drd/tests/recursive_mutex.c

   1 /** Initialize several kinds of mutexes and lock each mutex twice.
   2  *  Note: locking a regular mutex twice causes a deadlock.
   3  */
   4
   5 #define _GNU_SOURCE
   6
   7 #include <stdio.h>
   8 #include <unistd.h>
   9 #include <pthread.h>
  10 #include "../../config.h"
  11
  12
  13 static void lock_twice(pthread_mutex_t* const p)
  14 {
  15   if (pthread_mutex_trylock(p) != 0)
  16     fprintf(stderr, "first lock call failed !\n");
  17   if (pthread_mutex_trylock(p) != 0)
  18     fprintf(stderr, "second lock call failed !\n");
  19   if (pthread_mutex_unlock(p) != 0)
  20     fprintf(stderr, "first unlock call failed !\n");
  21   if (pthread_mutex_unlock(p) != 0)
  22     fprintf(stderr, "second unlock call failed !\n");
  23 }
  24
  25 int main(int argc, char** argv)
  26 {
  27 #if defined(HAVE_PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP)
  28   {
  29     pthread_mutex_t m = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
  30
  31     fprintf(stderr, "Recursive mutex (statically initialized).\n");
  32     lock_twice(&m);
  33     pthread_mutex_destroy(&m);
  34   }
  35 #endif
  36 #if defined(HAVE_PTHREAD_MUTEX_RECURSIVE_NP)
  37   {
  38     pthread_mutex_t m;
  39     pthread_mutexattr_t attr;
  40
  41     fprintf(stderr, "\nRecursive mutex (initialized via mutex attributes).\n");
  42     pthread_mutexattr_init(&attr);
  43     pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE_NP);
  44     pthread_mutex_init(&m, &attr);
  45     pthread_mutexattr_destroy(&attr);
  46     lock_twice(&m);
  47     pthread_mutex_destroy(&m);
  48   }
  49 #endif
  50 #if defined(HAVE_PTHREAD_MUTEX_ERRORCHECK_NP)
  51   {
  52     pthread_mutex_t m;
  53     pthread_mutexattr_t attr;
  54
  55     fprintf(stderr, "\nError checking mutex.\n");
  56     pthread_mutexattr_init(&attr);
  57     pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK_NP);
  58     pthread_mutex_init(&m, &attr);
  59     pthread_mutexattr_destroy(&attr);
  60     lock_twice(&m);
  61     pthread_mutex_destroy(&m);
  62   }
  63 #endif
  64
  65   {
  66     pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
  67
  68     fprintf(stderr, "\nNon-recursive mutex.\n");
  69     lock_twice(&m);
  70   }
  71
  72   fprintf(stderr, "\nDone.\n");
  73
  74   return 0;
  75 }