pthread_rwlock_timedrdlock
extern int pthread_rwlock_timedrdlock(pthread_rwlock_t *_RESTRICT_KYWD,
if ((p = pthread_rwlock_timedrdlock(rwl, &clock_to_invns)) != 0) {
if ((p = pthread_rwlock_timedrdlock(rwl, &clock_to_invns)) != EINVAL) {
p = pthread_rwlock_timedrdlock(rwl, &to);