1/* Copyright (C) 2002-2019 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, see
16 <http://www.gnu.org/licenses/>. */
17
18#ifndef _SEMAPHORE_H
19#define _SEMAPHORE_H 1
20
21#include <features.h>
22#include <sys/types.h>
23#ifdef __USE_XOPEN2K
24# include <bits/types/struct_timespec.h>
25#endif
26
27/* Get the definition for sem_t. */
28#include <bits/semaphore.h>
29
30
31__BEGIN_DECLS
32
33/* Initialize semaphore object SEM to VALUE. If PSHARED then share it
34 with other processes. */
35extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value)
36 __THROW;
37/* Free resources associated with semaphore object SEM. */
38extern int sem_destroy (sem_t *__sem) __THROW;
39
40/* Open a named semaphore NAME with open flags OFLAG. */
41extern sem_t *sem_open (const char *__name, int __oflag, ...) __THROW;
42
43/* Close descriptor for named semaphore SEM. */
44extern int sem_close (sem_t *__sem) __THROW;
45
46/* Remove named semaphore NAME. */
47extern int sem_unlink (const char *__name) __THROW;
48
49/* Wait for SEM being posted.
50
51 This function is a cancellation point and therefore not marked with
52 __THROW. */
53extern int sem_wait (sem_t *__sem);
54
55#ifdef __USE_XOPEN2K
56/* Similar to `sem_wait' but wait only until ABSTIME.
57
58 This function is a cancellation point and therefore not marked with
59 __THROW. */
60extern int sem_timedwait (sem_t *__restrict __sem,
61 const struct timespec *__restrict __abstime);
62#endif
63
64/* Test whether SEM is posted. */
65extern int sem_trywait (sem_t *__sem) __THROWNL;
66
67/* Post SEM. */
68extern int sem_post (sem_t *__sem) __THROWNL;
69
70/* Get current value of SEM and store it in *SVAL. */
71extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval)
72 __THROW;
73
74
75__END_DECLS
76
77#endif /* semaphore.h */
78