LXR linux/tools/lib/lockdep/tests/ABBA

   1#include <stdio.h>
   2#include <pthread.h>
   3
   4pthread_mutex_t a = PTHREAD_MUTEX_INITIALIZER;
   5pthread_mutex_t b = PTHREAD_MUTEX_INITIALIZER;
   6pthread_barrier_t bar;
   7
   8void *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
  23int 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}
  47