int pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex, const struct timespec * abstime);
int pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex);
int pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex, const struct timespec * abstime);
int pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex);