citra/src/common/mem_arena.h

// Copyright (C) 2003 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

#pragma once

#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 convient for emulating
// memory mirrors.

class MemArena
{
public:
    void GrabLowMemSpace(size_t size);
    void ReleaseSpace();
    void *CreateView(s64 offset, size_t size, void *base = 0);
    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,
    MV_IS_PRIMARY_RAM = 0x100,
    MV_IS_EXTRA1_RAM = 0x200,
    MV_IS_EXTRA2_RAM = 0x400,
};

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);