1 // RUN: %clangxx_tsan -O1 --std=c++11 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
2 #include "custom_mutex.h"
3 
4 // Test that failed TryLock does not induce parasitic synchronization.
5 
6 Mutex mu(true, 0);
7 long data;
8 
thr(void * arg)9 void *thr(void *arg) {
10   mu.Lock();
11   data++;
12   mu.Unlock();
13   mu.Lock();
14   barrier_wait(&barrier);
15   barrier_wait(&barrier);
16   mu.Unlock();
17   return 0;
18 }
19 
main()20 int main() {
21   barrier_init(&barrier, 2);
22   pthread_t th;
23   pthread_create(&th, 0, thr, 0);
24   barrier_wait(&barrier);
25   if (mu.TryLock()) {
26     fprintf(stderr, "TryLock succeeded, should not\n");
27     exit(0);
28   }
29   data++;
30   barrier_wait(&barrier);
31   pthread_join(th, 0);
32   fprintf(stderr, "DONE\n");
33   return 0;
34 }
35 
36 // CHECK: ThreadSanitizer: data race
37 // CHECK-NEXT:   Write of size 8 at {{.*}} by main thread:
38 // CHECK-NEXT:     #0 main {{.*}}custom_mutex1.cpp:29
39 // CHECK: DONE
40