1 // Check that dispatch_once() is always intercepted.
2 
3 // RUN: %clang_tsan %s -o %t
4 // RUN: not %env_tsan_opts=ignore_noninstrumented_modules=0 %run %t 2>&1 | FileCheck %s
5 
6 #include <dispatch/dispatch.h>
7 
8 #include <pthread.h>
9 #include <stdio.h>
10 
11 #include "../test.h"
12 
13 long g = 0;
14 long h = 0;
15 
16 __attribute__((disable_sanitizer_instrumentation))
17 void f() {
18   static dispatch_once_t onceToken;
19   dispatch_once(&onceToken, ^{
20     g++;
21   });
22   h++;
23 }
24 
25 __attribute__((disable_sanitizer_instrumentation))
26 void __tsan_on_report() {
27   fprintf(stderr, "Report.\n");
28 
29   // Without these annotations this test deadlocks for COMPILER_RT_DEBUG=ON
30   // builds.  Conceptually, the TSan runtime does not support reentrancy from
31   // runtime callbacks, but the main goal here is just to check that
32   // dispatch_once() is always intercepted.
33   AnnotateIgnoreSyncBegin(__FILE__, __LINE__);
34   f();
35   AnnotateIgnoreSyncEnd(__FILE__, __LINE__);
36 }
37 
38 int main() {
39   fprintf(stderr, "Hello world.\n");
40 
41   f();
42 
43   pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
44   pthread_mutex_unlock(&mutex); // Unlock of an unlocked mutex
45 
46   fprintf(stderr, "g = %ld.\n", g);
47   fprintf(stderr, "h = %ld.\n", h);
48   fprintf(stderr, "Done.\n");
49 }
50 
51 // CHECK: Hello world.
52 // CHECK: Report.
53 // CHECK: g = 1
54 // CHECK: h = 2
55 // CHECK: Done.
56