tools/lib/lockdep/tests/ABBA_2threads.c

   1 #include <stdio.h>
   2 #include <pthread.h>
   3
   4 pthread_mutex_t a = PTHREAD_MUTEX_INITIALIZER;
   5 pthread_mutex_t b = PTHREAD_MUTEX_INITIALIZER;
   6 pthread_barrier_t bar;
   7
   8 void *ba_lock(void *arg)
   9 {
  10         int ret, i;
  11
  12         pthread_mutex_lock(&b);
  13
  14         if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
  15                 pthread_barrier_destroy(&bar);
  16
  17         pthread_mutex_lock(&a);
  18
  19         pthread_mutex_unlock(&a);
  20         pthread_mutex_unlock(&b);
  21 }
  22
  23 int main(void)
  24 {
  25         pthread_t t;
  26
  27         pthread_barrier_init(&bar, NULL, 2);
  28
  29         if (pthread_create(&t, NULL, ba_lock, NULL)) {
  30                 fprintf(stderr, "pthread_create() failed\n");
  31                 return 1;
  32         }
  33         pthread_mutex_lock(&a);
  34
  35         if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
  36                 pthread_barrier_destroy(&bar);
  37
  38         pthread_mutex_lock(&b);
  39
  40         pthread_mutex_unlock(&b);
  41         pthread_mutex_unlock(&a);
  42
  43         pthread_join(t, NULL);
  44
  45         return 0;
  46 }