/* 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 <errno.h>

#include <fcntl.h>

#include <semaphore.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

static void

remove_sem (int status, void *arg)

{

  sem_unlink (arg);

}

int

do_test (void)

{

  sem_t *s;

  sem_t *s2;

  pid_t pid;

  int val;

  /* Start with a clean slate and register a clean-up action.  No need to

     act if sem_unlink fails because we will catch the same problem during the

     sem_open below.  */

  sem_unlink ("/glibc-tst-sem4");

  on_exit (remove_sem, (void *) "/glibc-tst-sem4");

  s = sem_open ("/glibc-tst-sem4", O_CREAT, 0600, 1);

  if (s == SEM_FAILED)

    {

      if (errno == ENOSYS)

	{

	  puts ("sem_open not supported.  Oh well.");

	  return 0;

	}

      /* Maybe the shm filesystem has strict permissions.  */

      if (errno == EACCES)

	{

	  puts ("sem_open not allowed.  Oh well.");

	  return 0;

	}

      printf ("sem_open: %m\n");

      return 1;

    }

  /* We have the semaphore object.  Now try again with O_EXCL, this

     should fail.  */

  s2 = sem_open ("/glibc-tst-sem4", O_CREAT | O_EXCL, 0600, 1);

  if (s2 != SEM_FAILED)

    {

      puts ("2nd sem_open didn't fail");

      return 1;

    }

  if (errno != EEXIST)

    {

      puts ("2nd sem_open returned wrong error");

      return 1;

    }

  /* Check the value.  */

  if (sem_getvalue (s, &val) == -1)

    {

      puts ("getvalue failed");

      return 1;

    }

  if (val != 1)

    {

      printf ("initial value wrong: got %d, expected 1\n", val);

      return 1;

    }

  if (TEMP_FAILURE_RETRY (sem_wait (s)) == -1)

    {

      puts ("1st sem_wait failed");

      return 1;

    }

  pid = fork ();

  if (pid == -1)

    {

      printf ("fork failed: %m\n");

      return 1;

    }

  if (pid == 0)

    {

      /* Child.  */

      /* Check the value.  */

      if (sem_getvalue (s, &val) == -1)

	{

	  puts ("child: getvalue failed");

	  return 1;

	}

      if (val != 0)

	{

	  printf ("child: value wrong: got %d, expect 0\n", val);

	  return 1;

	}

      if (sem_post (s) == -1)

	{

	  puts ("child: post failed");

	  return 1;

	}

    }

  else

    {

      if (TEMP_FAILURE_RETRY (sem_wait (s)) == -1)

	{

	  puts ("2nd sem_wait failed");

	  return 1;

	}

      if (sem_getvalue (s, &val) == -1)

	{

	  puts ("parent: 2nd getvalue failed");

	  return 1;

	}

      if (val != 0)

	{

	  printf ("parent: value wrong: got %d, expected 0\n", val);

	  return 1;

	}

    }

  return 0;

}

#define TEST_FUNCTION do_test ()

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