semaphore.h revision 219820 
1/*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice unmodified, this list of conditions, and the following
12 *    disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28#ifndef _LINUX_SEMAPHORE_H_
29#define _LINUX_SEMAPHORE_H_
30
31#include <sys/param.h>
32#include <sys/lock.h>
33#include <sys/sema.h>
34
35/*
36 * XXX BSD semaphores are disused and slow.  They also do not provide a
37 * sema_wait_sig method.  This must be resolved eventually.
38 */
39struct semaphore {
40	struct sema	sema;
41};
42
43#define	down(_sem)			sema_wait(&(_sem)->sema)
44#define	down_interruptible(_sem)	sema_wait(&(_sem)->sema), 0
45#define	down_trylock(_sem)		!sema_trywait(&(_sem)->sema)
46#define	up(_sem)			sema_post(&(_sem)->sema)
47
48static inline void
49linux_sema_init(struct semaphore *sem, int val)
50{
51
52	memset(&sem->sema, 0, sizeof(sem->sema));
53	sema_init(&sem->sema, val, "lnxsema");
54}
55
56static inline void
57init_MUTEX(struct semaphore *sem)
58{
59
60	memset(&sem->sema, 0, sizeof(sem->sema));
61	sema_init(&sem->sema, 1, "lnxsema");
62}
63
64#define	sema_init	linux_sema_init
65
66#endif /* _LINUX_SEMAPHORE_H_ */
67