drd/tests/hold_lock.c

   1 /** Hold several types of synchronization objects locked as long as specified.
   2  */
   3
   4 #define _GNU_SOURCE 1
   5
   6 #include <assert.h>
   7 #include <pthread.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <time.h>
  11 #include <unistd.h>
  12
  13
  14 static void delay_ms(const int ms)
  15 {
  16   struct timespec ts;
  17
  18   assert(ms >= 0);
  19   ts.tv_sec = ms / 1000;
  20   ts.tv_nsec = (ms % 1000) * 1000 * 1000;
  21   nanosleep(&ts, 0);
  22 }
  23
  24 int main(int argc, char** argv)
  25 {
  26   int interval = 0;
  27   int optchar;
  28   pthread_mutex_t     mutex;
  29   pthread_mutexattr_t mutexattr;
  30   pthread_rwlock_t    rwlock;
  31
  32   while ((optchar = getopt(argc, argv, "i:")) != EOF)
  33   {
  34     switch (optchar)
  35     {
  36     case 'i':
  37       interval = atoi(optarg);
  38       break;
  39     default:
  40       fprintf(stderr, "Usage: %s [-i <interval time in ms>].\n", argv[0]);
  41       break;
  42     }
  43   }
  44
  45   fprintf(stderr, "Locking mutex ...\n");
  46
  47   pthread_mutexattr_init(&mutexattr);
  48   pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_RECURSIVE);
  49   pthread_mutex_init(&mutex, &mutexattr);
  50   pthread_mutexattr_destroy(&mutexattr);
  51   pthread_mutex_lock(&mutex);
  52   delay_ms(interval);
  53   pthread_mutex_lock(&mutex);
  54   pthread_mutex_unlock(&mutex);
  55   pthread_mutex_unlock(&mutex);
  56   pthread_mutex_destroy(&mutex);
  57
  58   fprintf(stderr, "Locking rwlock exclusively ...\n");
  59
  60   pthread_rwlock_init(&rwlock, 0);
  61   pthread_rwlock_wrlock(&rwlock);
  62   delay_ms(interval);
  63   pthread_rwlock_unlock(&rwlock);
  64   pthread_rwlock_destroy(&rwlock);
  65
  66   fprintf(stderr, "Locking rwlock shared ...\n");
  67
  68   pthread_rwlock_init(&rwlock, 0);
  69   pthread_rwlock_rdlock(&rwlock);
  70   delay_ms(interval);
  71   pthread_rwlock_rdlock(&rwlock);
  72   pthread_rwlock_unlock(&rwlock);
  73   pthread_rwlock_unlock(&rwlock);
  74   pthread_rwlock_destroy(&rwlock);
  75
  76   fprintf(stderr, "Done.\n");
  77
  78   return 0;
  79 }