nptl/tst-barrier3.c

   1 /* Test of POSIX barriers.
   2    Copyright (C) 2002-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <pthread.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #define NTHREADS 20
  26
  27 #define ROUNDS 20
  28
  29 static pthread_barrier_t barriers[NTHREADS];
  30
  31 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
  32 static int counters[NTHREADS];
  33 static int serial[NTHREADS];
  34
  35 static void *
  36 worker (void *arg)
  37 {
  38   void *result = NULL;
  39   int nr = (long int) arg;
  40   int i;
  41
  42   for (i = 0; i < ROUNDS; ++i)
  43     {
  44       int j;
  45       int retval;
  46
  47       if (nr == 0)
  48         {
  49           memset (counters, '\0', sizeof (counters));
  50           memset (serial, '\0', sizeof (serial));
  51         }
  52
  53       retval = pthread_barrier_wait (&barriers[NTHREADS - 1]);
  54       if (retval != 0 && retval != PTHREAD_BARRIER_SERIAL_THREAD)
  55         {
  56           printf ("thread %d failed to wait for all the others\n", nr);
  57           result = (void *) 1;
  58         }
  59
  60       for (j = nr; j < NTHREADS; ++j)
  61         {
  62           /* Increment the counter for this round.  */
  63           pthread_mutex_lock (&lock);
  64           ++counters[j];
  65           pthread_mutex_unlock (&lock);
  66
  67           /* Wait for the rest.  */
  68           retval = pthread_barrier_wait (&barriers[j]);
  69
  70           /* Test the result.  */
  71           if (nr == 0 && counters[j] != j + 1)
  72             {
  73               printf ("barrier in round %d released but count is %d\n",
  74                       j, counters[j]);
  75               result = (void *) 1;
  76             }
  77
  78           if (retval != 0)
  79             {
  80               if (retval != PTHREAD_BARRIER_SERIAL_THREAD)
  81                 {
  82                   printf ("thread %d in round %d has nonzero return value != PTHREAD_BARRIER_SERIAL_THREAD\n",
  83                           nr, j);
  84                   result = (void *) 1;
  85                 }
  86               else
  87                 {
  88                   pthread_mutex_lock (&lock);
  89                   ++serial[j];
  90                   pthread_mutex_unlock (&lock);
  91                 }
  92             }
  93
  94           /* Wait for the rest again.  */
  95           retval = pthread_barrier_wait (&barriers[j]);
  96
  97           /* Now we can check whether exactly one thread was serializing.  */
  98           if (nr == 0 && serial[j] != 1)
  99             {
 100               printf ("not exactly one serial thread in round %d\n", j);
 101               result = (void *) 1;
 102             }
 103         }
 104     }
 105
 106   return result;
 107 }
 108
 109
 110 #define TEST_FUNCTION do_test ()
 111 #define TIMEOUT 60
 112 static int
 113 do_test (void)
 114 {
 115   pthread_t threads[NTHREADS];
 116   int i;
 117   void *res;
 118   int result = 0;
 119
 120   /* Initialized the barrier variables.  */
 121   for (i = 0; i < NTHREADS; ++i)
 122     if (pthread_barrier_init (&barriers[i], NULL, i + 1) != 0)
 123       {
 124         printf ("Failed to initialize barrier %d\n", i);
 125         exit (1);
 126       }
 127
 128   /* Start the threads.  */
 129   for (i = 0; i < NTHREADS; ++i)
 130     if (pthread_create (&threads[i], NULL, worker, (void *) (long int) i) != 0)
 131       {
 132         printf ("Failed to start thread %d\n", i);
 133         exit (1);
 134       }
 135
 136   /* And wait for them.  */
 137   for (i = 0; i < NTHREADS; ++i)
 138     if (pthread_join (threads[i], &res) != 0 || res != NULL)
 139       {
 140         printf ("thread %d returned a failure\n", i);
 141         result = 1;
 142       }
 143     else
 144       printf ("joined threads %d\n", i);
 145
 146   if (result == 0)
 147     puts ("all OK");
 148
 149   return result;
 150 }
 151
 152 #include "../test-skeleton.c"