1*7c478bd9Sstevel@tonic-gate /* 2*7c478bd9Sstevel@tonic-gate * CDDL HEADER START 3*7c478bd9Sstevel@tonic-gate * 4*7c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7c478bd9Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*7c478bd9Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*7c478bd9Sstevel@tonic-gate * with the License. 8*7c478bd9Sstevel@tonic-gate * 9*7c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*7c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*7c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 12*7c478bd9Sstevel@tonic-gate * and limitations under the License. 13*7c478bd9Sstevel@tonic-gate * 14*7c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*7c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*7c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*7c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*7c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*7c478bd9Sstevel@tonic-gate * 20*7c478bd9Sstevel@tonic-gate * CDDL HEADER END 21*7c478bd9Sstevel@tonic-gate */ 22*7c478bd9Sstevel@tonic-gate /* 23*7c478bd9Sstevel@tonic-gate * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24*7c478bd9Sstevel@tonic-gate * Use is subject to license terms. 25*7c478bd9Sstevel@tonic-gate */ 26*7c478bd9Sstevel@tonic-gate 27*7c478bd9Sstevel@tonic-gate #ifndef _SYS_RWSTLOCK_H 28*7c478bd9Sstevel@tonic-gate #define _SYS_RWSTLOCK_H 29*7c478bd9Sstevel@tonic-gate 30*7c478bd9Sstevel@tonic-gate /* 31*7c478bd9Sstevel@tonic-gate * Alternate rwlock that is interruptible and can be released by a thread 32*7c478bd9Sstevel@tonic-gate * other than the one that acquired the lock. 33*7c478bd9Sstevel@tonic-gate */ 34*7c478bd9Sstevel@tonic-gate 35*7c478bd9Sstevel@tonic-gate #ifdef __cplusplus 36*7c478bd9Sstevel@tonic-gate extern "C" { 37*7c478bd9Sstevel@tonic-gate #endif 38*7c478bd9Sstevel@tonic-gate 39*7c478bd9Sstevel@tonic-gate #include <sys/types.h> 40*7c478bd9Sstevel@tonic-gate #include <sys/ksynch.h> 41*7c478bd9Sstevel@tonic-gate #include <sys/rwlock.h> 42*7c478bd9Sstevel@tonic-gate 43*7c478bd9Sstevel@tonic-gate typedef struct rwstlock { 44*7c478bd9Sstevel@tonic-gate intptr_t rwst_count; 45*7c478bd9Sstevel@tonic-gate kcondvar_t rwst_rcv; 46*7c478bd9Sstevel@tonic-gate kcondvar_t rwst_wcv; 47*7c478bd9Sstevel@tonic-gate kmutex_t rwst_lock; 48*7c478bd9Sstevel@tonic-gate } rwstlock_t; 49*7c478bd9Sstevel@tonic-gate 50*7c478bd9Sstevel@tonic-gate /* 51*7c478bd9Sstevel@tonic-gate * The interfaces below are private to Sun Microsystems, 52*7c478bd9Sstevel@tonic-gate * and these might change without notice. 53*7c478bd9Sstevel@tonic-gate */ 54*7c478bd9Sstevel@tonic-gate 55*7c478bd9Sstevel@tonic-gate #define RWST_TRYENTER 0x01 56*7c478bd9Sstevel@tonic-gate #define RWST_SIG 0x02 57*7c478bd9Sstevel@tonic-gate 58*7c478bd9Sstevel@tonic-gate #define RWST_HELD(l) ((l)->rwst_count != 0) 59*7c478bd9Sstevel@tonic-gate #define RWST_READ_HELD(l) ((l)->rwst_count > 0) 60*7c478bd9Sstevel@tonic-gate #define RWST_WRITE_HELD(l) ((l)->rwst_count < 0) 61*7c478bd9Sstevel@tonic-gate #define RWST_WRITE_OWNER(l) \ 62*7c478bd9Sstevel@tonic-gate ((l)->rwst_count == (LONG_MIN | (intptr_t)curthread)) 63*7c478bd9Sstevel@tonic-gate #define RWST_OWNER(l) (RWST_WRITE_HELD(l) ? \ 64*7c478bd9Sstevel@tonic-gate ((struct _kthread *)((l)->rwst_count & ~LONG_MIN)) : NULL) 65*7c478bd9Sstevel@tonic-gate #define RWST_READ_WANTED(l) CV_HAS_WAITERS(&(l)->rwst_rcv) 66*7c478bd9Sstevel@tonic-gate #define RWST_WRITE_WANTED(l) CV_HAS_WAITERS(&(l)->rwst_wcv) 67*7c478bd9Sstevel@tonic-gate #define RWST_WAIT(cv, lock, f) \ 68*7c478bd9Sstevel@tonic-gate ((f) & RWST_SIG ? cv_wait_sig(cv, lock) : (cv_wait(cv, lock), 1)) 69*7c478bd9Sstevel@tonic-gate #define RWST_READ_WAIT(l, f) RWST_WAIT(&(l)->rwst_rcv, &(l)->rwst_lock, f) 70*7c478bd9Sstevel@tonic-gate #define RWST_WRITE_WAIT(l, f) RWST_WAIT(&(l)->rwst_wcv, &(l)->rwst_lock, f) 71*7c478bd9Sstevel@tonic-gate #define RWST_READ_WAKE_ALL(l) cv_broadcast(&(l)->rwst_rcv) 72*7c478bd9Sstevel@tonic-gate #define RWST_WRITE_WAKE_ONE(l) cv_signal(&(l)->rwst_wcv) 73*7c478bd9Sstevel@tonic-gate #define RWST_READ_ENTER(l) (l)->rwst_count++ 74*7c478bd9Sstevel@tonic-gate #define RWST_WRITE_ENTER(l) (l)->rwst_count = LONG_MIN | (intptr_t)curthread 75*7c478bd9Sstevel@tonic-gate #define RWST_READ_EXIT(l) (l)->rwst_count-- 76*7c478bd9Sstevel@tonic-gate #define RWST_WRITE_EXIT(l) (l)->rwst_count = 0 77*7c478bd9Sstevel@tonic-gate 78*7c478bd9Sstevel@tonic-gate extern void rwst_enter(rwstlock_t *, krw_t); 79*7c478bd9Sstevel@tonic-gate extern int rwst_enter_sig(rwstlock_t *, krw_t); 80*7c478bd9Sstevel@tonic-gate extern void rwst_exit(rwstlock_t *); 81*7c478bd9Sstevel@tonic-gate extern void rwst_init(rwstlock_t *, char *, krw_type_t, void *); 82*7c478bd9Sstevel@tonic-gate extern void rwst_destroy(rwstlock_t *); 83*7c478bd9Sstevel@tonic-gate extern int rwst_lock_held(rwstlock_t *, krw_t); 84*7c478bd9Sstevel@tonic-gate extern int rwst_tryenter(rwstlock_t *, krw_t); 85*7c478bd9Sstevel@tonic-gate extern struct _kthread *rwst_owner(rwstlock_t *); 86*7c478bd9Sstevel@tonic-gate 87*7c478bd9Sstevel@tonic-gate #ifdef __cplusplus 88*7c478bd9Sstevel@tonic-gate } 89*7c478bd9Sstevel@tonic-gate #endif 90*7c478bd9Sstevel@tonic-gate 91*7c478bd9Sstevel@tonic-gate #endif /* _SYS_RWSTLOCK_H */ 92