1 // Test that the deadlock detector can find a deadlock that actually happened.
2 // Currently we will fail to report such a deadlock because we check for
3 // cycles in lock-order graph after pthread_mutex_lock.
4
5 // RUN: %clangxx_tsan %s -o %t
6 // RUN: not %run %t 2>&1 | FileCheck %s
7 // XFAIL: *
8 #include <pthread.h>
9 #include <stdio.h>
10 #include <unistd.h>
11
12 pthread_mutex_t mu1, mu2;
13 pthread_barrier_t barrier;
14
Thread(void * p)15 void *Thread(void *p) {
16 // mu2 => mu1
17 pthread_mutex_lock(&mu2);
18 pthread_barrier_wait(&barrier);
19 pthread_mutex_lock(&mu1);
20 // CHECK: ThreadSanitizer: lock-order-inversion (potential deadlock)
21 pthread_mutex_unlock(&mu1);
22 pthread_mutex_unlock(&mu2);
23 return p;
24 }
25
main()26 int main() {
27 pthread_mutex_init(&mu1, NULL);
28 pthread_mutex_init(&mu2, NULL);
29 pthread_barrier_init(&barrier, 0, 2);
30
31 fprintf(stderr, "This test is going to deadlock and die in 3 seconds\n");
32 alarm(3);
33
34 pthread_t t;
35 pthread_create(&t, 0, Thread, 0);
36
37 // mu1 => mu2
38 pthread_mutex_lock(&mu1);
39 pthread_barrier_wait(&barrier);
40 pthread_mutex_lock(&mu2);
41 pthread_mutex_unlock(&mu2);
42 pthread_mutex_unlock(&mu1);
43
44 pthread_join(t, 0);
45
46 pthread_mutex_destroy(&mu1);
47 pthread_mutex_destroy(&mu2);
48 pthread_barrier_destroy(&barrier);
49 fprintf(stderr, "FAILED\n");
50 }
51