pthread_test/deadlock.cc

   1 #include <stdio.h>
   2 #include <pthread.h>
   3
   4 #include "librace.h"
   5
   6 pthread_mutex_t x;
   7 pthread_mutex_t y;
   8 uint32_t shared = 0;
   9
  10 static void *a(void *obj)
  11 {
  12         pthread_mutex_lock(&x);
  13         pthread_mutex_lock(&y);
  14         printf("shared = %u\n", load_32(&shared));
  15         pthread_mutex_unlock(&y);
  16         pthread_mutex_unlock(&x);
  17         return NULL;
  18 }
  19
  20 static void *b(void *obj)
  21 {
  22         pthread_mutex_lock(&y);
  23         pthread_mutex_lock(&x);
  24         store_32(&shared, 16);
  25         printf("write shared = 16\n");
  26         pthread_mutex_unlock(&x);
  27         pthread_mutex_unlock(&y);
  28         return NULL;
  29 }
  30
  31 int user_main(int argc, char **argv)
  32 {
  33         pthread_t t1, t2;
  34
  35         pthread_mutex_init(&x, NULL);
  36         pthread_mutex_init(&y, NULL);
  37
  38         printf("Main thread: creating 2 threads\n");
  39         pthread_create(&t1,NULL, &a, NULL);
  40         pthread_create(&t2,NULL, &b, NULL);
  41
  42         pthread_join(t1,NULL);
  43         pthread_join(t2,NULL);
  44         printf("Main thread is finished\n");
  45
  46         return 0;
  47 }