1/* Copyright (C) 2002-2021 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 <https://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 __nonnull ((1));
37
38/* Free resources associated with semaphore object SEM. */
39extern int sem_destroy (sem_t *__sem) __THROW __nonnull ((1));
40
41/* Open a named semaphore NAME with open flags OFLAG. */
42extern sem_t *sem_open (const char *__name, int __oflag, ...)
43 __THROW __nonnull ((1));
44
45/* Close descriptor for named semaphore SEM. */
46extern int sem_close (sem_t *__sem) __THROW __nonnull ((1));
47
48/* Remove named semaphore NAME. */
49extern int sem_unlink (const char *__name) __THROW __nonnull ((1));
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) __nonnull ((1));
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 __nonnull ((1, 2));
65#endif
66
67#ifdef __USE_GNU
68extern int sem_clockwait (sem_t *__restrict __sem,
69 clockid_t clock,
70 const struct timespec *__restrict __abstime)
71 __nonnull ((1, 3));
72#endif
73
74/* Test whether SEM is posted. */
75extern int sem_trywait (sem_t *__sem) __THROWNL __nonnull ((1));
76
77/* Post SEM. */
78extern int sem_post (sem_t *__sem) __THROWNL __nonnull ((1));
79
80/* Get current value of SEM and store it in *SVAL. */
81extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval)
82 __THROW __nonnull ((1, 2));
83
84
85__END_DECLS
86
87#endif /* semaphore.h */
88