yuzu/src/common/fiber.cpp
2020-06-18 16:29:19 -04:00

158 lines
4.5 KiB
C++

// Copyright 2020 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "common/assert.h"
#include "common/fiber.h"
#ifdef _MSC_VER
#include <windows.h>
#else
#include <boost/context/detail/fcontext.hpp>
#endif
namespace Common {
#ifdef _MSC_VER
struct Fiber::FiberImpl {
LPVOID handle = nullptr;
};
void Fiber::start() {
ASSERT(previous_fiber != nullptr);
previous_fiber->guard.unlock();
previous_fiber.reset();
entry_point(start_parameter);
UNREACHABLE();
}
void __stdcall Fiber::FiberStartFunc(void* fiber_parameter)
{
auto fiber = static_cast<Fiber *>(fiber_parameter);
fiber->start();
}
Fiber::Fiber(std::function<void(void*)>&& entry_point_func, void* start_parameter)
: guard{}, entry_point{std::move(entry_point_func)}, start_parameter{start_parameter}, previous_fiber{} {
impl = std::make_unique<FiberImpl>();
impl->handle = CreateFiber(0, &FiberStartFunc, this);
}
Fiber::Fiber() : guard{}, entry_point{}, start_parameter{}, previous_fiber{} {
impl = std::make_unique<FiberImpl>();
}
Fiber::~Fiber() {
// Make sure the Fiber is not being used
bool locked = guard.try_lock();
ASSERT_MSG(locked, "Destroying a fiber that's still running");
if (locked) {
guard.unlock();
}
DeleteFiber(impl->handle);
}
void Fiber::Exit() {
ASSERT_MSG(is_thread_fiber, "Exitting non main thread fiber");
if (!is_thread_fiber) {
return;
}
ConvertFiberToThread();
guard.unlock();
}
void Fiber::YieldTo(std::shared_ptr<Fiber> from, std::shared_ptr<Fiber> to) {
ASSERT_MSG(from != nullptr, "Yielding fiber is null!");
ASSERT_MSG(to != nullptr, "Next fiber is null!");
to->guard.lock();
to->previous_fiber = from;
SwitchToFiber(to->impl->handle);
auto previous_fiber = from->previous_fiber;
ASSERT(previous_fiber != nullptr);
previous_fiber->guard.unlock();
previous_fiber.reset();
}
std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
fiber->guard.lock();
fiber->impl->handle = ConvertThreadToFiber(NULL);
fiber->is_thread_fiber = true;
return fiber;
}
#else
constexpr std::size_t default_stack_size = 1024 * 1024 * 4; // 4MB
struct alignas(64) Fiber::FiberImpl {
std::array<u8, default_stack_size> stack;
boost::context::detail::fcontext_t context;
};
void Fiber::start(boost::context::detail::transfer_t& transfer) {
ASSERT(previous_fiber != nullptr);
previous_fiber->impl->context = transfer.fctx;
previous_fiber->guard.unlock();
previous_fiber.reset();
entry_point(start_parameter);
UNREACHABLE();
}
void Fiber::FiberStartFunc(boost::context::detail::transfer_t transfer)
{
auto fiber = static_cast<Fiber *>(transfer.data);
fiber->start(transfer);
}
Fiber::Fiber(std::function<void(void*)>&& entry_point_func, void* start_parameter)
: guard{}, entry_point{std::move(entry_point_func)}, start_parameter{start_parameter}, previous_fiber{} {
impl = std::make_unique<FiberImpl>();
impl->context = boost::context::detail::make_fcontext(impl->stack.data(), impl->stack.size(),
FiberStartFunc);
}
Fiber::Fiber() : guard{}, entry_point{}, start_parameter{}, previous_fiber{} {
impl = std::make_unique<FiberImpl>();
}
Fiber::~Fiber() {
// Make sure the Fiber is not being used
bool locked = guard.try_lock();
ASSERT_MSG(locked, "Destroying a fiber that's still running");
if (locked) {
guard.unlock();
}
}
void Fiber::Exit() {
ASSERT_MSG(is_thread_fiber, "Exitting non main thread fiber");
if (!is_thread_fiber) {
return;
}
guard.unlock();
}
void Fiber::YieldTo(std::shared_ptr<Fiber> from, std::shared_ptr<Fiber> to) {
ASSERT_MSG(from != nullptr, "Yielding fiber is null!");
ASSERT_MSG(to != nullptr, "Next fiber is null!");
to->guard.lock();
to->previous_fiber = from;
auto transfer = boost::context::detail::jump_fcontext(to->impl->context, nullptr);
auto previous_fiber = from->previous_fiber;
ASSERT(previous_fiber != nullptr);
previous_fiber->impl->context = transfer.fctx;
previous_fiber->guard.unlock();
previous_fiber.reset();
}
std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
fiber->guard.lock();
fiber->is_thread_fiber = true;
return fiber;
}
#endif
} // namespace Common