1 1.5 riastrad /* $NetBSD: rwsem.h,v 1.5 2021/12/19 11:22:00 riastradh Exp $ */ 2 1.1 riastrad 3 1.1 riastrad /*- 4 1.1 riastrad * Copyright (c) 2014 The NetBSD Foundation, Inc. 5 1.1 riastrad * All rights reserved. 6 1.1 riastrad * 7 1.1 riastrad * This code is derived from software contributed to The NetBSD Foundation 8 1.1 riastrad * by Taylor R. Campbell. 9 1.1 riastrad * 10 1.1 riastrad * Redistribution and use in source and binary forms, with or without 11 1.1 riastrad * modification, are permitted provided that the following conditions 12 1.1 riastrad * are met: 13 1.1 riastrad * 1. Redistributions of source code must retain the above copyright 14 1.1 riastrad * notice, this list of conditions and the following disclaimer. 15 1.1 riastrad * 2. Redistributions in binary form must reproduce the above copyright 16 1.1 riastrad * notice, this list of conditions and the following disclaimer in the 17 1.1 riastrad * documentation and/or other materials provided with the distribution. 18 1.1 riastrad * 19 1.1 riastrad * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.1 riastrad * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.1 riastrad * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.1 riastrad * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.1 riastrad * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.1 riastrad * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.1 riastrad * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.1 riastrad * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.1 riastrad * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.1 riastrad * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.1 riastrad * POSSIBILITY OF SUCH DAMAGE. 30 1.1 riastrad */ 31 1.1 riastrad 32 1.1 riastrad /* 33 1.1 riastrad * These are not really semaphores; they are just reader/writer sleep 34 1.1 riastrad * locks, whereas what Linux calls an rwlock is a reader/writer spin 35 1.1 riastrad * lock. 36 1.1 riastrad * 37 1.1 riastrad * Notes on porting: 38 1.1 riastrad * 39 1.1 riastrad * - Linux does not have destroy_rwsem. You must add it yourself in 40 1.1 riastrad * the appropriate place. 41 1.1 riastrad */ 42 1.1 riastrad 43 1.1 riastrad #ifndef _LINUX_RWSEM_H_ 44 1.1 riastrad #define _LINUX_RWSEM_H_ 45 1.1 riastrad 46 1.1 riastrad #include <sys/mutex.h> 47 1.1 riastrad 48 1.3 riastrad #define destroy_rwsem linux_destroy_rwsem 49 1.3 riastrad #define down_read linux_down_read 50 1.3 riastrad #define down_read_trylock linux_down_read_trylock 51 1.3 riastrad #define down_write linux_down_write 52 1.3 riastrad #define downgrade_write linux_downgrade_write 53 1.3 riastrad #define init_rwsem linux_init_rwsem 54 1.3 riastrad #define up_read linux_up_read 55 1.3 riastrad #define up_write linux_up_write 56 1.3 riastrad 57 1.1 riastrad struct rw_semaphore { 58 1.5 riastrad /* 59 1.5 riastrad * Note: rws_lock and rws_cv must not be first; doing so 60 1.5 riastrad * confuses lockdebug. 61 1.5 riastrad */ 62 1.3 riastrad struct lwp *rws_writer; 63 1.3 riastrad unsigned rws_readers; 64 1.3 riastrad bool rws_writewanted; 65 1.4 riastrad bool rws_debug; 66 1.5 riastrad kmutex_t rws_lock; 67 1.5 riastrad kcondvar_t rws_cv; 68 1.1 riastrad }; 69 1.1 riastrad 70 1.3 riastrad void init_rwsem(struct rw_semaphore *); 71 1.3 riastrad void destroy_rwsem(struct rw_semaphore *); 72 1.3 riastrad void down_read(struct rw_semaphore *); 73 1.3 riastrad bool down_read_trylock(struct rw_semaphore *); 74 1.3 riastrad void down_write(struct rw_semaphore *); 75 1.3 riastrad void up_read(struct rw_semaphore *); 76 1.3 riastrad void up_write(struct rw_semaphore *); 77 1.3 riastrad void downgrade_write(struct rw_semaphore *); 78 1.2 riastrad 79 1.1 riastrad #endif /* _LINUX_RWSEM_H_ */ 80
Indexes created Sat Sep 20 22:09:52 GMT 2025