1// RUN: %clangxx_tsan %s -o %t
2// RUN: not %run %t 5 2>&1 | FileCheck %s
3// RUN: not %run %t 10 2>&1 | FileCheck %s
4// RUN: not %run %t 15 2>&1 | FileCheck %s
5// RUN: not %run %t 20 2>&1 | FileCheck %s
6// RUN: %run %t 30 2>&1 | FileCheck %s --check-prefix=CHECK-TOO-LONG-CYCLE
7
8#include <pthread.h>
9#include <stdio.h>
10#include <stdlib.h>
11
12int main(int argc, char *argv[]) {
13 int num_mutexes = 5;
14 if (argc > 1) num_mutexes = atoi(argv[1]);
15
16 pthread_mutex_t m[num_mutexes];
17 for (int i = 0; i < num_mutexes; ++i)
18 pthread_mutex_init(&m[i], NULL);
19
20 for (int i = 0; i < num_mutexes - 1; ++i) {
21 pthread_mutex_lock(&m[i]);
22 pthread_mutex_lock(&m[i + 1]);
23
24 pthread_mutex_unlock(&m[i]);
25 pthread_mutex_unlock(&m[i + 1]);
26 }
27
28 pthread_mutex_lock(&m[num_mutexes - 1]);
29 pthread_mutex_lock(&m[0]);
30
31 pthread_mutex_unlock(&m[num_mutexes - 1]);
32 pthread_mutex_unlock(&m[0]);
33
34 for (int i = 0; i < num_mutexes; ++i)
35 pthread_mutex_destroy(&m[i]);
36
37 fprintf(stderr, "PASS\n");
38}
39
40// CHECK: ThreadSanitizer: lock-order-inversion (potential deadlock)
41// CHECK-TOO-LONG-CYCLE: WARNING: too long mutex cycle found
42// CHECK: PASS
43