1 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 // CHECK-NOT: WARNING: ThreadSanitizer: data race
3 // CHECK-NOT: ThreadSanitizer WARNING: double lock
4 // CHECK-NOT: ThreadSanitizer WARNING: mutex unlock by another thread
5 // CHECK: OK
6 
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <pthread.h>
10 
11 pthread_mutex_t m;
12 pthread_cond_t c;
13 int x;
14 
thr1(void * p)15 void *thr1(void *p) {
16   int i;
17 
18   for (i = 0; i < 10; i += 2) {
19     pthread_mutex_lock(&m);
20     while (x != i)
21       pthread_cond_wait(&c, &m);
22     x = i + 1;
23     pthread_cond_signal(&c);
24     pthread_mutex_unlock(&m);
25   }
26   return 0;
27 }
28 
thr2(void * p)29 void *thr2(void *p) {
30   int i;
31 
32   for (i = 1; i < 10; i += 2) {
33     pthread_mutex_lock(&m);
34     while (x != i)
35       pthread_cond_wait(&c, &m);
36     x = i + 1;
37     pthread_mutex_unlock(&m);
38     pthread_cond_broadcast(&c);
39   }
40   return 0;
41 }
42 
main()43 int main() {
44   pthread_t th1, th2;
45 
46   pthread_mutex_init(&m, 0);
47   pthread_cond_init(&c, 0);
48   pthread_create(&th1, 0, thr1, 0);
49   pthread_create(&th2, 0, thr2, 0);
50   pthread_join(th1, 0);
51   pthread_join(th2, 0);
52   fprintf(stderr, "OK\n");
53 }
54