Panda3DS/third_party/pcsx2/WinHostSys.cpp
2024-11-28 23:24:32 +02:00

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8.8 KiB
C++

// SPDX-FileCopyrightText: 2002-2024 PCSX2 Dev Team
// SPDX-License-Identifier: GPL-3.0+
#include <pcsx2/HostSys.h>
#include <mutex>
#include "align.hpp"
#include "fmt/core.h"
#include "fmt/format.h"
#include "helpers.hpp"
static DWORD ConvertToWinApi(const PageProtectionMode& mode) {
DWORD winmode = PAGE_NOACCESS;
// Windows has some really bizarre memory protection enumeration that uses bitwise
// numbering (like flags) but is in fact not a flag value. *Someone* from the early
// microsoft days wasn't a very good coder, me thinks. --air
if (mode.CanExecute()) {
winmode = mode.CanWrite() ? PAGE_EXECUTE_READWRITE : PAGE_EXECUTE_READ;
} else if (mode.CanRead()) {
winmode = mode.CanWrite() ? PAGE_READWRITE : PAGE_READONLY;
}
return winmode;
}
void* HostSys::Mmap(void* base, size_t size, const PageProtectionMode& mode) {
if (mode.IsNone()) return nullptr;
return VirtualAlloc(base, size, MEM_RESERVE | MEM_COMMIT, ConvertToWinApi(mode));
}
void HostSys::Munmap(void* base, size_t size) {
if (!base) return;
VirtualFree((void*)base, 0, MEM_RELEASE);
}
void HostSys::MemProtect(void* baseaddr, size_t size, const PageProtectionMode& mode) {
pxAssert((size & (__pagesize - 1)) == 0);
DWORD OldProtect; // enjoy my uselessness, yo!
if (!VirtualProtect(baseaddr, size, ConvertToWinApi(mode), &OldProtect)) pxFail("VirtualProtect() failed");
}
std::string HostSys::GetFileMappingName(const char* prefix) {
const unsigned pid = GetCurrentProcessId();
return fmt::format("{}_{}", prefix, pid);
}
void* HostSys::CreateSharedMemory(const char* name, size_t size) {
return static_cast<void*>(CreateFileMappingW(
INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, static_cast<DWORD>(size >> 32), static_cast<DWORD>(size),
StringUtil::UTF8StringToWideString(name).c_str()
));
}
void HostSys::DestroySharedMemory(void* ptr) { CloseHandle(static_cast<HANDLE>(ptr)); }
void* HostSys::MapSharedMemory(void* handle, size_t offset, void* baseaddr, size_t size, const PageProtectionMode& mode) {
void* ret = MapViewOfFileEx(
static_cast<HANDLE>(handle), FILE_MAP_READ | FILE_MAP_WRITE, static_cast<DWORD>(offset >> 32), static_cast<DWORD>(offset), size, baseaddr
);
if (!ret) return nullptr;
const DWORD prot = ConvertToWinApi(mode);
if (prot != PAGE_READWRITE) {
DWORD old_prot;
if (!VirtualProtect(ret, size, prot, &old_prot)) pxFail("Failed to protect memory mapping");
}
return ret;
}
void HostSys::UnmapSharedMemory(void* baseaddr, size_t size) {
if (!UnmapViewOfFile(baseaddr)) pxFail("Failed to unmap shared memory");
}
size_t HostSys::GetRuntimePageSize() {
SYSTEM_INFO si = {};
GetSystemInfo(&si);
return si.dwPageSize;
}
SharedMemoryMappingArea::SharedMemoryMappingArea(u8* base_ptr, size_t size, size_t num_pages)
: m_base_ptr(base_ptr), m_size(size), m_num_pages(num_pages) {
m_placeholder_ranges.emplace(0, size);
}
SharedMemoryMappingArea::~SharedMemoryMappingArea() {
pxAssertRel(m_num_mappings == 0, "No mappings left");
// hopefully this will be okay, and we don't need to coalesce all the placeholders...
if (!VirtualFreeEx(GetCurrentProcess(), m_base_ptr, 0, MEM_RELEASE)) pxFailRel("Failed to release shared memory area");
}
SharedMemoryMappingArea::PlaceholderMap::iterator SharedMemoryMappingArea::FindPlaceholder(size_t offset) {
if (m_placeholder_ranges.empty()) return m_placeholder_ranges.end();
// this will give us an iterator equal or after page
auto it = m_placeholder_ranges.lower_bound(offset);
if (it == m_placeholder_ranges.end()) {
// check the last page
it = (++m_placeholder_ranges.rbegin()).base();
}
// it's the one we found?
if (offset >= it->first && offset < it->second) return it;
// otherwise try the one before
if (it == m_placeholder_ranges.begin()) return m_placeholder_ranges.end();
--it;
if (offset >= it->first && offset < it->second)
return it;
else
return m_placeholder_ranges.end();
}
std::unique_ptr<SharedMemoryMappingArea> SharedMemoryMappingArea::Create(size_t size) {
pxAssertRel(Common::IsAlignedPow2(size, __pagesize), "Size is page aligned");
void* alloc = VirtualAlloc2(GetCurrentProcess(), nullptr, size, MEM_RESERVE | MEM_RESERVE_PLACEHOLDER, PAGE_NOACCESS, nullptr, 0);
if (!alloc) return nullptr;
return std::unique_ptr<SharedMemoryMappingArea>(new SharedMemoryMappingArea(static_cast<u8*>(alloc), size, size / __pagesize));
}
u8* SharedMemoryMappingArea::Map(void* file_handle, size_t file_offset, void* map_base, size_t map_size, const PageProtectionMode& mode) {
pxAssert(static_cast<u8*>(map_base) >= m_base_ptr && static_cast<u8*>(map_base) < (m_base_ptr + m_size));
const size_t map_offset = static_cast<u8*>(map_base) - m_base_ptr;
pxAssert(Common::IsAlignedPow2(map_offset, __pagesize));
pxAssert(Common::IsAlignedPow2(map_size, __pagesize));
// should be a placeholder. unless there's some other mapping we didn't free.
PlaceholderMap::iterator phit = FindPlaceholder(map_offset);
pxAssertMsg(phit != m_placeholder_ranges.end(), "Page we're mapping is a placeholder");
pxAssertMsg(map_offset >= phit->first && map_offset < phit->second, "Page is in returned placeholder range");
pxAssertMsg((map_offset + map_size) <= phit->second, "Page range is in returned placeholder range");
// do we need to split to the left? (i.e. is there a placeholder before this range)
const size_t old_ph_end = phit->second;
if (map_offset != phit->first) {
phit->second = map_offset;
// split it (i.e. left..start and start..end are now separated)
if (!VirtualFreeEx(GetCurrentProcess(), OffsetPointer(phit->first), (map_offset - phit->first), MEM_RELEASE | MEM_PRESERVE_PLACEHOLDER)) {
pxFailRel("Failed to left split placeholder for map");
}
} else {
// start of the placeholder is getting used, we'll split it right below if there's anything left over
m_placeholder_ranges.erase(phit);
}
// do we need to split to the right? (i.e. is there a placeholder after this range)
if ((map_offset + map_size) != old_ph_end) {
// split out end..ph_end
m_placeholder_ranges.emplace(map_offset + map_size, old_ph_end);
if (!VirtualFreeEx(GetCurrentProcess(), OffsetPointer(map_offset), map_size, MEM_RELEASE | MEM_PRESERVE_PLACEHOLDER)) {
pxFailRel("Failed to right split placeholder for map");
}
}
// actually do the mapping, replacing the placeholder on the range
if (!MapViewOfFile3(
static_cast<HANDLE>(file_handle), GetCurrentProcess(), map_base, file_offset, map_size, MEM_REPLACE_PLACEHOLDER, PAGE_READWRITE, nullptr,
0
)) {
Console.Error("(SharedMemoryMappingArea) MapViewOfFile3() failed: %u", GetLastError());
return nullptr;
}
const DWORD prot = ConvertToWinApi(mode);
if (prot != PAGE_READWRITE) {
DWORD old_prot;
if (!VirtualProtect(map_base, map_size, prot, &old_prot)) pxFail("Failed to protect memory mapping");
}
m_num_mappings++;
return static_cast<u8*>(map_base);
}
bool SharedMemoryMappingArea::Unmap(void* map_base, size_t map_size) {
pxAssert(static_cast<u8*>(map_base) >= m_base_ptr && static_cast<u8*>(map_base) < (m_base_ptr + m_size));
const size_t map_offset = static_cast<u8*>(map_base) - m_base_ptr;
pxAssert(Common::IsAlignedPow2(map_offset, __pagesize));
pxAssert(Common::IsAlignedPow2(map_size, __pagesize));
// unmap the specified range
if (!UnmapViewOfFile2(GetCurrentProcess(), map_base, MEM_PRESERVE_PLACEHOLDER)) {
Console.Error("(SharedMemoryMappingArea) UnmapViewOfFile2() failed: %u", GetLastError());
return false;
}
// can we coalesce to the left?
PlaceholderMap::iterator left_it = (map_offset > 0) ? FindPlaceholder(map_offset - 1) : m_placeholder_ranges.end();
if (left_it != m_placeholder_ranges.end()) {
// the left placeholder should end at our start
pxAssert(map_offset == left_it->second);
left_it->second = map_offset + map_size;
// combine placeholders before and the range we're unmapping, i.e. to the left
if (!VirtualFreeEx(
GetCurrentProcess(), OffsetPointer(left_it->first), left_it->second - left_it->first, MEM_RELEASE | MEM_COALESCE_PLACEHOLDERS
)) {
pxFail("Failed to coalesce placeholders left for unmap");
}
} else {
// this is a new placeholder
left_it = m_placeholder_ranges.emplace(map_offset, map_offset + map_size).first;
}
// can we coalesce to the right?
PlaceholderMap::iterator right_it = ((map_offset + map_size) < m_size) ? FindPlaceholder(map_offset + map_size) : m_placeholder_ranges.end();
if (right_it != m_placeholder_ranges.end()) {
// should start at our end
pxAssert(right_it->first == (map_offset + map_size));
left_it->second = right_it->second;
m_placeholder_ranges.erase(right_it);
// combine our placeholder and the next, i.e. to the right
if (!VirtualFreeEx(
GetCurrentProcess(), OffsetPointer(left_it->first), left_it->second - left_it->first, MEM_RELEASE | MEM_COALESCE_PLACEHOLDERS
)) {
pxFail("Failed to coalescae placeholders right for unmap");
}
}
m_num_mappings--;
return true;
}