_rmlock.h revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2007 Stephan Uphoff <ups@FreeBSD.org>
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, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the author nor the names of any co-contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $FreeBSD: stable/11/sys/sys/_rmlock.h 330897 2018-03-14 03:19:51Z eadler $
32 */
33
34#ifndef _SYS__RMLOCK_H_
35#define	_SYS__RMLOCK_H_
36
37/*
38 * Mostly reader/occasional writer lock.
39 */
40
41LIST_HEAD(rmpriolist,rm_priotracker);
42
43struct rm_queue {
44	struct rm_queue	*volatile rmq_next;
45	struct rm_queue	*volatile rmq_prev;
46};
47
48struct rmlock {
49	struct lock_object lock_object;
50	volatile cpuset_t rm_writecpus;
51	LIST_HEAD(,rm_priotracker) rm_activeReaders;
52	union {
53		struct lock_object _rm_wlock_object;
54		struct mtx _rm_lock_mtx;
55		struct sx _rm_lock_sx;
56	} _rm_lock;
57};
58
59#define	rm_wlock_object	_rm_lock._rm_wlock_object
60#define	rm_lock_mtx	_rm_lock._rm_lock_mtx
61#define	rm_lock_sx	_rm_lock._rm_lock_sx
62
63struct rm_priotracker {
64	struct rm_queue rmp_cpuQueue; /* Must be first */
65	struct rmlock *rmp_rmlock;
66	struct thread *rmp_thread;
67	int rmp_flags;
68	LIST_ENTRY(rm_priotracker) rmp_qentry;
69};
70
71#endif /* !_SYS__RMLOCK_H_ */
72