
        
    if(pAllocationInfo != VMA_NULL && result == VK_SUCCESS)
    {
        for(size_t i = 0; i < allocationCount; ++i)
        {
            allocator->GetAllocationInfo(pAllocations[i], pAllocationInfo + i);
        }
    }

    return result;
}

VkResult vmaAllocateMemoryForBuffer(
    VmaAllocator allocator,
    VkBuffer buffer,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{
    VMA_ASSERT(allocator && buffer != VK_NULL_HANDLE && pCreateInfo && pAllocation);

    VMA_DEBUG_LOG("vmaAllocateMemoryForBuffer");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VkMemoryRequirements vkMemReq = {};
    bool requiresDedicatedAllocation = false;
    bool prefersDedicatedAllocation = false;
    allocator->GetBufferMemoryRequirements(buffer, vkMemReq,
        requiresDedicatedAllocation,
        prefersDedicatedAllocation);

    VkResult result = allocator->AllocateMemory(
        vkMemReq,
        requiresDedicatedAllocation,
        prefersDedicatedAllocation,
        buffer, // dedicatedBuffer
        VK_NULL_HANDLE, // dedicatedImage
        *pCreateInfo,
        VMA_SUBALLOCATION_TYPE_BUFFER,
        1, // allocationCount
        pAllocation);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordAllocateMemoryForBuffer(
            allocator->GetCurrentFrameIndex(),
            vkMemReq,
            requiresDedicatedAllocation,
            prefersDedicatedAllocation,
            *pCreateInfo,
            *pAllocation);
    }
#endif

    if(pAllocationInfo && result == VK_SUCCESS)
    {
        allocator->GetAllocationInfo(*pAllocation, pAllocationInfo);
    }

    return result;
}

VkResult vmaAllocateMemoryForImage(
    VmaAllocator allocator,
    VkImage image,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{
    VMA_ASSERT(allocator && image != VK_NULL_HANDLE && pCreateInfo && pAllocation);

    VMA_DEBUG_LOG("vmaAllocateMemoryForImage");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VkMemoryRequirements vkMemReq = {};
    bool requiresDedicatedAllocation = false;
    bool prefersDedicatedAllocation  = false;
    allocator->GetImageMemoryRequirements(image, vkMemReq,
        requiresDedicatedAllocation, prefersDedicatedAllocation);

    VkResult result = allocator->AllocateMemory(
        vkMemReq,
        requiresDedicatedAllocation,
        prefersDedicatedAllocation,
        VK_NULL_HANDLE, // dedicatedBuffer
        image, // dedicatedImage
        *pCreateInfo,
        VMA_SUBALLOCATION_TYPE_IMAGE_UNKNOWN,
        1, // allocationCount
        pAllocation);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordAllocateMemoryForImage(
            allocator->GetCurrentFrameIndex(),
            vkMemReq,
            requiresDedicatedAllocation,
            prefersDedicatedAllocation,
            *pCreateInfo,
            *pAllocation);
    }
#endif

    if(pAllocationInfo && result == VK_SUCCESS)
    {
        allocator->GetAllocationInfo(*pAllocation, pAllocationInfo);
    }

    return result;
}

void vmaFreeMemory(
    VmaAllocator allocator,
    VmaAllocation allocation)
{
    VMA_ASSERT(allocator);
    
    if(allocation == VK_NULL_HANDLE)
    {
        return;
    }
    
    VMA_DEBUG_LOG("vmaFreeMemory");
    
    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordFreeMemory(
            allocator->GetCurrentFrameIndex(),
            allocation);
    }
#endif
    
    allocator->FreeMemory(
        1, // allocationCount
        &allocation);
}

void vmaFreeMemoryPages(
    VmaAllocator allocator,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{
    if(allocationCount == 0)
    {
        return;
    }

    VMA_ASSERT(allocator);
    
    VMA_DEBUG_LOG("vmaFreeMemoryPages");
    
    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordFreeMemoryPages(
            allocator->GetCurrentFrameIndex(),
            (uint64_t)allocationCount,
            pAllocations);
    }
#endif
    
    allocator->FreeMemory(allocationCount, pAllocations);
}

VkResult vmaResizeAllocation(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkDeviceSize newSize)
{
    VMA_ASSERT(allocator && allocation);
    
    VMA_DEBUG_LOG("vmaResizeAllocation");
    
    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordResizeAllocation(
            allocator->GetCurrentFrameIndex(),
            allocation,
            newSize);
    }
#endif
    
    return allocator->ResizeAllocation(allocation, newSize);
}

void vmaGetAllocationInfo(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VmaAllocationInfo* pAllocationInfo)
{
    VMA_ASSERT(allocator && allocation && pAllocationInfo);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordGetAllocationInfo(
            allocator->GetCurrentFrameIndex(),
            allocation);
    }
#endif

    allocator->GetAllocationInfo(allocation, pAllocationInfo);
}

VkBool32 vmaTouchAllocation(
    VmaAllocator allocator,
    VmaAllocation allocation)
{
    VMA_ASSERT(allocator && allocation);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordTouchAllocation(
            allocator->GetCurrentFrameIndex(),
            allocation);
    }
#endif

    return allocator->TouchAllocation(allocation);
}

void vmaSetAllocationUserData(
    VmaAllocator allocator,
    VmaAllocation allocation,
    void* pUserData)
{
    VMA_ASSERT(allocator && allocation);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    allocation->SetUserData(allocator, pUserData);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordSetAllocationUserData(
            allocator->GetCurrentFrameIndex(),
            allocation,
            pUserData);
    }
#endif
}

void vmaCreateLostAllocation(
    VmaAllocator allocator,
    VmaAllocation* pAllocation)
{
    VMA_ASSERT(allocator && pAllocation);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK;

    allocator->CreateLostAllocation(pAllocation);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordCreateLostAllocation(
            allocator->GetCurrentFrameIndex(),
            *pAllocation);
    }
#endif
}

VkResult vmaMapMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    void** ppData)
{
    VMA_ASSERT(allocator && allocation && ppData);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VkResult res = allocator->Map(allocation, ppData);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordMapMemory(
            allocator->GetCurrentFrameIndex(),
            allocation);
    }
#endif

    return res;
}

void vmaUnmapMemory(
    VmaAllocator allocator,
    VmaAllocation allocation)
{
    VMA_ASSERT(allocator && allocation);

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordUnmapMemory(
            allocator->GetCurrentFrameIndex(),
            allocation);
    }
#endif

    allocator->Unmap(allocation);
}

void vmaFlushAllocation(VmaAllocator allocator, VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size)
{
    VMA_ASSERT(allocator && allocation);

    VMA_DEBUG_LOG("vmaFlushAllocation");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    allocator->FlushOrInvalidateAllocation(allocation, offset, size, VMA_CACHE_FLUSH);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordFlushAllocation(
            allocator->GetCurrentFrameIndex(),
            allocation, offset, size);
    }
#endif
}

void vmaInvalidateAllocation(VmaAllocator allocator, VmaAllocation allocation, VkDeviceSize offset, VkDeviceSize size)
{
    VMA_ASSERT(allocator && allocation);

    VMA_DEBUG_LOG("vmaInvalidateAllocation");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    allocator->FlushOrInvalidateAllocation(allocation, offset, size, VMA_CACHE_INVALIDATE);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordInvalidateAllocation(
            allocator->GetCurrentFrameIndex(),
            allocation, offset, size);
    }
#endif
}

VkResult vmaCheckCorruption(VmaAllocator allocator, uint32_t memoryTypeBits)
{
    VMA_ASSERT(allocator);

    VMA_DEBUG_LOG("vmaCheckCorruption");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    return allocator->CheckCorruption(memoryTypeBits);
}

VkResult vmaDefragment(
    VmaAllocator allocator,
    VmaAllocation* pAllocations,
    size_t allocationCount,
    VkBool32* pAllocationsChanged,
    const VmaDefragmentationInfo *pDefragmentationInfo,
    VmaDefragmentationStats* pDefragmentationStats)
{
    // Deprecated interface, reimplemented using new one.

    VmaDefragmentationInfo2 info2 = {};
    info2.allocationCount = (uint32_t)allocationCount;
    info2.pAllocations = pAllocations;
    info2.pAllocationsChanged = pAllocationsChanged;
    if(pDefragmentationInfo != VMA_NULL)
    {
        info2.maxCpuAllocationsToMove = pDefragmentationInfo->maxAllocationsToMove;
        info2.maxCpuBytesToMove = pDefragmentationInfo->maxBytesToMove;
    }
    else
    {
        info2.maxCpuAllocationsToMove = UINT32_MAX;
        info2.maxCpuBytesToMove = VK_WHOLE_SIZE;
    }
    // info2.flags, maxGpuAllocationsToMove, maxGpuBytesToMove, commandBuffer deliberately left zero.

    VmaDefragmentationContext ctx;
    VkResult res = vmaDefragmentationBegin(allocator, &info2, pDefragmentationStats, &ctx);
    if(res == VK_NOT_READY)
    {
        res = vmaDefragmentationEnd( allocator, ctx);
    }
    return res;
}

VkResult vmaDefragmentationBegin(
    VmaAllocator allocator,
    const VmaDefragmentationInfo2* pInfo,
    VmaDefragmentationStats* pStats,
    VmaDefragmentationContext *pContext)
{
    VMA_ASSERT(allocator && pInfo && pContext);

    // Degenerate case: Nothing to defragment.
    if(pInfo->allocationCount == 0 && pInfo->poolCount == 0)
    {
        return VK_SUCCESS;
    }

    VMA_ASSERT(pInfo->allocationCount == 0 || pInfo->pAllocations != VMA_NULL);
    VMA_ASSERT(pInfo->poolCount == 0 || pInfo->pPools != VMA_NULL);
    VMA_HEAVY_ASSERT(VmaValidatePointerArray(pInfo->allocationCount, pInfo->pAllocations));
    VMA_HEAVY_ASSERT(VmaValidatePointerArray(pInfo->poolCount, pInfo->pPools));

    VMA_DEBUG_LOG("vmaDefragmentationBegin");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    VkResult res = allocator->DefragmentationBegin(*pInfo, pStats, pContext);

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordDefragmentationBegin(
            allocator->GetCurrentFrameIndex(), *pInfo, *pContext);
    }
#endif

    return res;
}

VkResult vmaDefragmentationEnd(
    VmaAllocator allocator,
    VmaDefragmentationContext context)
{
    VMA_ASSERT(allocator);

    VMA_DEBUG_LOG("vmaDefragmentationEnd");

    if(context != VK_NULL_HANDLE)
    {
        VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
        if(allocator->GetRecorder() != VMA_NULL)
        {
            allocator->GetRecorder()->RecordDefragmentationEnd(
                allocator->GetCurrentFrameIndex(), context);
        }
#endif

        return allocator->DefragmentationEnd(context);
    }
    else
    {
        return VK_SUCCESS;
    }
}

VkResult vmaBindBufferMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkBuffer buffer)
{
    VMA_ASSERT(allocator && allocation && buffer);

    VMA_DEBUG_LOG("vmaBindBufferMemory");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    return allocator->BindBufferMemory(allocation, buffer);
}

VkResult vmaBindImageMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkImage image)
{
    VMA_ASSERT(allocator && allocation && image);

    VMA_DEBUG_LOG("vmaBindImageMemory");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    return allocator->BindImageMemory(allocation, image);
}

VkResult vmaCreateBuffer(
    VmaAllocator allocator,
    const VkBufferCreateInfo* pBufferCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VkBuffer* pBuffer,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{
    VMA_ASSERT(allocator && pBufferCreateInfo && pAllocationCreateInfo && pBuffer && pAllocation);

    if(pBufferCreateInfo->size == 0)
    {
        return VK_ERROR_VALIDATION_FAILED_EXT;
    }
    
    VMA_DEBUG_LOG("vmaCreateBuffer");
    
    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    *pBuffer = VK_NULL_HANDLE;
    *pAllocation = VK_NULL_HANDLE;

    // 1. Create VkBuffer.
    VkResult res = (*allocator->GetVulkanFunctions().vkCreateBuffer)(
        allocator->m_hDevice,
        pBufferCreateInfo,
        allocator->GetAllocationCallbacks(),
        pBuffer);
    if(res >= 0)
    {
        // 2. vkGetBufferMemoryRequirements.
        VkMemoryRequirements vkMemReq = {};
        bool requiresDedicatedAllocation = false;
        bool prefersDedicatedAllocation  = false;
        allocator->GetBufferMemoryRequirements(*pBuffer, vkMemReq,
            requiresDedicatedAllocation, prefersDedicatedAllocation);

        // Make sure alignment requirements for specific buffer usages reported
        // in Physical Device Properties are included in alignment reported by memory requirements.
        if((pBufferCreateInfo->usage & VK_BUFFER_USAGE_UNIFORM_TEXEL_BUFFER_BIT) != 0)
        {
           VMA_ASSERT(vkMemReq.alignment %
              allocator->m_PhysicalDeviceProperties.limits.minTexelBufferOffsetAlignment == 0);
        }
        if((pBufferCreateInfo->usage & VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT) != 0)
        {
           VMA_ASSERT(vkMemReq.alignment %
              allocator->m_PhysicalDeviceProperties.limits.minUniformBufferOffsetAlignment == 0);
        }
        if((pBufferCreateInfo->usage & VK_BUFFER_USAGE_STORAGE_BUFFER_BIT) != 0)
        {
           VMA_ASSERT(vkMemReq.alignment %
              allocator->m_PhysicalDeviceProperties.limits.minStorageBufferOffsetAlignment == 0);
        }

        // 3. Allocate memory using allocator.
        res = allocator->AllocateMemory(
            vkMemReq,
            requiresDedicatedAllocation,
            prefersDedicatedAllocation,
            *pBuffer, // dedicatedBuffer
            VK_NULL_HANDLE, // dedicatedImage
            *pAllocationCreateInfo,
            VMA_SUBALLOCATION_TYPE_BUFFER,
            1, // allocationCount
            pAllocation);

#if VMA_RECORDING_ENABLED
        if(allocator->GetRecorder() != VMA_NULL)
        {
            allocator->GetRecorder()->RecordCreateBuffer(
                allocator->GetCurrentFrameIndex(),
                *pBufferCreateInfo,
                *pAllocationCreateInfo,
                *pAllocation);
        }
#endif

        if(res >= 0)
        {
            // 3. Bind buffer with memory.
            if((pAllocationCreateInfo->flags & VMA_ALLOCATION_CREATE_DONT_BIND_BIT) == 0)
            {
                res = allocator->BindBufferMemory(*pAllocation, *pBuffer);
            }
            if(res >= 0)
            {
                // All steps succeeded.
                #if VMA_STATS_STRING_ENABLED
                    (*pAllocation)->InitBufferImageUsage(pBufferCreateInfo->usage);
                #endif
                if(pAllocationInfo != VMA_NULL)
                {
                    allocator->GetAllocationInfo(*pAllocation, pAllocationInfo);
                }

                return VK_SUCCESS;
            }
            allocator->FreeMemory(
                1, // allocationCount
                pAllocation);
            *pAllocation = VK_NULL_HANDLE;
            (*allocator->GetVulkanFunctions().vkDestroyBuffer)(allocator->m_hDevice, *pBuffer, allocator->GetAllocationCallbacks());
            *pBuffer = VK_NULL_HANDLE;
            return res;
        }
        (*allocator->GetVulkanFunctions().vkDestroyBuffer)(allocator->m_hDevice, *pBuffer, allocator->GetAllocationCallbacks());
        *pBuffer = VK_NULL_HANDLE;
        return res;
    }
    return res;
}

void vmaDestroyBuffer(
    VmaAllocator allocator,
    VkBuffer buffer,
    VmaAllocation allocation)
{
    VMA_ASSERT(allocator);

    if(buffer == VK_NULL_HANDLE && allocation == VK_NULL_HANDLE)
    {
        return;
    }

    VMA_DEBUG_LOG("vmaDestroyBuffer");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordDestroyBuffer(
            allocator->GetCurrentFrameIndex(),
            allocation);
    }
#endif

    if(buffer != VK_NULL_HANDLE)
    {
        (*allocator->GetVulkanFunctions().vkDestroyBuffer)(allocator->m_hDevice, buffer, allocator->GetAllocationCallbacks());
    }

    if(allocation != VK_NULL_HANDLE)
    {
        allocator->FreeMemory(
            1, // allocationCount
            &allocation);
    }
}

VkResult vmaCreateImage(
    VmaAllocator allocator,
    const VkImageCreateInfo* pImageCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VkImage* pImage,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{
    VMA_ASSERT(allocator && pImageCreateInfo && pAllocationCreateInfo && pImage && pAllocation);

    if(pImageCreateInfo->extent.width == 0 ||
        pImageCreateInfo->extent.height == 0 ||
        pImageCreateInfo->extent.depth == 0 ||
        pImageCreateInfo->mipLevels == 0 ||
        pImageCreateInfo->arrayLayers == 0)
    {
        return VK_ERROR_VALIDATION_FAILED_EXT;
    }

    VMA_DEBUG_LOG("vmaCreateImage");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

    *pImage = VK_NULL_HANDLE;
    *pAllocation = VK_NULL_HANDLE;

    // 1. Create VkImage.
    VkResult res = (*allocator->GetVulkanFunctions().vkCreateImage)(
        allocator->m_hDevice,
        pImageCreateInfo,
        allocator->GetAllocationCallbacks(),
        pImage);
    if(res >= 0)
    {
        VmaSuballocationType suballocType = pImageCreateInfo->tiling == VK_IMAGE_TILING_OPTIMAL ?
            VMA_SUBALLOCATION_TYPE_IMAGE_OPTIMAL :
            VMA_SUBALLOCATION_TYPE_IMAGE_LINEAR;
        
        // 2. Allocate memory using allocator.
        VkMemoryRequirements vkMemReq = {};
        bool requiresDedicatedAllocation = false;
        bool prefersDedicatedAllocation  = false;
        allocator->GetImageMemoryRequirements(*pImage, vkMemReq,
            requiresDedicatedAllocation, prefersDedicatedAllocation);

        res = allocator->AllocateMemory(
            vkMemReq,
            requiresDedicatedAllocation,
            prefersDedicatedAllocation,
            VK_NULL_HANDLE, // dedicatedBuffer
            *pImage, // dedicatedImage
            *pAllocationCreateInfo,
            suballocType,
            1, // allocationCount
            pAllocation);

#if VMA_RECORDING_ENABLED
        if(allocator->GetRecorder() != VMA_NULL)
        {
            allocator->GetRecorder()->RecordCreateImage(
                allocator->GetCurrentFrameIndex(),
                *pImageCreateInfo,
                *pAllocationCreateInfo,
                *pAllocation);
        }
#endif

        if(res >= 0)
        {
            // 3. Bind image with memory.
            if((pAllocationCreateInfo->flags & VMA_ALLOCATION_CREATE_DONT_BIND_BIT) == 0)
            {
                res = allocator->BindImageMemory(*pAllocation, *pImage);
            }
            if(res >= 0)
            {
                // All steps succeeded.
                #if VMA_STATS_STRING_ENABLED
                    (*pAllocation)->InitBufferImageUsage(pImageCreateInfo->usage);
                #endif
                if(pAllocationInfo != VMA_NULL)
                {
                    allocator->GetAllocationInfo(*pAllocation, pAllocationInfo);
                }

                return VK_SUCCESS;
            }
            allocator->FreeMemory(
                1, // allocationCount
                pAllocation);
            *pAllocation = VK_NULL_HANDLE;
            (*allocator->GetVulkanFunctions().vkDestroyImage)(allocator->m_hDevice, *pImage, allocator->GetAllocationCallbacks());
            *pImage = VK_NULL_HANDLE;
            return res;
        }
        (*allocator->GetVulkanFunctions().vkDestroyImage)(allocator->m_hDevice, *pImage, allocator->GetAllocationCallbacks());
        *pImage = VK_NULL_HANDLE;
        return res;
    }
    return res;
}

void vmaDestroyImage(
    VmaAllocator allocator,
    VkImage image,
    VmaAllocation allocation)
{
    VMA_ASSERT(allocator);

    if(image == VK_NULL_HANDLE && allocation == VK_NULL_HANDLE)
    {
        return;
    }

    VMA_DEBUG_LOG("vmaDestroyImage");

    VMA_DEBUG_GLOBAL_MUTEX_LOCK

#if VMA_RECORDING_ENABLED
    if(allocator->GetRecorder() != VMA_NULL)
    {
        allocator->GetRecorder()->RecordDestroyImage(
            allocator->GetCurrentFrameIndex(),
            allocation);
    }
#endif

    if(image != VK_NULL_HANDLE)
    {
        (*allocator->GetVulkanFunctions().vkDestroyImage)(allocator->m_hDevice, image, allocator->GetAllocationCallbacks());
    }
    if(allocation != VK_NULL_HANDLE)
    {
        allocator->FreeMemory(
            1, // allocationCount
            &allocation);
    }
}

#endif // #ifdef VMA_IMPLEMENTATION