suyu/src/common/fiber.h

57 lines
1.7 KiB
C++

// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-FileCopyrightText: Copyright 2024 suyu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <functional>
#include <memory>
#include "common/minicoro.h"
namespace Common {
/**
* Fiber class
* a fiber is a userspace thread with it's own context. They can be used to
* implement coroutines, emulated threading systems and certain asynchronous
* patterns.
*
* This class implements fibers at a low level, thus allowing greater freedom
* to implement such patterns. This fiber class is 'threadsafe' only one fiber
* can be running at a time and threads will be locked while trying to yield to
* a running fiber until it yields. WARNING exchanging two running fibers between
* threads will cause a deadlock. In order to prevent a deadlock, each thread should
* have an intermediary fiber, you switch to the intermediary fiber of the current
* thread and then from it switch to the expected fiber. This way you can exchange
* 2 fibers within 2 different threads.
*/
class Fiber {
public:
Fiber(std::function<void()>&& entry_point_func);
~Fiber();
Fiber(const Fiber&) = delete;
Fiber& operator=(const Fiber&) = delete;
Fiber(Fiber&&) = default;
Fiber& operator=(Fiber&&) = default;
static void YieldTo(std::weak_ptr<Fiber> weak_from, Fiber& to);
[[nodiscard]] static std::shared_ptr<Fiber> ThreadToFiber();
/// Only call from main thread's fiber
void Exit();
private:
Fiber();
void DestroyPre();
void DestroyWorkFiber();
void DestroyThreadFiber();
struct FiberImpl;
std::unique_ptr<FiberImpl> impl;
};
} // namespace Common