/* Test of POSIX barriers.

   Copyright (C) 2002-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <pthread.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#define NTHREADS 20

#define ROUNDS 20

static pthread_barrier_t barriers[NTHREADS];

static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;

static int counters[NTHREADS];

static int serial[NTHREADS];

static void *

worker (void *arg)

{

  void *result = NULL;

  int nr = (long int) arg;

  int i;

  for (i = 0; i < ROUNDS; ++i)

    {

      int j;

      int retval;

      if (nr == 0)

	{

	  memset (counters, '\0', sizeof (counters));

	  memset (serial, '\0', sizeof (serial));

	}

      retval = pthread_barrier_wait (&barriers[NTHREADS - 1]);

      if (retval != 0 && retval != PTHREAD_BARRIER_SERIAL_THREAD)

	{

	  printf ("thread %d failed to wait for all the others\n", nr);

	  result = (void *) 1;

	}

      for (j = nr; j < NTHREADS; ++j)

	{

	  /* Increment the counter for this round.  */

	  pthread_mutex_lock (&lock);

	  ++counters[j];

	  pthread_mutex_unlock (&lock);

	  /* Wait for the rest.  */

	  retval = pthread_barrier_wait (&barriers[j]);

	  /* Test the result.  */

	  if (nr == 0 && counters[j] != j + 1)

	    {

	      printf ("barrier in round %d released but count is %d\n",

		      j, counters[j]);

	      result = (void *) 1;

	    }

	  if (retval != 0)

	    {

	      if (retval != PTHREAD_BARRIER_SERIAL_THREAD)

		{

		  printf ("thread %d in round %d has nonzero return value != PTHREAD_BARRIER_SERIAL_THREAD\n",

			  nr, j);

		  result = (void *) 1;

		}

	      else

		{

		  pthread_mutex_lock (&lock);

		  ++serial[j];

		  pthread_mutex_unlock (&lock);

		}

	    }

	  /* Wait for the rest again.  */

	  retval = pthread_barrier_wait (&barriers[j]);

	  /* Now we can check whether exactly one thread was serializing.  */

	  if (nr == 0 && serial[j] != 1)

	    {

	      printf ("not exactly one serial thread in round %d\n", j);

	      result = (void *) 1;

	    }

	}

    }

  return result;

}

#define TEST_FUNCTION do_test ()

#define TIMEOUT 60

static int

do_test (void)

{

  pthread_t threads[NTHREADS];

  int i;

  void *res;

  int result = 0;

  /* Initialized the barrier variables.  */

  for (i = 0; i < NTHREADS; ++i)

    if (pthread_barrier_init (&barriers[i], NULL, i + 1) != 0)

      {

	printf ("Failed to initialize barrier %d\n", i);

	exit (1);

      }

  /* Start the threads.  */

  for (i = 0; i < NTHREADS; ++i)

    if (pthread_create (&threads[i], NULL, worker, (void *) (long int) i) != 0)

      {

	printf ("Failed to start thread %d\n", i);

	exit (1);

      }

  /* And wait for them.  */

  for (i = 0; i < NTHREADS; ++i)

    if (pthread_join (threads[i], &res) != 0 || res != NULL)

      {

	printf ("thread %d returned a failure\n", i);

	result = 1;

      }

    else

      printf ("joined threads %d\n", i);

  if (result == 0)

    puts ("all OK");

  return result;

}

#include "../test-skeleton.c"