1/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
2   This file is part of the GNU C Library.
3
4   The GNU C Library is free software; you can redistribute it and/or
5   modify it under the terms of the GNU Lesser General Public
6   License as published by the Free Software Foundation; either
7   version 2.1 of the License, or (at your option) any later version.
8
9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library; if not, write to the Free
16   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17   02111-1307 USA.  */
18
19#ifndef _SEMAPHORE_H
20#define _SEMAPHORE_H	1
21
22#include <features.h>
23#include <sys/types.h>
24#ifdef __USE_XOPEN2K
25# define __need_timespec
26# include <time.h>
27#endif
28
29/* Get the definition for sem_t.  */
30#include <bits/semaphore.h>
31
32
33__BEGIN_DECLS
34
35/* Initialize semaphore object SEM to VALUE.  If PSHARED then share it
36   with other processes.  */
37extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value)
38     __THROW;
39/* Free resources associated with semaphore object SEM.  */
40extern int sem_destroy (sem_t *__sem) __THROW;
41
42/* Open a named semaphore NAME with open flags OFLAG.  */
43extern sem_t *sem_open (__const char *__name, int __oflag, ...) __THROW;
44
45/* Close descriptor for named semaphore SEM.  */
46extern int sem_close (sem_t *__sem) __THROW;
47
48/* Remove named semaphore NAME.  */
49extern int sem_unlink (__const char *__name) __THROW;
50
51/* Wait for SEM being posted.
52
53   This function is a cancellation point and therefore not marked with
54   __THROW.  */
55extern int sem_wait (sem_t *__sem);
56
57#ifdef __USE_XOPEN2K
58/* Similar to `sem_wait' but wait only until ABSTIME.
59
60   This function is a cancellation point and therefore not marked with
61   __THROW.  */
62extern int sem_timedwait (sem_t *__restrict __sem,
63			  __const struct timespec *__restrict __abstime);
64#endif
65
66/* Test whether SEM is posted.  */
67extern int sem_trywait (sem_t *__sem) __THROW;
68
69/* Post SEM.  */
70extern int sem_post (sem_t *__sem) __THROW;
71
72/* Get current value of SEM and store it in *SVAL.  */
73extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval)
74     __THROW;
75
76
77__END_DECLS
78
79#endif	/* semaphore.h */
80