Files
CoopAllTheThings/common/include/coop/shared_memory.hpp
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Run clang-format (the repo's .clang-format: LLVM base, 120 cols, tabs,
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Also set SortIncludes: false in .clang-format. Windows include order is
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dinput.h; winsock2.h must precede windows.h), and the default
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break. Leaving order alone keeps the manual, correct grouping.
2026-07-12 11:52:53 +02:00

116 lines
2.7 KiB
C++

// Thin RAII wrapper over a Win32 file-mapping section used as the host<->hook
// IPC transport. Header-only so both modules share one implementation.
#pragma once
#include <string>
#include <utility>
#include <windows.h>
#include "coop/protocol.hpp"
namespace coop {
class SharedMemory {
public:
SharedMemory() = default;
SharedMemory(const SharedMemory&) = delete;
SharedMemory& operator=(const SharedMemory&) = delete;
SharedMemory(SharedMemory&& other) noexcept { *this = std::move(other); }
SharedMemory& operator=(SharedMemory&& other) noexcept
{
if (this != &other) {
reset();
mapping_ = std::exchange(other.mapping_, nullptr);
view_ = std::exchange(other.view_, nullptr);
size_ = std::exchange(other.size_, 0);
}
return *this;
}
~SharedMemory() { reset(); }
// Host side: create (or open if it already exists) the named section.
bool create(const std::wstring& name, std::size_t size)
{
reset();
mapping_ = CreateFileMappingW(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE, 0, static_cast<DWORD>(size),
name.c_str());
if (mapping_ == nullptr) {
return false;
}
return map(size);
}
// Hook side: open an existing section created by the host.
bool open(const std::wstring& name, std::size_t size)
{
reset();
mapping_ = OpenFileMappingW(FILE_MAP_ALL_ACCESS, FALSE, name.c_str());
if (mapping_ == nullptr) {
return false;
}
return map(size);
}
void reset()
{
if (view_ != nullptr) {
UnmapViewOfFile(view_);
view_ = nullptr;
}
if (mapping_ != nullptr) {
CloseHandle(mapping_);
mapping_ = nullptr;
}
size_ = 0;
}
[[nodiscard]] bool valid() const { return view_ != nullptr; }
template <typename T>
[[nodiscard]] T* as() const
{
return static_cast<T*>(view_);
}
[[nodiscard]] void* data() const { return view_; }
[[nodiscard]] std::size_t size() const { return size_; }
private:
bool map(std::size_t size)
{
view_ = MapViewOfFile(mapping_, FILE_MAP_ALL_ACCESS, 0, 0, size);
if (view_ == nullptr) {
CloseHandle(mapping_);
mapping_ = nullptr;
return false;
}
size_ = size;
return true;
}
HANDLE mapping_ = nullptr;
void* view_ = nullptr;
std::size_t size_ = 0;
};
// Build the per-pid section name both sides agree on.
inline std::wstring shared_memory_name(unsigned long target_pid)
{
return std::wstring(kSharedMemoryPrefix) + std::to_wstring(target_pid);
}
// Name of the Present-hook shared backbuffer texture (created by the hook with
// CreateSharedHandle, opened by the host with OpenSharedResourceByName).
inline std::wstring video_share_name(unsigned long target_pid)
{
return std::wstring(kVideoSharePrefix) + std::to_wstring(target_pid);
}
} // namespace coop