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 <stdio.h>
7 
8 long global;
9 
10 int main(int argc, const char *argv[]) {
11   dispatch_semaphore_t done = dispatch_semaphore_create(0);
12 
13   dispatch_queue_t queue =
14       dispatch_queue_create("my.queue", DISPATCH_QUEUE_CONCURRENT);
15 
16   dispatch_source_t source =
17       dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
18 
19   dispatch_source_set_timer(source, dispatch_walltime(NULL, 0), 1e9, 5);
20 
21   global = 42;
22 
23   dispatch_source_set_cancel_handler(source, ^{
24     fprintf(stderr, "global = %ld\n", global);
25 
26     dispatch_semaphore_signal(done);
27   });
28 
29   dispatch_resume(source);
30   dispatch_cancel(source);
31 
32   dispatch_semaphore_wait(done, DISPATCH_TIME_FOREVER);
33 
34   return 0;
35 }
36 
37 // CHECK: global = 42
38