replaced common code with dolphin common

src/common/src/mem_arena.h

@@ -0,0 +1,58 @@
+// Copyright 2013 Dolphin Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+
+#ifndef _MEMARENA_H_
+#define _MEMARENA_H_
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+#include "common.h"
+
+// This class lets you create a block of anonymous RAM, and then arbitrarily map views into it.
+// Multiple views can mirror the same section of the block, which makes it very convenient for emulating
+// memory mirrors.
+
+class MemArena
+{
+public:
+	void GrabLowMemSpace(size_t size);
+	void ReleaseSpace();
+	void *CreateView(s64 offset, size_t size, void *base = nullptr);
+	void ReleaseView(void *view, size_t size);
+
+	// This only finds 1 GB in 32-bit
+	static u8 *Find4GBBase();
+private:
+
+#ifdef _WIN32
+	HANDLE hMemoryMapping;
+#else
+	int fd;
+#endif
+};
+
+enum {
+	MV_MIRROR_PREVIOUS = 1,
+	MV_FAKE_VMEM = 2,
+	MV_WII_ONLY = 4,
+};
+
+struct MemoryView
+{
+	u8 **out_ptr_low;
+	u8 **out_ptr;
+	u32 virtual_address;
+	u32 size;
+	u32 flags;
+};
+
+// Uses a memory arena to set up an emulator-friendly memory map according to
+// a passed-in list of MemoryView structures.
+u8 *MemoryMap_Setup(const MemoryView *views, int num_views, u32 flags, MemArena *arena);
+void MemoryMap_Shutdown(const MemoryView *views, int num_views, u32 flags, MemArena *arena);
+
+#endif // _MEMARENA_H_