1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (C) 2001 Jason Evans <jasone@freebsd.org>. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice(s), this list of conditions and the following disclaimer as
11 * the first lines of this file unmodified other than the possible
12 * addition of one or more copyright notices.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice(s), this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
27 * DAMAGE.
28 */
29
30#ifndef _SYS_SEMA_H_
31#define _SYS_SEMA_H_
32
33#include <sys/queue.h>
34#include <sys/_lock.h>
35#include <sys/_mutex.h>
36#include <sys/condvar.h>
37
38struct sema {
39 struct mtx sema_mtx; /* General protection lock. */
40 struct cv sema_cv; /* Waiters. */
41 int sema_waiters; /* Number of waiters. */
42 int sema_value; /* Semaphore value. */
43};
44
45#ifdef _KERNEL
46void sema_init(struct sema *sema, int value, const char *description);
47void sema_destroy(struct sema *sema);
48void _sema_post(struct sema *sema, const char *file, int line);
49void _sema_wait(struct sema *sema, const char *file, int line);
50int _sema_timedwait(struct sema *sema, int timo, const char *file, int
51 line);
52int _sema_trywait(struct sema *sema, const char *file, int line);
53int sema_value(struct sema *sema);
54
55#define sema_post(sema) _sema_post((sema), LOCK_FILE, LOCK_LINE)
56#define sema_wait(sema) _sema_wait((sema), LOCK_FILE, LOCK_LINE)
57#define sema_timedwait(sema, timo) \
58 _sema_timedwait((sema), (timo), LOCK_FILE, LOCK_LINE)
59#define sema_trywait(sema) _sema_trywait((sema), LOCK_FILE, LOCK_LINE)
60
61#endif /* _KERNEL */
62#endif /* _SYS_SEMA_H_ */