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

   1// SPDX-License-Identifier: GPL-2.0
   2#include <stdio.h>
   3#include <pthread.h>
   4
   5pthread_mutex_t a = PTHREAD_MUTEX_INITIALIZER;
   6pthread_mutex_t b = PTHREAD_MUTEX_INITIALIZER;
   7pthread_barrier_t bar;
   8
   9void *ba_lock(void *arg)
  10{
  11        int ret, i;
  12
  13        pthread_mutex_lock(&b);
  14
  15        if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
  16                pthread_barrier_destroy(&bar);
  17
  18        pthread_mutex_lock(&a);
  19
  20        pthread_mutex_unlock(&a);
  21        pthread_mutex_unlock(&b);
  22}
  23
  24int main(void)
  25{
  26        pthread_t t;
  27
  28        pthread_barrier_init(&bar, NULL, 2);
  29
  30        if (pthread_create(&t, NULL, ba_lock, NULL)) {
  31                fprintf(stderr, "pthread_create() failed\n");
  32                return 1;
  33        }
  34        pthread_mutex_lock(&a);
  35
  36        if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
  37                pthread_barrier_destroy(&bar);
  38
  39        pthread_mutex_lock(&b);
  40
  41        pthread_mutex_unlock(&b);
  42        pthread_mutex_unlock(&a);
  43
  44        pthread_join(t, NULL);
  45
  46        return 0;
  47}
  48