helgrind/tests/locked_vs_unlocked1.c

   1
   2 #include <pthread.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6
   7 /* Test of the mechanism for showing all locks held by a thread -- one
   8    thread has a lock, the other doesn't.  Running w/ command line args
   9    switches the has/has-not thread around, so as to test lockset
  10    retention in both the history mechanism and the primary errors. */
  11
  12 pthread_mutex_t mx = PTHREAD_MUTEX_INITIALIZER;
  13
  14 int x = 0;
  15
  16 void* child_fn ( void* arg )
  17 {
  18    if (arg) pthread_mutex_lock(&mx);
  19    x = 1;
  20    if (arg) pthread_mutex_unlock(&mx);
  21    return NULL;
  22 }
  23
  24 int main ( int argc, char** argv )
  25 {
  26    int sw = argc > 1;
  27    pthread_t child1, child2;
  28
  29    if (pthread_create(&child1, NULL, child_fn, (void*)(long)(sw ? 0 : 1))) {
  30       perror("pthread_create1");
  31       exit(1);
  32    }
  33    sleep(1); /* ensure repeatable results */
  34    if (pthread_create(&child2, NULL, child_fn, (void*)(long)(sw ? 1 : 0))) {
  35       perror("pthread_create1");
  36       exit(1);
  37    }
  38
  39    if (pthread_join(child1, NULL)) {
  40       perror("pthread join1");
  41       exit(1);
  42    }
  43
  44    if (pthread_join(child2, NULL)) {
  45       perror("pthread join2");
  46       exit(1);
  47    }
  48
  49    return 0;
  50 }