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   fprintf(stderr, "Hello world.\n");
12 
13   dispatch_queue_t q = dispatch_queue_create("my.queue", DISPATCH_QUEUE_SERIAL);
14   dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, q);
15   long long interval_ms = 10;
16   dispatch_source_set_timer(timer, dispatch_time(DISPATCH_TIME_NOW, 0), interval_ms * NSEC_PER_MSEC, 0);
17 
18   dispatch_semaphore_t sem = dispatch_semaphore_create(0);
19   dispatch_source_set_event_handler(timer, ^{
20     fprintf(stderr, "timer\n");
21     global++;
22 
23     if (global > 50) {
24       dispatch_semaphore_signal(sem);
25       dispatch_suspend(timer);
26     }
27   });
28   dispatch_resume(timer);
29 
30   dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
31 
32   fprintf(stderr, "Done.\n");
33 }
34 
35 // CHECK: Hello world.
36 // CHECK: timer
37 // CHECK: Done.
38 // CHECK-NOT: timer
39