1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 * $FreeBSD$
30 */
31
32#ifndef	_SYS_SEMA_H_
33#define	_SYS_SEMA_H_
34
35#include <sys/queue.h>
36#include <sys/_lock.h>
37#include <sys/_mutex.h>
38#include <sys/condvar.h>
39
40struct sema {
41	struct mtx	sema_mtx;	/* General protection lock. */
42	struct cv	sema_cv;	/* Waiters. */
43	int		sema_waiters;	/* Number of waiters. */
44	int		sema_value;	/* Semaphore value. */
45};
46
47#ifdef _KERNEL
48void	sema_init(struct sema *sema, int value, const char *description);
49void	sema_destroy(struct sema *sema);
50void	_sema_post(struct sema *sema, const char *file, int line);
51void	_sema_wait(struct sema *sema, const char *file, int line);
52int	_sema_timedwait(struct sema *sema, int timo, const char *file, int
53    line);
54int	_sema_trywait(struct sema *sema, const char *file, int line);
55int	sema_value(struct sema *sema);
56
57#define	sema_post(sema)		_sema_post((sema), LOCK_FILE, LOCK_LINE)
58#define	sema_wait(sema)		_sema_wait((sema), LOCK_FILE, LOCK_LINE)
59#define	sema_timedwait(sema, timo)					\
60	_sema_timedwait((sema), (timo), LOCK_FILE, LOCK_LINE)
61#define	sema_trywait(sema)	_sema_trywait((sema), LOCK_FILE, LOCK_LINE)
62
63#endif	/* _KERNEL */
64#endif	/* _SYS_SEMA_H_ */
65