regress/lib/libpthread/preempt1/preempt1.c

   1 /*      $NetBSD: preempt1.c,v 1.2 2003/06/27 13:27:58 skrll Exp $       */
   2
   3 #include <assert.h>
   4 #include <err.h>
   5 #include <fcntl.h>
   6 #include <pthread.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10
  11 void *threadfunc(void *arg);
  12
  13 pthread_mutex_t mutex;
  14 pthread_cond_t cond;
  15 int started;
  16
  17 #define HUGE_BUFFER     1<<20
  18 #define NTHREADS        1
  19
  20 int
  21 main(int argc, char *argv[])
  22 {
  23         int ret, i;
  24         pthread_t new;
  25         void *joinval;
  26
  27         char *mem;
  28         int fd;
  29
  30         mem = malloc(HUGE_BUFFER);
  31         if (mem == NULL)
  32                 err(1, "malloc");
  33
  34         fd = open("/dev/urandom", O_RDONLY, 0);
  35         if (fd == -1)
  36                 err(1, "open");
  37
  38         printf("1: preempt test\n");
  39
  40         pthread_cond_init(&cond, NULL);
  41         pthread_mutex_init(&mutex, NULL);
  42
  43         pthread_mutex_lock(&mutex);
  44
  45         started = 0;
  46
  47         for (i = 0; i < NTHREADS; i++) {
  48                 ret = pthread_create(&new, NULL, threadfunc, NULL);
  49                 if (ret != 0)
  50                         err(1, "pthread_create");
  51         }
  52
  53         while (started < NTHREADS) {
  54                 pthread_cond_wait(&cond, &mutex);
  55         }
  56
  57         printf("1: Thread has started.\n");
  58
  59         pthread_mutex_unlock(&mutex);
  60         printf("1: After releasing the mutex.\n");
  61
  62         ret = read(fd, mem, HUGE_BUFFER);
  63         close(fd);
  64
  65         assert(ret == HUGE_BUFFER);
  66
  67         ret = pthread_join(new, &joinval);
  68         if (ret != 0)
  69                 err(1, "pthread_join");
  70
  71         printf("1: Thread joined.\n");
  72
  73         return 0;
  74 }
  75
  76 void *
  77 threadfunc(void *arg)
  78 {
  79         printf("2: Second thread.\n");
  80
  81         printf("2: Locking mutex\n");
  82         pthread_mutex_lock(&mutex);
  83         printf("2: Got mutex.\n");
  84         started++;
  85
  86         pthread_mutex_unlock(&mutex);
  87         pthread_cond_signal(&cond);
  88         sleep(1);
  89
  90         return NULL;
  91 }