htl/tests/test-6.c

   1 /* Test barriers.
   2    Copyright (C) 2000-2020 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library;  if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define _GNU_SOURCE
  20
  21 #include <pthread.h>
  22 #include <stdio.h>
  23 #include <error.h>
  24 #include <assert.h>
  25 #include <errno.h>
  26
  27 #define THREADS 500
  28 #define WAITS 3
  29
  30 void *
  31 dowait (void *arg)
  32 {
  33   pthread_barrier_t *barrier = arg;
  34   int ret;
  35
  36   ret = pthread_barrier_wait (barrier);
  37   printf ("%d ", pthread_self ());
  38   return (void *) ret;
  39 }
  40
  41 int
  42 main (int argc, char **argv)
  43 {
  44   pthread_barrierattr_t attr;
  45   pthread_barrier_t barrier;
  46
  47   int i, j;
  48   error_t err;
  49   pthread_t tid[THREADS];
  50
  51   int havesyncs;
  52
  53   err = pthread_barrierattr_init (&attr);
  54   if (err)
  55     error (1, err, "pthread_barrierattr_init");
  56
  57   err = pthread_barrierattr_getpshared (&attr, &i);
  58   if (err)
  59     error (1, err, "pthread_barrierattr_getpshared");
  60   assert (i == PTHREAD_PROCESS_PRIVATE || i == PTHREAD_PROCESS_SHARED);
  61
  62   err = pthread_barrierattr_setpshared (&attr, PTHREAD_PROCESS_PRIVATE);
  63   if (err)
  64     error (1, err, "pthread_barrierattr_setpshared");
  65
  66   err = pthread_barrier_init (&barrier, &attr, THREADS + 1);
  67   if (err)
  68     error (1, err, "pthread_barrier_init");
  69
  70   for (j = 0; j < WAITS; j++)
  71     {
  72
  73       for (i = 0; i < THREADS; i++)
  74         {
  75           err = pthread_create (&tid[i], 0, dowait, &barrier);
  76           if (err)
  77             error (1, err, "pthread_create (%d)", i);
  78         }
  79
  80       printf ("Manager will now call pthread_barrier_wait.\n");
  81
  82       havesyncs
  83           = pthread_barrier_wait (&barrier) == PTHREAD_BARRIER_SERIAL_THREAD
  84           ? 1 : 0;
  85
  86       for (i = THREADS - 1; i >= 0; i--)
  87         {
  88           void *ret;
  89           err = pthread_join (tid[i], &ret);
  90           if (err)
  91             error (1, err, "pthread_join");
  92
  93           switch ((int) ret)
  94             {
  95             case 0:
  96               break;
  97
  98             case PTHREAD_BARRIER_SERIAL_THREAD:
  99               havesyncs++;
 100               break;
 101
 102             default:
 103               assert (!"Unknown value returned from pthread_barrier_wait.");
 104               break;
 105             }
 106         }
 107
 108       printf ("\n");
 109
 110       assert (havesyncs == 1);
 111     }
 112
 113   return 0;
 114 }