dolphin/Source/Core/Common/MemArena.cpp

312 lines
7.3 KiB
C++

// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#include <cstddef>
#include <cstdlib>
#include <set>
#include <string>
#include "Common/Common.h"
#include "Common/MemArena.h"
#include "Common/StringUtil.h"
#ifdef _WIN32
#include <windows.h>
#else
#include <cerrno>
#include <cstring>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#ifdef ANDROID
#include <sys/ioctl.h>
#include <linux/ashmem.h>
#endif
#endif
#ifdef ANDROID
#define ASHMEM_DEVICE "/dev/ashmem"
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::GrabLowMemSpace(size_t size)
{
#ifdef _WIN32
hMemoryMapping = CreateFileMapping(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE, 0, (DWORD)(size), nullptr);
#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::ReleaseSpace()
{
#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::Find4GBBase()
{
#if _ARCH_64
#ifdef _WIN32
// 64 bit
u8* base = (u8*)VirtualAlloc(0, 0xE1000000, MEM_RESERVE, PAGE_READWRITE);
VirtualFree(base, 0, MEM_RELEASE);
return base;
#else
// Very precarious - mmap cannot return an error when trying to map already used pages.
// This makes the Windows approach above unusable on Linux, so we will simply pray...
return reinterpret_cast<u8*>(0x2300000000ULL);
#endif
#else
// 32 bit
#ifdef _WIN32
// The highest thing in any 1GB section of memory space is the locked cache. We only need to fit it.
u8* base = (u8*)VirtualAlloc(0, 0x31000000, MEM_RESERVE, PAGE_READWRITE);
if (base) {
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
const u32 MemSize = 0x31000000;
void* base = mmap(0, MemSize, PROT_NONE, flags, -1, 0);
if (base == MAP_FAILED) {
PanicAlert("Failed to map 1 GB of memory space: %s", strerror(errno));
return 0;
}
munmap(base, MemSize);
return static_cast<u8*>(base);
#endif
#endif
}
// yeah, this could also be done in like two bitwise ops...
#define SKIP(a_flags, b_flags) \
if (!(a_flags & MV_WII_ONLY) && (b_flags & MV_WII_ONLY)) \
continue; \
if (!(a_flags & MV_FAKE_VMEM) && (b_flags & MV_FAKE_VMEM)) \
continue; \
static bool Memory_TryBase(u8 *base, const MemoryView *views, int num_views, u32 flags, MemArena *arena) {
// OK, we know where to find free space. Now grab it!
// We just mimic the popular BAT setup.
u32 position = 0;
u32 last_position = 0;
// Zero all the pointers to be sure.
for (int i = 0; i < num_views; i++)
{
if (views[i].out_ptr_low)
*views[i].out_ptr_low = nullptr;
if (views[i].out_ptr)
*views[i].out_ptr = nullptr;
}
int i;
for (i = 0; i < num_views; i++)
{
SKIP(flags, views[i].flags);
if (views[i].flags & MV_MIRROR_PREVIOUS) {
position = last_position;
} else {
*(views[i].out_ptr_low) = (u8*)arena->CreateView(position, views[i].size);
if (!*views[i].out_ptr_low)
goto bail;
}
#if _ARCH_64
*views[i].out_ptr = (u8*)arena->CreateView(
position, views[i].size, base + views[i].virtual_address);
#else
if (views[i].flags & MV_MIRROR_PREVIOUS) {
// No need to create multiple identical views.
*views[i].out_ptr = *views[i - 1].out_ptr;
} else {
*views[i].out_ptr = (u8*)arena->CreateView(
position, views[i].size, base + (views[i].virtual_address & 0x3FFFFFFF));
if (!*views[i].out_ptr)
goto bail;
}
#endif
last_position = position;
position += views[i].size;
}
return true;
bail:
// Argh! ERROR! Free what we grabbed so far so we can try again.
MemoryMap_Shutdown(views, i+1, flags, arena);
return false;
}
u8 *MemoryMap_Setup(const MemoryView *views, int num_views, u32 flags, MemArena *arena)
{
u32 total_mem = 0;
int base_attempts = 0;
for (int i = 0; i < num_views; i++)
{
SKIP(flags, views[i].flags);
if ((views[i].flags & MV_MIRROR_PREVIOUS) == 0)
total_mem += views[i].size;
}
// Grab some pagefile backed memory out of the void ...
arena->GrabLowMemSpace(total_mem);
// Now, create views in high memory where there's plenty of space.
#if _ARCH_64
u8 *base = MemArena::Find4GBBase();
// This really shouldn't fail - in 64-bit, there will always be enough
// address space.
if (!Memory_TryBase(base, views, num_views, flags, arena))
{
PanicAlert("MemoryMap_Setup: Failed finding a memory base.");
exit(0);
return nullptr;
}
#else
#ifdef _WIN32
// Try a whole range of possible bases. Return once we got a valid one.
u32 max_base_addr = 0x7FFF0000 - 0x31000000;
u8 *base = nullptr;
for (u32 base_addr = 0x40000; base_addr < max_base_addr; base_addr += 0x40000)
{
base_attempts++;
base = (u8 *)base_addr;
if (Memory_TryBase(base, views, num_views, flags, arena))
{
INFO_LOG(MEMMAP, "Found valid memory base at %p after %i tries.", base, base_attempts);
base_attempts = 0;
break;
}
}
#else
// Linux32 is fine with the x64 method, although limited to 32-bit with no automirrors.
u8 *base = MemArena::Find4GBBase();
if (!Memory_TryBase(base, views, num_views, flags, arena))
{
PanicAlert("MemoryMap_Setup: Failed finding a memory base.");
exit(0);
return 0;
}
#endif
#endif
if (base_attempts)
PanicAlert("No possible memory base pointer found!");
return base;
}
void MemoryMap_Shutdown(const MemoryView *views, int num_views, u32 flags, MemArena *arena)
{
std::set<void*> freeset;
for (int i = 0; i < num_views; i++)
{
const MemoryView* view = &views[i];
u8** outptrs[2] = {view->out_ptr_low, view->out_ptr};
for (auto outptr : outptrs)
{
if (outptr && *outptr && !freeset.count(*outptr))
{
arena->ReleaseView(*outptr, view->size);
freeset.insert(*outptr);
*outptr = nullptr;
}
}
}
}