// commit: 7e6be42a77989c01155bdc7333ea58206e1563d4 2011-03-08

// pthread_once should not deadlock

#include <pthread.h>

#include <semaphore.h>

#include <errno.h>

#include <string.h>

#include "test.h"

#define T(f) if ((r=(f))) t_error(#f " failed: %s\n", strerror(r))

#define E(f) if (f) t_error(#f " failed: %s\n", strerror(errno))

static int count;

static void init(void)

{

	count++;

}

static void *start(void *arg)

{

	void **a = arg;

	int r;

	E(sem_post(a[1]));

	T(pthread_once(a[0], init));

	E(sem_post(a[1]));

	return 0;

}

static int deadlocked(sem_t *s)

{

	struct timespec ts;

	E(sem_wait(s));

	E(clock_gettime(CLOCK_REALTIME, &ts);;

	ts.tv_nsec += 100*1000*1000;

	if (ts.tv_nsec >= 1000*1000*1000) {

		ts.tv_nsec -= 1000*1000*1000;

		ts.tv_sec += 1;

	}

	errno = 0;

	E(sem_timedwait(s,&ts);;

	if (errno != ETIMEDOUT)

		return 0;

	t_error("pthread_once deadlocked\n");

	return 1;

}

int main(void)

{

	pthread_t t1,t2,t3;

	pthread_once_t once = PTHREAD_ONCE_INIT;

	sem_t s1,s2,s3;

	void *p;

	int r;

	E(sem_init(&s1,0,0));

	E(sem_init(&s2,0,0));

	E(sem_init(&s3,0,0));

	T(pthread_create(&t1, 0, start, (void*[]){&once,&s1}));

	T(pthread_create(&t2, 0, start, (void*[]){&once,&s2}));

	T(pthread_create(&t3, 0, start, (void*[]){&once,&s3}));

	if (!deadlocked(&s1)) T(pthread_join(t1,&p);;

	if (!deadlocked(&s2)) T(pthread_join(t2,&p);;

	if (!deadlocked(&s3)) T(pthread_join(t3,&p);;

	if (count != 1)

		t_error("pthread_once ran init %d times instead of once\n", count);

	E(sem_destroy(&s1));

	E(sem_destroy(&s2));

	E(sem_destroy(&s3));

	return t_status;

}