pthread_test/protect/mutex_test.cc

   1 #include <stdio.h>
   2
   3 #include "threads.h"
   4 #include "librace.h"
   5 #include "stdatomic.h"
   6 #include <pthread.h>
   7
   8 int shareddata;
   9 pthread_mutex_t m;
  10
  11 static void* a(void *obj)
  12 {
  13         int i;
  14         for(i=0;i<2;i++) {
  15                 if ((i%2)==0) {
  16                         pthread_mutex_lock(&m);
  17                         store_32(&shareddata,(unsigned int)i);
  18                         printf("shareddata: %d\n", shareddata);
  19                         pthread_mutex_unlock(&m);
  20                 } else {
  21                         while(!pthread_mutex_trylock(&m))
  22                                 thrd_yield();
  23                         store_32(&shareddata,(unsigned int)i);
  24                         printf("shareddata: %d\n", shareddata);
  25                         pthread_mutex_unlock(&m);
  26                 }
  27         }
  28 }
  29
  30 int user_main(int argc, char **argv)
  31 {
  32         thrd_t t1, t2;
  33         pthread_mutex_init(&m, NULL);
  34
  35         thrd_create(&t1, (thrd_start_t)&a, NULL);
  36         thrd_create(&t2, (thrd_start_t)&a, NULL);
  37
  38         thrd_join(t1);
  39         thrd_join(t2);
  40         return 0;
  41 }