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_ */
63