dolphin/Source/Core/Common/MemArena.h

// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.

#pragma once

#include <cstddef>

#ifdef _WIN32
#include <windows.h>
#endif

#include "Common/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);