regress/lib/libpthread/once2/once2.c

   1 /*      $NetBSD$        */
   2
   3 #include <assert.h>
   4 #include <err.h>
   5 #include <pthread.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 pthread_once_t once = PTHREAD_ONCE_INIT;
  10 static int x;
  11
  12 #define NTHREADS 25
  13
  14 void ofunc(void);
  15 void* threadfunc(void *);
  16
  17 int
  18 main(int argc, char *argv[])
  19 {
  20         pthread_t  threads[NTHREADS];
  21         int id[NTHREADS];
  22         int i;
  23
  24         printf("1: Test 2 of pthread_once()\n");
  25
  26         for (i=0; i < NTHREADS; i++) {
  27                 id[i] = i;
  28                 pthread_create(&threads[i], NULL, threadfunc, &id[i]);
  29         }
  30
  31         for (i=0; i < NTHREADS; i++)
  32                 pthread_join(threads[i], NULL);
  33
  34         printf("1: X has value %d\n",x );
  35         assert(x == 2);
  36
  37         return 0;
  38 }
  39
  40
  41 void
  42 ofunc(void)
  43 {
  44         x++;
  45         printf("ofunc: Variable x has value %d\n", x);
  46         x++;
  47 }
  48
  49 void *
  50 threadfunc(void *arg)
  51 {
  52         int num;
  53
  54         pthread_once(&once, ofunc);
  55
  56         num = *(int *)arg;
  57         printf("Thread %d sees x with value %d\n", num, x);
  58         assert(x == 2);
  59
  60         return NULL;
  61 }