Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
/// relies on libwinpthread. Currently libwinpthread implements mutexes directly
/// on top of Windows semaphores. Semaphores, being kernel objects, require kernel
/// mode transition in order to lock or unlock, which is very slow compared to
-/// interlocked operations (about 30% slower on bench test). To workaround this
+/// interlocked operations (about 30% slower on bench test). To work around this
/// issue, we define our wrappers to the low level Win32 calls. We use critical
/// sections to support Windows XP and older versions. Unfortunately, cond_wait()
/// is racy between unlock() and WaitForSingleObject() but they have the same
-/// speed performance of SRW locks.
+/// speed performance as the SRW locks.
#include <condition_variable>
#include <mutex>
CRITICAL_SECTION cs;
};
-struct ConditionVariable {
- ConditionVariable() { hn = CreateEvent(0, FALSE, FALSE, 0); }
- ~ConditionVariable() { CloseHandle(hn); }
- void notify_one() { SetEvent(hn); }
-
- void wait(std::unique_lock<Mutex>& lk) {
- lk.unlock();
- WaitForSingleObject(hn, INFINITE);
- lk.lock();
- }
-
- void wait_for(std::unique_lock<Mutex>& lk, const std::chrono::milliseconds& ms) {
- lk.unlock();
- WaitForSingleObject(hn, ms.count());
- lk.lock();
- }
-
- template<class Predicate>
- void wait(std::unique_lock<Mutex>& lk, Predicate p) { while (!p()) this->wait(lk); }
-
-private:
- HANDLE hn;
-};
+typedef std::condition_variable_any ConditionVariable;
#else // Default case: use STL classes