1173444Sups/*-
2173444Sups * Copyright (c) 2007 Stephan Uphoff <ups@FreeBSD.org>
3173444Sups * All rights reserved.
4173444Sups *
5173444Sups * Redistribution and use in source and binary forms, with or without
6173444Sups * modification, are permitted provided that the following conditions
7173444Sups * are met:
8173444Sups * 1. Redistributions of source code must retain the above copyright
9173444Sups *    notice, this list of conditions and the following disclaimer.
10173444Sups * 2. Redistributions in binary form must reproduce the above copyright
11173444Sups *    notice, this list of conditions and the following disclaimer in the
12173444Sups *    documentation and/or other materials provided with the distribution.
13173444Sups * 3. Neither the name of the author nor the names of any co-contributors
14173444Sups *    may be used to endorse or promote products derived from this software
15173444Sups *    without specific prior written permission.
16173444Sups *
17173444Sups * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18173444Sups * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19173444Sups * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20173444Sups * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21173444Sups * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22173444Sups * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23173444Sups * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24173444Sups * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25173444Sups * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26173444Sups * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27173444Sups * SUCH DAMAGE.
28173444Sups *
29173444Sups * $FreeBSD$
30173444Sups */
31173444Sups
32173444Sups#ifndef _SYS__RMLOCK_H_
33173444Sups#define	_SYS__RMLOCK_H_
34173444Sups
35173444Sups/*
36173444Sups * Mostly reader/occasional writer lock.
37173444Sups */
38173444Sups
39173444SupsLIST_HEAD(rmpriolist,rm_priotracker);
40173444Sups
41240624Sattiliostruct rm_queue {
42240624Sattilio	struct rm_queue	*volatile rmq_next;
43240624Sattilio	struct rm_queue	*volatile rmq_prev;
44240624Sattilio};
45240624Sattilio
46173444Supsstruct rmlock {
47252209Sjhb	struct lock_object lock_object;
48222813Sattilio	volatile cpuset_t rm_writecpus;
49173444Sups	LIST_HEAD(,rm_priotracker) rm_activeReaders;
50212112Smlaier	union {
51252209Sjhb		struct lock_object _rm_wlock_object;
52212112Smlaier		struct mtx _rm_lock_mtx;
53212112Smlaier		struct sx _rm_lock_sx;
54212112Smlaier	} _rm_lock;
55173444Sups};
56252209Sjhb
57252209Sjhb#define	rm_wlock_object	_rm_lock._rm_wlock_object
58212112Smlaier#define	rm_lock_mtx	_rm_lock._rm_lock_mtx
59212112Smlaier#define	rm_lock_sx	_rm_lock._rm_lock_sx
60173444Sups
61173444Supsstruct rm_priotracker {
62173444Sups	struct rm_queue rmp_cpuQueue; /* Must be first */
63173444Sups	struct rmlock *rmp_rmlock;
64173444Sups	struct thread *rmp_thread;
65173444Sups	int rmp_flags;
66173444Sups	LIST_ENTRY(rm_priotracker) rmp_qentry;
67173444Sups};
68173444Sups
69173444Sups#endif /* !_SYS__RMLOCK_H_ */
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