// SPDX-FileCopyrightText: 2022 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
//
// TODO: remove this file when jthread is supported by all compilation targets
//
#pragma once
#include <version>
#ifdef __cpp_lib_jthread
#include <stop_token>
#include <thread>
namespace Common {
template <typename Condvar, typename Lock, typename Pred>
void CondvarWait(Condvar& cv, Lock& lock, std::stop_token token, Pred&& pred) {
cv.wait(lock, token, std::move(pred));
}
} // namespace Common
#else
#include <atomic>
#include <functional>
#include <list>
#include <memory>
#include <mutex>
#include <optional>
#include <thread>
#include <type_traits>
namespace std {
namespace polyfill {
using stop_state_callbacks = list<function<void()>>;
class stop_state {
public:
stop_state() = default;
~stop_state() = default;
bool request_stop() {
stop_state_callbacks callbacks;
{
scoped_lock lk{m_lock};
if (m_stop_requested.load()) {
// Already set, nothing to do
return false;
}
// Set as requested
m_stop_requested = true;
// Copy callback list
callbacks = m_callbacks;
}
for (auto callback : callbacks) {
callback();
}
return true;
}
bool stop_requested() const {
return m_stop_requested.load();
}
stop_state_callbacks::const_iterator insert_callback(function<void()> f) {
stop_state_callbacks::const_iterator ret{};
bool should_run{};
{
scoped_lock lk{m_lock};
should_run = m_stop_requested.load();
m_callbacks.push_front(f);
ret = m_callbacks.begin();
}
if (should_run) {
f();
}
return ret;
}
void remove_callback(stop_state_callbacks::const_iterator it) {
scoped_lock lk{m_lock};
m_callbacks.erase(it);
}
private:
mutex m_lock;
atomic<bool> m_stop_requested;
stop_state_callbacks m_callbacks;
};
} // namespace polyfill
class stop_token;
class stop_source;
struct nostopstate_t {
explicit nostopstate_t() = default;
};
inline constexpr nostopstate_t nostopstate{};
template <class Callback>
class stop_callback;
class stop_token {
public:
stop_token() noexcept = default;
stop_token(const stop_token&) noexcept = default;
stop_token(stop_token&&) noexcept = default;
stop_token& operator=(const stop_token&) noexcept = default;
stop_token& operator=(stop_token&&) noexcept = default;
~stop_token() = default;
void swap(stop_token& other) noexcept {
m_stop_state.swap(other.m_stop_state);
}
[[nodiscard]] bool stop_requested() const noexcept {
return m_stop_state && m_stop_state->stop_requested();
}
[[nodiscard]] bool stop_possible() const noexcept {
return m_stop_state != nullptr;
}
private:
friend class stop_source;
template <typename Callback>
friend class stop_callback;
stop_token(shared_ptr<polyfill::stop_state> stop_state) : m_stop_state(move(stop_state)) {}
private:
shared_ptr<polyfill::stop_state> m_stop_state;
};
class stop_source {
public:
stop_source() : m_stop_state(make_shared<polyfill::stop_state>()) {}
explicit stop_source(nostopstate_t) noexcept {}
stop_source(const stop_source&) noexcept = default;
stop_source(stop_source&&) noexcept = default;
stop_source& operator=(const stop_source&) noexcept = default;
stop_source& operator=(stop_source&&) noexcept = default;
~stop_source() = default;
void swap(stop_source& other) noexcept {
m_stop_state.swap(other.m_stop_state);
}
[[nodiscard]] stop_token get_token() const noexcept {
return stop_token(m_stop_state);
}
[[nodiscard]] bool stop_possible() const noexcept {
return m_stop_state != nullptr;
}
[[nodiscard]] bool stop_requested() const noexcept {
return m_stop_state && m_stop_state->stop_requested();
}
bool request_stop() noexcept {
return m_stop_state && m_stop_state->request_stop();
}
private:
friend class jthread;
explicit stop_source(shared_ptr<polyfill::stop_state> stop_state)
: m_stop_state(move(stop_state)) {}
private:
shared_ptr<polyfill::stop_state> m_stop_state;
};
template <typename Callback>
class stop_callback {
static_assert(is_nothrow_destructible_v<Callback>);
static_assert(is_invocable_v<Callback>);
public:
using callback_type = Callback;
template <typename C>
requires constructible_from<Callback, C>
explicit stop_callback(const stop_token& st,
C&& cb) noexcept(is_nothrow_constructible_v<Callback, C>)
: m_stop_state(st.m_stop_state) {
if (m_stop_state) {
m_callback = m_stop_state->insert_callback(move(cb));
}
}
template <typename C>
requires constructible_from<Callback, C>
explicit stop_callback(stop_token&& st,
C&& cb) noexcept(is_nothrow_constructible_v<Callback, C>)
: m_stop_state(move(st.m_stop_state)) {
if (m_stop_state) {
m_callback = m_stop_state->insert_callback(move(cb));
}
}
~stop_callback() {
if (m_stop_state && m_callback) {
m_stop_state->remove_callback(*m_callback);
}
}
stop_callback(const stop_callback&) = delete;
stop_callback(stop_callback&&) = delete;
stop_callback& operator=(const stop_callback&) = delete;
stop_callback& operator=(stop_callback&&) = delete;
private:
shared_ptr<polyfill::stop_state> m_stop_state;
optional<polyfill::stop_state_callbacks::const_iterator> m_callback;
};
template <typename Callback>
stop_callback(stop_token, Callback) -> stop_callback<Callback>;
class jthread {
public:
using id = thread::id;
using native_handle_type = thread::native_handle_type;
jthread() noexcept = default;
template <typename F, typename... Args,
typename = enable_if_t<!is_same_v<remove_cvref_t<F>, jthread>>>
explicit jthread(F&& f, Args&&... args)
: m_stop_state(make_shared<polyfill::stop_state>()),
m_thread(make_thread(move(f), move(args)...)) {}
~jthread() {
if (joinable()) {
request_stop();
join();
}
}
jthread(const jthread&) = delete;
jthread(jthread&&) noexcept = default;
jthread& operator=(const jthread&) = delete;
jthread& operator=(jthread&& other) noexcept {
m_thread.swap(other.m_thread);
m_stop_state.swap(other.m_stop_state);
return *this;
}
void swap(jthread& other) noexcept {
m_thread.swap(other.m_thread);
m_stop_state.swap(other.m_stop_state);
}
[[nodiscard]] bool joinable() const noexcept {
return m_thread.joinable();
}
void join() {
m_thread.join();
}
void detach() {
m_thread.detach();
m_stop_state.reset();
}
[[nodiscard]] id get_id() const noexcept {
return m_thread.get_id();
}
[[nodiscard]] native_handle_type native_handle() {
return m_thread.native_handle();
}
[[nodiscard]] stop_source get_stop_source() noexcept {
return stop_source(m_stop_state);
}
[[nodiscard]] stop_token get_stop_token() const noexcept {
return stop_source(m_stop_state).get_token();
}
bool request_stop() noexcept {
return get_stop_source().request_stop();
}
[[nodiscard]] static unsigned int hardware_concurrency() noexcept {
return thread::hardware_concurrency();
}
private:
template <typename F, typename... Args>
thread make_thread(F&& f, Args&&... args) {
if constexpr (is_invocable_v<decay_t<F>, stop_token, decay_t<Args>...>) {
return thread(move(f), get_stop_token(), move(args)...);
} else {
return thread(move(f), move(args)...);
}
}
shared_ptr<polyfill::stop_state> m_stop_state;
thread m_thread;
};
} // namespace std
namespace Common {
template <typename Condvar, typename Lock, typename Pred>
void CondvarWait(Condvar& cv, Lock& lock, std::stop_token token, Pred pred) {
if (token.stop_requested()) {
return;
}
std::stop_callback callback(token, [&] { cv.notify_all(); });
cv.wait(lock, [&] { return pred() || token.stop_requested(); });
}
} // namespace Common
#endif
