suyu/src/common/thread.h
Lioncash 93f7677402 common/thread: Make Barrier's 'count' member non-const
While admirable as a means to ensure immutability, this has the
unfortunate downside of making the class non-movable. std::move cannot
actually perform a move operation if the provided operand has const data
members (std::move acts as an operation to "slide" resources out of an
object instance). Given Barrier contains move-only types such as
std::mutex, this can lead to confusing error messages if an object ever
contained a Barrier instance and said object was attempted to be moved.
2018-11-21 21:47:08 -05:00

86 lines
2.3 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 <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<std::mutex> lk(mutex);
if (!is_set) {
is_set = true;
condvar.notify_one();
}
}
void Wait() {
std::unique_lock<std::mutex> lk(mutex);
condvar.wait(lk, [&] { return is_set; });
is_set = false;
}
template <class Clock, class Duration>
bool WaitUntil(const std::chrono::time_point<Clock, Duration>& time) {
std::unique_lock<std::mutex> lk(mutex);
if (!condvar.wait_until(lk, time, [this] { return is_set; }))
return false;
is_set = false;
return true;
}
void Reset() {
std::unique_lock<std::mutex> 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:
bool is_set = false;
std::condition_variable condvar;
std::mutex mutex;
};
class Barrier {
public:
explicit Barrier(std::size_t count_) : count(count_) {}
/// Blocks until all "count" threads have called Sync()
void Sync() {
std::unique_lock<std::mutex> 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
};
void SetThreadAffinity(std::thread::native_handle_type thread, u32 mask);
void SetCurrentThreadAffinity(u32 mask);
void SwitchCurrentThread(); // On Linux, this is equal to sleep 1ms
void SetCurrentThreadName(const char* name);
} // namespace Common