--- /dev/null
+// 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;
+}