helgrind/tests/tc09_bad_unlock.c

   1
   2 /* Check that an error is reported for various kinds of bogus
   3    pthread_mutex_unlock calls. */
   4
   5 #include <pthread.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include "config.h"
   9
  10 void* child_fn ( void* arg )
  11 {
  12    pthread_mutex_unlock( (pthread_mutex_t*)arg ); /* ERROR */
  13    return NULL;
  14 }
  15
  16 void nearly_main ( void )
  17 {
  18    pthread_t child;
  19    pthread_mutex_t mx1, mx2;
  20    int bogus[100], i;
  21    /* fill bogus with values which will cause glibc's pth_mx_unlock to fail */
  22    for (i = 0; i < 100; i++) bogus[i] = 0xFFFFFFFF;
  23    /* Unlocking a lock that is already unlocked */
  24    pthread_mutex_init( &mx1, NULL );
  25    pthread_mutex_lock( &mx1 );
  26    pthread_mutex_unlock( &mx1 );
  27
  28    pthread_mutex_unlock( &mx1 ); /* ERROR */
  29
  30    /* Unlocking a lock that is held by a different thread */
  31
  32    pthread_mutex_init( &mx2, NULL );
  33    pthread_mutex_lock( &mx2 );
  34    // start child and get it to unlock this lock
  35
  36    pthread_create( &child, NULL, child_fn, (void*)&mx2 );
  37       /* child runs and attempts to unlock our lock.  Error
  38          is reported in child_fn. */
  39    pthread_join(child, NULL );
  40
  41 #if !defined(VGO_freebsd)
  42    /* Unlocking a totally bogus lock. */
  43    pthread_mutex_unlock( (pthread_mutex_t*) &bogus[50] ); /* ERROR */
  44 #endif
  45
  46    /* Now we get a freeing-locked-lock error, since the stack
  47       frame is removed whilst mx2 is still locked. */
  48 }
  49
  50 int main ( void )
  51 {
  52    nearly_main(); fprintf(stderr, "---------------------\n" );
  53    nearly_main();
  54    return 0;
  55 }