1  #include <pthread.h>
       2  #include <stdio.h>
       3  #include <unistd.h>
       4  
       5  static int count = 0;
       6  
       7  static void *
       8  thread_add_one (void *arg)
       9  {
      10    int tmp;
      11    pthread_spinlock_t *lock = (pthread_spinlock_t *) arg;
      12  
      13    /* When do_test holds the lock for 1 sec, the two thread will be
      14       in contention for the lock. */
      15    if (pthread_spin_lock (lock) != 0)
      16      {
      17        puts ("thread_add_one(): spin_lock failed");
      18        pthread_exit ((void *) 1l);
      19      }
      20  
      21    /* sleep 1s before modifying count */
      22    tmp = count;
      23    sleep (1);
      24    count = tmp + 1;
      25  
      26    if (pthread_spin_unlock (lock) != 0)
      27      {
      28        puts ("thread_add_one(): spin_unlock failed");
      29        pthread_exit ((void *) 1l);
      30      }
      31  
      32    return NULL;
      33  }
      34  
      35  static int
      36  do_test (void)
      37  {
      38    pthread_t thr1, thr2;
      39    pthread_spinlock_t lock;
      40    int tmp;
      41  
      42    if (pthread_spin_init (&lock, PTHREAD_PROCESS_PRIVATE) != 0)
      43      {
      44        puts ("spin_init failed");
      45        return 1;
      46      }
      47  
      48    if (pthread_spin_lock (&lock) != 0)
      49      {
      50        puts ("1st spin_lock failed");
      51        return 1;
      52      }
      53  
      54    if (pthread_create (&thr1, NULL, thread_add_one, (void *) &lock) != 0)
      55      {
      56        puts ("1st pthread_create failed");
      57        return 1;
      58      }
      59  
      60    if (pthread_create (&thr2, NULL, thread_add_one, (void *) &lock) != 0)
      61      {
      62        puts ("2nd pthread_create failed");
      63        return 1;
      64      }
      65  
      66    /* sleep 1s before modifying count */
      67    tmp = count;
      68    sleep (1);
      69    count = tmp + 1;
      70  
      71    if (pthread_spin_unlock (&lock) != 0)
      72      {
      73        puts ("1st spin_unlock failed");
      74        return 1;
      75      }
      76  
      77    void *status;
      78    if (pthread_join (thr1, &status) != 0)
      79      {
      80        puts ("1st pthread_join failed");
      81        return 1;
      82      }
      83    if (status != NULL)
      84      {
      85        puts ("failure in the 1st thread");
      86        return 1;
      87      }
      88    if (pthread_join (thr2, &status) != 0)
      89      {
      90        puts ("2nd pthread_join failed");
      91        return 1;
      92      }
      93    if (status != NULL)
      94      {
      95        puts ("failure in the 2nd thread");
      96        return 1;
      97      }
      98  
      99    if (count != 3)
     100      {
     101        printf ("count is %d, should be 3\n", count);
     102        return 1;
     103      }
     104    return 0;
     105  }
     106  
     107  #define TEST_FUNCTION do_test ()
     108  #include "../test-skeleton.c"