pthread_condattr_setclock
int pthread_condattr_setclock(pthread_condattr_t *, clockid_t);
__weak_reference(_pthread_condattr_setclock, pthread_condattr_setclock);
if (pthread_condattr_setclock(&attr, CLOCK_MONOTONIC) != 0) {
error = pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);