1/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _SEMAPHORE_H
20# error "Never use <bits/semaphore.h> directly; include <semaphore.h> instead."
21#endif
22
23#include <bits/wordsize.h>
24
25#if __WORDSIZE == 64
26# define __SIZEOF_SEM_T 32
27#else
28# define __SIZEOF_SEM_T 16
29#endif
30
31
32/* Value returned if `sem_open' failed. */
33#define SEM_FAILED ((sem_t *) 0)
34
35
36typedef union
37{
38 char __size[__SIZEOF_SEM_T];
39 long int __align;
40} sem_t;
41

source code of include/x86_64-linux-gnu/bits/semaphore.h