1 // SPDX-License-Identifier: CDDL-1.0 2 /* 3 * CDDL HEADER START 4 * 5 * The contents of this file are subject to the terms of the 6 * Common Development and Distribution License (the "License"). 7 * You may not use this file except in compliance with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or https://opensource.org/licenses/CDDL-1.0. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2012, 2018 by Delphix. All rights reserved. 26 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 27 */ 28 29 #ifndef _SYS_RWLOCK_H 30 #define _SYS_RWLOCK_H 31 32 #include <pthread.h> 33 34 /* 35 * RW locks 36 */ 37 typedef struct krwlock { 38 pthread_rwlock_t rw_lock; 39 pthread_t rw_owner; 40 uint_t rw_readers; 41 } krwlock_t; 42 43 typedef int krw_t; 44 45 #define RW_READER 0 46 #define RW_WRITER 1 47 #define RW_DEFAULT RW_READER 48 #define RW_NOLOCKDEP RW_READER 49 50 #define RW_READ_HELD(rw) ((rw)->rw_readers > 0) 51 #define RW_WRITE_HELD(rw) pthread_equal((rw)->rw_owner, pthread_self()) 52 #define RW_LOCK_HELD(rw) (RW_READ_HELD(rw) || RW_WRITE_HELD(rw)) 53 54 extern void rw_init(krwlock_t *rwlp, char *name, int type, void *arg); 55 extern void rw_destroy(krwlock_t *rwlp); 56 extern void rw_enter(krwlock_t *rwlp, krw_t rw); 57 extern int rw_tryenter(krwlock_t *rwlp, krw_t rw); 58 extern int rw_tryupgrade(krwlock_t *rwlp); 59 extern void rw_exit(krwlock_t *rwlp); 60 #define rw_downgrade(rwlp) do { } while (0) 61 62 #endif /* _SYS_RWLOCK_H */ 63