compiler-rt/test/tsan/mutex_cycle_long.c

   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
  12 int 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