test/fences.c

   1 #include <stdio.h>
   2 #include <threads.h>
   3 #include <stdatomic.h>
   4
   5 #include "librace.h"
   6
   7 atomic_int x;
   8 atomic_int y;
   9
  10 static void a(void *obj)
  11 {
  12         atomic_store_explicit(&x, 1, memory_order_relaxed);
  13         atomic_store_explicit(&x, 2, memory_order_relaxed);
  14         atomic_thread_fence(memory_order_seq_cst);
  15         printf("Thread A reads: %d\n", atomic_load_explicit(&y, memory_order_relaxed));
  16 }
  17
  18 static void b(void *obj)
  19 {
  20         atomic_store_explicit(&y, 1, memory_order_relaxed);
  21         atomic_store_explicit(&y, 2, memory_order_relaxed);
  22         atomic_thread_fence(memory_order_seq_cst);
  23         printf("Thread B reads: %d\n", atomic_load_explicit(&x, memory_order_relaxed));
  24 }
  25
  26 int user_main(int argc, char **argv)
  27 {
  28         thrd_t t1, t2;
  29
  30         atomic_init(&x, 0);
  31         atomic_init(&y, 0);
  32
  33         printf("Main thread: creating 2 threads\n");
  34         thrd_create(&t1, (thrd_start_t)&a, NULL);
  35         thrd_create(&t2, (thrd_start_t)&b, NULL);
  36
  37         thrd_join(t1);
  38         thrd_join(t2);
  39         printf("Main thread is finishing\n");
  40
  41         return 0;
  42 }