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
32#ifndef _SYS__RMLOCK_H_
33#define _SYS__RMLOCK_H_
34
35#include <sys/_cpuset.h>
36#include <sys/_lock.h>
37#include <sys/_mutex.h>
38#include <sys/queue.h>
39#include <sys/_sx.h>
40
41struct thread;
42
43/*
44 * Mostly reader/occasional writer lock.
45 */
46
47LIST_HEAD(rmpriolist,rm_priotracker);
48
49struct rm_queue {
50 struct rm_queue *volatile rmq_next;
51 struct rm_queue *volatile rmq_prev;
52};
53
54struct rmlock {
55 struct lock_object lock_object;
56 volatile cpuset_t rm_writecpus;
57 LIST_HEAD(,rm_priotracker) rm_activeReaders;
58 union {
59 struct lock_object _rm_wlock_object;
60 struct mtx _rm_lock_mtx;
61 struct sx _rm_lock_sx;
62 } _rm_lock;
63};
64
65#define rm_wlock_object _rm_lock._rm_wlock_object
66#define rm_lock_mtx _rm_lock._rm_lock_mtx
67#define rm_lock_sx _rm_lock._rm_lock_sx
68
69struct rm_priotracker {
70 struct rm_queue rmp_cpuQueue; /* Must be first */
71 struct rmlock *rmp_rmlock;
72 struct thread *rmp_thread;
73 int rmp_flags;
74 LIST_ENTRY(rm_priotracker) rmp_qentry;
75};
76
77struct rmslock_pcpu;
78
79struct rmslock {
80 struct mtx mtx;
81 struct thread *owner;
82 struct rmslock_pcpu *pcpu;
83 int writers;
84 int readers;
85 int debug_readers;
86};
87
88#endif /* !_SYS__RMLOCK_H_ */