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.
This commit is contained in:
ReinUsesLisp 2020-08-26 01:41:46 +00:00
parent 4efaecf125
commit f119ef798b

View file

@ -4,6 +4,7 @@
#pragma once #pragma once
#include <atomic>
#include <chrono> #include <chrono>
#include <condition_variable> #include <condition_variable>
#include <cstddef> #include <cstddef>
@ -25,13 +26,13 @@ public:
void Wait() { void Wait() {
std::unique_lock lk{mutex}; std::unique_lock lk{mutex};
condvar.wait(lk, [&] { return is_set; }); condvar.wait(lk, [&] { return is_set.load(); });
is_set = false; is_set = false;
} }
bool WaitFor(const std::chrono::nanoseconds& time) { bool WaitFor(const std::chrono::nanoseconds& time) {
std::unique_lock lk{mutex}; std::unique_lock lk{mutex};
if (!condvar.wait_for(lk, time, [this] { return is_set; })) if (!condvar.wait_for(lk, time, [this] { return is_set.load(); }))
return false; return false;
is_set = false; is_set = false;
return true; return true;
@ -40,7 +41,7 @@ public:
template <class Clock, class Duration> template <class Clock, class Duration>
bool WaitUntil(const std::chrono::time_point<Clock, Duration>& time) { bool WaitUntil(const std::chrono::time_point<Clock, Duration>& time) {
std::unique_lock lk{mutex}; std::unique_lock lk{mutex};
if (!condvar.wait_until(lk, time, [this] { return is_set; })) if (!condvar.wait_until(lk, time, [this] { return is_set.load(); }))
return false; return false;
is_set = false; is_set = false;
return true; return true;
@ -54,9 +55,9 @@ public:
} }
private: private:
bool is_set = false;
std::condition_variable condvar; std::condition_variable condvar;
std::mutex mutex; std::mutex mutex;
std::atomic_bool is_set{false};
}; };
class Barrier { class Barrier {