Thread: Make Barrier reusable

This commit is contained in:
MerryMage 2016-04-14 12:54:06 +01:00
parent 8c50833445
commit 3c710f9b10

View file

@ -69,20 +69,19 @@ private:
class Barrier { class Barrier {
public: public:
explicit Barrier(size_t count_) : count(count_), waiting(0) {} explicit Barrier(size_t count_) : count(count_), waiting(0), generation(0) {}
/// Blocks until all "count" threads have called Sync() /// Blocks until all "count" threads have called Sync()
void Sync() { void Sync() {
std::unique_lock<std::mutex> lk(mutex); std::unique_lock<std::mutex> lk(mutex);
const size_t current_generation = generation;
// TODO: broken when next round of Sync()s
// is entered before all waiting threads return from the notify_all
if (++waiting == count) { if (++waiting == count) {
generation++;
waiting = 0; waiting = 0;
condvar.notify_all(); condvar.notify_all();
} else { } else {
condvar.wait(lk, [&]{ return waiting == 0; }); condvar.wait(lk, [this, current_generation]{ return current_generation != generation; });
} }
} }
@ -91,6 +90,7 @@ private:
std::mutex mutex; std::mutex mutex;
const size_t count; const size_t count;
size_t waiting; size_t waiting;
size_t generation; // Incremented once each time the barrier is used
}; };
void SleepCurrentThread(int ms); void SleepCurrentThread(int ms);