src/regression/pthread_once-deadlock.c

   1 // commit: 7e6be42a77989c01155bdc7333ea58206e1563d4 2011-03-08
   2 // pthread_once should not deadlock
   3 #include <pthread.h>
   4 #include <semaphore.h>
   5 #include <errno.h>
   6 #include <string.h>
   7 #include "test.h"
   8
   9 #define T(f) if ((r=(f))) t_error(#f " failed: %s\n", strerror(r))
  10 #define E(f) if (f) t_error(#f " failed: %s\n", strerror(errno))
  11
  12 static int count;
  13
  14 static void init(void)
  15 {
  16         count++;
  17 }
  18
  19 static void *start(void *arg)
  20 {
  21         void **a = arg;
  22         int r;
  23         E(sem_post(a[1]));
  24         T(pthread_once(a[0], init));
  25         E(sem_post(a[1]));
  26         return 0;
  27 }
  28
  29 static int deadlocked(sem_t *s)
  30 {
  31         struct timespec ts;
  32
  33         E(sem_wait(s));
  34         E(clock_gettime(CLOCK_REALTIME, &ts));
  35         ts.tv_nsec += 100*1000*1000;
  36         if (ts.tv_nsec >= 1000*1000*1000) {
  37                 ts.tv_nsec -= 1000*1000*1000;
  38                 ts.tv_sec += 1;
  39         }
  40         errno = 0;
  41         E(sem_timedwait(s,&ts));
  42         if (errno != ETIMEDOUT)
  43                 return 0;
  44         t_error("pthread_once deadlocked\n");
  45         return 1;
  46 }
  47
  48 int main(void)
  49 {
  50         pthread_t t1,t2,t3;
  51         pthread_once_t once = PTHREAD_ONCE_INIT;
  52         sem_t s1,s2,s3;
  53         void *a1[] = {&once, &s1};
  54         void *a2[] = {&once, &s2};
  55         void *a3[] = {&once, &s3};
  56         void *p;
  57         int r;
  58
  59         E(sem_init(&s1,0,0));
  60         E(sem_init(&s2,0,0));
  61         E(sem_init(&s3,0,0));
  62         T(pthread_create(&t1, 0, start, a1));
  63         T(pthread_create(&t2, 0, start, a2));
  64         T(pthread_create(&t3, 0, start, a3));
  65         if (!deadlocked(&s1)) T(pthread_join(t1,&p));
  66         if (!deadlocked(&s2)) T(pthread_join(t2,&p));
  67         if (!deadlocked(&s3)) T(pthread_join(t3,&p));
  68         if (count != 1)
  69                 t_error("pthread_once ran init %d times instead of once\n", count);
  70         E(sem_destroy(&s1));
  71         E(sem_destroy(&s2));
  72         E(sem_destroy(&s3));
  73         return t_status;
  74 }