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#include <pthread.h>
#include <unistd.h>
#include <assert.h>
pthread_barrier_t barrier;
_Atomic int hitBarrierCount, pastBarrierCount;
static void *worker(void *arg) {
(void)arg;
hitBarrierCount++;
pthread_barrier_wait(&barrier);
pastBarrierCount++;
return NULL;
}
int main() {
// pthread_barrierattr_t
pthread_barrierattr_t attr;
pthread_barrierattr_init(&attr);
int pshared;
pthread_barrierattr_getpshared(&attr, &pshared);
assert(pshared == PTHREAD_PROCESS_PRIVATE);
pthread_barrierattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
pthread_barrierattr_getpshared(&attr, &pshared);
assert(pshared == PTHREAD_PROCESS_SHARED);
pthread_barrierattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE);
pthread_barrierattr_getpshared(&attr, &pshared);
assert(pshared == PTHREAD_PROCESS_PRIVATE);
// pthread_barrier_t
pthread_barrier_init(&barrier, &attr, 3);
pthread_barrierattr_destroy(&attr);
pthread_t thread1;
int ret = pthread_create(&thread1, NULL, &worker, NULL);
assert(!ret);
pthread_t thread2;
ret = pthread_create(&thread2, NULL, &worker, NULL);
assert(!ret);
sleep(1);
// Make sure the barrier actually stops threads from proceeding.
assert(pastBarrierCount == 0);
assert(hitBarrierCount <= 2);
hitBarrierCount++;
pthread_barrier_wait(&barrier);
assert(hitBarrierCount == 3);
pthread_barrier_destroy(&barrier);
}
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