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/* Copyright (C) 2002-2021 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
<https://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"
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