1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 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 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #ifndef _SYS_RWSTLOCK_H 28 #define _SYS_RWSTLOCK_H 29 30 /* 31 * Alternate rwlock that is interruptible and can be released by a thread 32 * other than the one that acquired the lock. 33 */ 34 35 #ifdef __cplusplus 36 extern "C" { 37 #endif 38 39 #include <sys/types.h> 40 #include <sys/ksynch.h> 41 #include <sys/rwlock.h> 42 43 typedef struct rwstlock { 44 intptr_t rwst_count; 45 kcondvar_t rwst_rcv; 46 kcondvar_t rwst_wcv; 47 kmutex_t rwst_lock; 48 } rwstlock_t; 49 50 /* 51 * The interfaces below are private to Sun Microsystems, 52 * and these might change without notice. 53 */ 54 55 #define RWST_TRYENTER 0x01 56 #define RWST_SIG 0x02 57 58 #define RWST_HELD(l) ((l)->rwst_count != 0) 59 #define RWST_READ_HELD(l) ((l)->rwst_count > 0) 60 #define RWST_WRITE_HELD(l) ((l)->rwst_count < 0) 61 #define RWST_WRITE_OWNER(l) \ 62 ((l)->rwst_count == (LONG_MIN | (intptr_t)curthread)) 63 #define RWST_OWNER(l) (RWST_WRITE_HELD(l) ? \ 64 ((struct _kthread *)((l)->rwst_count & ~LONG_MIN)) : NULL) 65 #define RWST_READ_WANTED(l) CV_HAS_WAITERS(&(l)->rwst_rcv) 66 #define RWST_WRITE_WANTED(l) CV_HAS_WAITERS(&(l)->rwst_wcv) 67 #define RWST_WAIT(cv, lock, f) \ 68 ((f) & RWST_SIG ? cv_wait_sig(cv, lock) : (cv_wait(cv, lock), 1)) 69 #define RWST_READ_WAIT(l, f) RWST_WAIT(&(l)->rwst_rcv, &(l)->rwst_lock, f) 70 #define RWST_WRITE_WAIT(l, f) RWST_WAIT(&(l)->rwst_wcv, &(l)->rwst_lock, f) 71 #define RWST_READ_WAKE_ALL(l) cv_broadcast(&(l)->rwst_rcv) 72 #define RWST_WRITE_WAKE_ONE(l) cv_signal(&(l)->rwst_wcv) 73 #define RWST_READ_ENTER(l) (l)->rwst_count++ 74 #define RWST_WRITE_ENTER(l) (l)->rwst_count = LONG_MIN | (intptr_t)curthread 75 #define RWST_READ_EXIT(l) (l)->rwst_count-- 76 #define RWST_WRITE_EXIT(l) (l)->rwst_count = 0 77 78 extern void rwst_enter(rwstlock_t *, krw_t); 79 extern int rwst_enter_sig(rwstlock_t *, krw_t); 80 extern void rwst_exit(rwstlock_t *); 81 extern void rwst_init(rwstlock_t *, char *, krw_type_t, void *); 82 extern void rwst_destroy(rwstlock_t *); 83 extern int rwst_lock_held(rwstlock_t *, krw_t); 84 extern int rwst_tryenter(rwstlock_t *, krw_t); 85 extern struct _kthread *rwst_owner(rwstlock_t *); 86 87 #ifdef __cplusplus 88 } 89 #endif 90 91 #endif /* _SYS_RWSTLOCK_H */ 92