dolphin/Source/Core/Common/MemArena.cpp
Dane Z. Bush 4dfe6c0875 MemArena: Name shared memory handle
Assign a name to the CreateFileMapping handle on Win32 so third party
applications can read from Dolphin's memory and integrate with the
current emulation.

Built and tested, multiple sessions are still possible without
collisions.
2017-10-11 16:35:32 +02:00

163 lines
3.6 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include <cstddef>
#include <cstdlib>
#include <set>
#include <string>
#include "Common/CommonFuncs.h"
#include "Common/CommonTypes.h"
#include "Common/Logging/Log.h"
#include "Common/MemArena.h"
#include "Common/MsgHandler.h"
#include "Common/StringUtil.h"
#ifdef _WIN32
#include <windows.h>
#else
#include <cerrno>
#include <cstring>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#ifdef ANDROID
#include <linux/ashmem.h>
#include <sys/ioctl.h>
#endif
#endif
#ifdef ANDROID
#define ASHMEM_DEVICE "/dev/ashmem"
static int AshmemCreateFileMapping(const char* name, size_t size)
{
int fd, ret;
fd = open(ASHMEM_DEVICE, O_RDWR);
if (fd < 0)
return fd;
// We don't really care if we can't set the name, it is optional
ioctl(fd, ASHMEM_SET_NAME, name);
ret = ioctl(fd, ASHMEM_SET_SIZE, size);
if (ret < 0)
{
close(fd);
NOTICE_LOG(MEMMAP, "Ashmem returned error: 0x%08x", ret);
return ret;
}
return fd;
}
#endif
void MemArena::GrabSHMSegment(size_t size)
{
#ifdef _WIN32
hMemoryMapping = CreateFileMapping(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE, 0,
static_cast<DWORD>(size), L"Dolphin-emu");
#elif defined(ANDROID)
fd = AshmemCreateFileMapping("Dolphin-emu", size);
if (fd < 0)
{
NOTICE_LOG(MEMMAP, "Ashmem allocation failed");
return;
}
#else
for (int i = 0; i < 10000; i++)
{
std::string file_name = StringFromFormat("/dolphinmem.%d", i);
fd = shm_open(file_name.c_str(), O_RDWR | O_CREAT | O_EXCL, 0600);
if (fd != -1)
{
shm_unlink(file_name.c_str());
break;
}
else if (errno != EEXIST)
{
ERROR_LOG(MEMMAP, "shm_open failed: %s", strerror(errno));
return;
}
}
if (ftruncate(fd, size) < 0)
ERROR_LOG(MEMMAP, "Failed to allocate low memory space");
#endif
}
void MemArena::ReleaseSHMSegment()
{
#ifdef _WIN32
CloseHandle(hMemoryMapping);
hMemoryMapping = 0;
#else
close(fd);
#endif
}
void* MemArena::CreateView(s64 offset, size_t size, void* base)
{
#ifdef _WIN32
return MapViewOfFileEx(hMemoryMapping, FILE_MAP_ALL_ACCESS, 0, (DWORD)((u64)offset), size, base);
#else
void* retval = mmap(base, size, PROT_READ | PROT_WRITE,
MAP_SHARED | ((base == nullptr) ? 0 : MAP_FIXED), fd, offset);
if (retval == MAP_FAILED)
{
NOTICE_LOG(MEMMAP, "mmap failed");
return nullptr;
}
else
{
return retval;
}
#endif
}
void MemArena::ReleaseView(void* view, size_t size)
{
#ifdef _WIN32
UnmapViewOfFile(view);
#else
munmap(view, size);
#endif
}
u8* MemArena::FindMemoryBase()
{
#if _ARCH_32
const size_t memory_size = 0x31000000;
#else
const size_t memory_size = 0x400000000;
#endif
#ifdef _WIN32
u8* base = static_cast<u8*>(VirtualAlloc(nullptr, memory_size, MEM_RESERVE, PAGE_READWRITE));
if (!base)
{
PanicAlert("Failed to map enough memory space: %s", GetLastErrorString().c_str());
return nullptr;
}
VirtualFree(base, 0, MEM_RELEASE);
return base;
#else
#ifdef ANDROID
// Android 4.3 changed how mmap works.
// if we map it private and then munmap it, we can't use the base returned.
// This may be due to changes in them support a full SELinux implementation.
const int flags = MAP_ANON | MAP_SHARED;
#else
const int flags = MAP_ANON | MAP_PRIVATE;
#endif
void* base = mmap(nullptr, memory_size, PROT_NONE, flags, -1, 0);
if (base == MAP_FAILED)
{
PanicAlert("Failed to map enough memory space: %s", LastStrerrorString().c_str());
return nullptr;
}
munmap(base, memory_size);
return static_cast<u8*>(base);
#endif
}