Waybar/include/util/sleeper_thread.hpp

127 lines
3.2 KiB
C++

#pragma once
#include <chrono>
#include <condition_variable>
#include <ctime>
#include <functional>
#include <thread>
#include "prepare_for_sleep.h"
namespace waybar::util {
/**
* Defer pthread_cancel until the end of a current scope.
*
* Required to protect a scope where it's unsafe to raise `__forced_unwind` exception.
* An example of these is a call of a method marked as `noexcept`; an attempt to cancel within such
* a method may result in a `std::terminate` call.
*/
class CancellationGuard {
int oldstate;
public:
CancellationGuard() { pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); }
~CancellationGuard() { pthread_setcancelstate(oldstate, &oldstate); }
};
class SleeperThread {
public:
SleeperThread() = default;
SleeperThread(std::function<void()> func)
: thread_{[this, func] {
while (do_run_) {
signal_ = false;
func();
}
}} {
connection_ = prepare_for_sleep().connect([this](bool sleep) {
if (not sleep) wake_up();
});
}
SleeperThread& operator=(std::function<void()> func) {
thread_ = std::thread([this, func] {
while (do_run_) {
signal_ = false;
func();
}
});
if (connection_.empty()) {
connection_ = prepare_for_sleep().connect([this](bool sleep) {
if (not sleep) wake_up();
});
}
return *this;
}
bool isRunning() const { return do_run_; }
auto sleep() {
std::unique_lock lk(mutex_);
CancellationGuard cancel_lock;
return condvar_.wait(lk, [this] { return signal_ || !do_run_; });
}
auto sleep_for(std::chrono::system_clock::duration dur) {
std::unique_lock lk(mutex_);
CancellationGuard cancel_lock;
using timepoint = std::chrono::system_clock::time_point;
static_assert(std::numeric_limits<timepoint::rep>::max() >=
std::numeric_limits<decltype(dur)::rep>::max());
if (std::chrono::system_clock::now() >= timepoint::max() - dur) {
dur = timepoint::max() - std::chrono::system_clock::now() - std::chrono::seconds(1);
}
return condvar_.wait_for(lk, dur, [this] { return signal_ || !do_run_; });
}
auto sleep_until(
std::chrono::time_point<std::chrono::system_clock, std::chrono::system_clock::duration>
time_point) {
std::unique_lock lk(mutex_);
CancellationGuard cancel_lock;
return condvar_.wait_until(lk, time_point, [this] { return signal_ || !do_run_; });
}
void wake_up() {
{
std::lock_guard<std::mutex> lck(mutex_);
signal_ = true;
}
condvar_.notify_all();
}
auto stop() {
{
std::lock_guard<std::mutex> lck(mutex_);
signal_ = true;
do_run_ = false;
}
condvar_.notify_all();
auto handle = thread_.native_handle();
if (handle != 0) {
// TODO: find a proper way to terminate thread...
pthread_cancel(handle);
}
}
~SleeperThread() {
connection_.disconnect();
stop();
if (thread_.joinable()) {
thread_.join();
}
}
private:
std::thread thread_;
std::condition_variable condvar_;
std::mutex mutex_;
bool do_run_ = true;
bool signal_ = false;
sigc::connection connection_;
};
} // namespace waybar::util