pthread_barrier_t
int pthread_barrier_destroy(pthread_barrier_t *);
int pthread_barrier_init(pthread_barrier_t * __restrict,
int pthread_barrier_wait(pthread_barrier_t *);
_pthread_barrier_destroy(pthread_barrier_t *barrier)
pthread_barrier_t bar;
_pthread_barrier_init(pthread_barrier_t * __restrict barrier,
pthread_barrier_t bar;
_pthread_barrier_wait(pthread_barrier_t *barrier)
pthread_barrier_t bar;
pthread_barrier_t bar;