/* 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 <unistd.h>

#include <sys/file.h>

static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;

static int fd;

static void *

tf (void *arg)

{

  if (flock (fd, LOCK_SH | LOCK_NB) != 0)

    {

      puts ("second flock failed");

      exit (1);

    }

  pthread_mutex_unlock (&lock);

  return NULL;

}

static int

do_test (void)

{

  char tmp[] = "/tmp/tst-flock1-XXXXXX";

  fd = mkstemp (tmp);

  if (fd == -1)

    {

      puts ("mkstemp failed");

      exit (1);

    }

  unlink (tmp);

  write (fd, "foobar xyzzy", 12);

  if (flock (fd, LOCK_EX | LOCK_NB) != 0)

    {

      puts ("first flock failed");

      exit (1);

    }

  pthread_mutex_lock (&lock);

  pthread_t th;

  if (pthread_create (&th, NULL, tf, NULL) != 0)

    {

      puts ("pthread_create failed");

      exit (1);

    }

  pthread_mutex_lock (&lock);

  void *result;

  if (pthread_join (th, &result) != 0)

    {

      puts ("pthread_join failed");

      exit (1);

    }

  close (fd);

  return result != NULL;

}

#define TEST_FUNCTION do_test ()

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