vstinner wrote: > The glibc 2.30 adds pthread_cond_clockwait() which could be used to use > CLOCK_MONOTONIC. But if pthread_cond_clockwait() is available (glibc > 2.30 or newer), it expects that pthread_condattr_setclock() is also > available. So I'm not sure that it's worth it to change > PyCOND_TIMEDWAIT(). That's correct. The only time that pthread_cond_clockwait is essential is if you don't know which clock you're going to need to use for the wait at the time of condition variable creation. (This is true for a generic condition variable wrapper that can be passed absolute timeouts using different clocks like the C++ std::condition_variable.) However, sem_clockwait is the only way to wait on a semaphore using CLOCK_MONOTONIC, so it is worth using that rather than sem_timedwait if it's available. Similarly for pthread_mutex_clocklock.