/* Test mutexes.

   Copyright (C) 2000-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   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/>.  */

#define _GNU_SOURCE

#include <pthread.h>

#include <assert.h>

#include <unistd.h>

#include <error.h>

#include <errno.h>

#include <stdio.h>

#define THREADS 500

void *

foo (void *arg)

{

  pthread_mutex_t *mutex = arg;

  pthread_mutex_lock (mutex);

  pthread_mutex_unlock (mutex);

  return mutex;

}

int

main (int argc, char **argv)

{

  int i;

  error_t err;

  pthread_t tid[THREADS];

  pthread_mutex_t mutex[THREADS];

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

    {

      pthread_mutex_init (&mutex[i], 0);

      pthread_mutex_lock (&mutex[i]);

      err = pthread_create (&tid[i], 0, foo, &mutex[i]);

      if (err)

	error (1, err, "pthread_create");

      sched_yield ();

    }

  for (i = THREADS - 1; i >= 0; i--)

    {

      void *ret;

      pthread_mutex_unlock (&mutex[i]);

      err = pthread_join (tid[i], &ret;;

      if (err)

	error (1, err, "pthread_join");

      assert (ret == &mutex[i]);

    }

  return 0;

}