suyu/src/common/thread.h
ReinUsesLisp f119ef798b common/thread: Fix data race in is_set
As report by tsan, Event::Set can write is_set while WaitFor and friends
are reading from it. To address this issue, make is_set an atomic.
2020-08-26 02:50:51 +00:00

101 lines
2.5 KiB
C++

// Copyright 2013 Dolphin Emulator Project / 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <cstddef>
#include <mutex>
#include <thread>
#include "common/common_types.h"
namespace Common {
class Event {
public:
void Set() {
std::lock_guard lk{mutex};
if (!is_set) {
is_set = true;
condvar.notify_one();
}
}
void Wait() {
std::unique_lock lk{mutex};
condvar.wait(lk, [&] { return is_set.load(); });
is_set = false;
}
bool WaitFor(const std::chrono::nanoseconds& time) {
std::unique_lock lk{mutex};
if (!condvar.wait_for(lk, time, [this] { return is_set.load(); }))
return false;
is_set = false;
return true;
}
template <class Clock, class Duration>
bool WaitUntil(const std::chrono::time_point<Clock, Duration>& time) {
std::unique_lock lk{mutex};
if (!condvar.wait_until(lk, time, [this] { return is_set.load(); }))
return false;
is_set = false;
return true;
}
void Reset() {
std::unique_lock lk{mutex};
// no other action required, since wait loops on the predicate and any lingering signal will
// get cleared on the first iteration
is_set = false;
}
private:
std::condition_variable condvar;
std::mutex mutex;
std::atomic_bool is_set{false};
};
class Barrier {
public:
explicit Barrier(std::size_t count_) : count(count_) {}
/// Blocks until all "count" threads have called Sync()
void Sync() {
std::unique_lock lk{mutex};
const std::size_t current_generation = generation;
if (++waiting == count) {
generation++;
waiting = 0;
condvar.notify_all();
} else {
condvar.wait(lk,
[this, current_generation] { return current_generation != generation; });
}
}
private:
std::condition_variable condvar;
std::mutex mutex;
std::size_t count;
std::size_t waiting = 0;
std::size_t generation = 0; // Incremented once each time the barrier is used
};
enum class ThreadPriority : u32 {
Low = 0,
Normal = 1,
High = 2,
VeryHigh = 3,
};
void SetCurrentThreadPriority(ThreadPriority new_priority);
void SetCurrentThreadName(const char* name);
} // namespace Common