1 // RUN: %clang_tsan %s -o %t
2 // RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not='ThreadSanitizer'
3
4 #include <dispatch/dispatch.h>
5
6 #include "../test.h"
7
8 static const long kNumThreads = 4;
9
10 long global;
11 long global2;
12
13 static dispatch_once_t once_token;
14 static dispatch_once_t once_token2;
15
f(void * a)16 void f(void *a) {
17 global2 = 42;
18 usleep(100000);
19 }
20
Thread(void * a)21 void *Thread(void *a) {
22 barrier_wait(&barrier);
23
24 dispatch_once(&once_token, ^{
25 global = 42;
26 usleep(100000);
27 });
28 long x = global;
29
30 dispatch_once_f(&once_token2, NULL, f);
31 long x2 = global2;
32
33 fprintf(stderr, "global = %ld\n", x);
34 fprintf(stderr, "global2 = %ld\n", x2);
35 return 0;
36 }
37
main()38 int main() {
39 fprintf(stderr, "Hello world.\n");
40 barrier_init(&barrier, kNumThreads);
41
42 pthread_t t[kNumThreads];
43 for (int i = 0; i < kNumThreads; i++) {
44 pthread_create(&t[i], 0, Thread, 0);
45 }
46 for (int i = 0; i < kNumThreads; i++) {
47 pthread_join(t[i], 0);
48 }
49
50 fprintf(stderr, "Done.\n");
51 }
52
53 // CHECK: Hello world.
54 // CHECK: Done.
55