1/*-
2 * Copyright (C) 2001 Jason Evans <jasone@freebsd.org>.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice(s), this list of conditions and the following disclaimer as
9 *    the first lines of this file unmodified other than the possible
10 *    addition of one or more copyright notices.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice(s), this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
25 * DAMAGE.
26 *
27 * $FreeBSD$
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