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 * $FreeBSD$ 32 */ 33 34 #ifndef _SYS__RMLOCK_H_ 35 #define _SYS__RMLOCK_H_ 36 37 /* 38 * Mostly reader/occasional writer lock. 39 */ 40 41 LIST_HEAD(rmpriolist,rm_priotracker); 42 43 struct rm_queue { 44 struct rm_queue *volatile rmq_next; 45 struct rm_queue *volatile rmq_prev; 46 }; 47 48 struct 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 63 struct 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 #include <sys/_mutex.h> 72 73 struct rmslock { 74 struct mtx mtx; 75 int writers; 76 int readers; 77 int *readers_pcpu; 78 int *readers_influx; 79 }; 80 81 #endif /* !_SYS__RMLOCK_H_ */ 82