17c478bdstevel@tonic-gate/*
27c478bdstevel@tonic-gate * CDDL HEADER START
37c478bdstevel@tonic-gate *
47c478bdstevel@tonic-gate * The contents of this file are subject to the terms of the
5374ae87svemuri * Common Development and Distribution License (the "License").
6374ae87svemuri * You may not use this file except in compliance with the License.
77c478bdstevel@tonic-gate *
87c478bdstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bdstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
107c478bdstevel@tonic-gate * See the License for the specific language governing permissions
117c478bdstevel@tonic-gate * and limitations under the License.
127c478bdstevel@tonic-gate *
137c478bdstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
147c478bdstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bdstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
167c478bdstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
177c478bdstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bdstevel@tonic-gate *
197c478bdstevel@tonic-gate * CDDL HEADER END
207c478bdstevel@tonic-gate */
217c478bdstevel@tonic-gate/*
22374ae87svemuri * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23374ae87svemuri * Use is subject to license terms.
247c478bdstevel@tonic-gate */
257c478bdstevel@tonic-gate
26b3d32f0Bryan Cantrill/*
27b3d32f0Bryan Cantrill * Copyright (c) 2013, Joyent, Inc.  All rights reserved.
28b3d32f0Bryan Cantrill */
29b3d32f0Bryan Cantrill
307c478bdstevel@tonic-gate#ifndef _SYS_RWLOCK_H
317c478bdstevel@tonic-gate#define	_SYS_RWLOCK_H
327c478bdstevel@tonic-gate
337c478bdstevel@tonic-gate/*
347c478bdstevel@tonic-gate * Public interface to readers/writer locks.  See rwlock(9F) for details.
357c478bdstevel@tonic-gate */
367c478bdstevel@tonic-gate
377c478bdstevel@tonic-gate#include <sys/types.h>
387c478bdstevel@tonic-gate
397c478bdstevel@tonic-gate#ifdef	__cplusplus
407c478bdstevel@tonic-gateextern "C" {
417c478bdstevel@tonic-gate#endif
427c478bdstevel@tonic-gate
437c478bdstevel@tonic-gate#ifndef _ASM
447c478bdstevel@tonic-gate
457c478bdstevel@tonic-gatetypedef enum {
467c478bdstevel@tonic-gate	RW_DRIVER = 2,		/* driver (DDI) rwlock */
477c478bdstevel@tonic-gate	RW_DEFAULT = 4		/* kernel default rwlock */
487c478bdstevel@tonic-gate} krw_type_t;
497c478bdstevel@tonic-gate
507c478bdstevel@tonic-gatetypedef enum {
517c478bdstevel@tonic-gate	RW_WRITER,
52b3d32f0Bryan Cantrill	RW_READER,
53b3d32f0Bryan Cantrill	RW_READER_STARVEWRITER
547c478bdstevel@tonic-gate} krw_t;
557c478bdstevel@tonic-gate
567c478bdstevel@tonic-gatetypedef struct _krwlock {
577c478bdstevel@tonic-gate	void	*_opaque[1];
587c478bdstevel@tonic-gate} krwlock_t;
597c478bdstevel@tonic-gate
607c478bdstevel@tonic-gate#if defined(_KERNEL)
617c478bdstevel@tonic-gate
627c478bdstevel@tonic-gate#define	RW_READ_HELD(x)		(rw_read_held((x)))
637c478bdstevel@tonic-gate#define	RW_WRITE_HELD(x)	(rw_write_held((x)))
647c478bdstevel@tonic-gate#define	RW_LOCK_HELD(x)		(rw_lock_held((x)))
657c478bdstevel@tonic-gate#define	RW_ISWRITER(x)		(rw_iswriter(x))
667c478bdstevel@tonic-gate
677c478bdstevel@tonic-gateextern	void	rw_init(krwlock_t *, char *, krw_type_t, void *);
687c478bdstevel@tonic-gateextern	void	rw_destroy(krwlock_t *);
697c478bdstevel@tonic-gateextern	void	rw_enter(krwlock_t *, krw_t);
707c478bdstevel@tonic-gateextern	int	rw_tryenter(krwlock_t *, krw_t);
717c478bdstevel@tonic-gateextern	void	rw_exit(krwlock_t *);
727c478bdstevel@tonic-gateextern	void	rw_downgrade(krwlock_t *);
737c478bdstevel@tonic-gateextern	int	rw_tryupgrade(krwlock_t *);
747c478bdstevel@tonic-gateextern	int	rw_read_held(krwlock_t *);
757c478bdstevel@tonic-gateextern	int	rw_write_held(krwlock_t *);
767c478bdstevel@tonic-gateextern	int	rw_lock_held(krwlock_t *);
777c478bdstevel@tonic-gateextern	int	rw_read_locked(krwlock_t *);
787c478bdstevel@tonic-gateextern	int	rw_iswriter(krwlock_t *);
797c478bdstevel@tonic-gateextern	struct _kthread *rw_owner(krwlock_t *);
80374ae87svemuriextern	uint_t (*rw_lock_backoff)(uint_t);
81374ae87svemuriextern	void (*rw_lock_delay)(uint_t);
827c478bdstevel@tonic-gate
837c478bdstevel@tonic-gate#endif	/* defined(_KERNEL) */
847c478bdstevel@tonic-gate
857c478bdstevel@tonic-gate#endif	/* _ASM */
867c478bdstevel@tonic-gate
877c478bdstevel@tonic-gate#ifdef	__cplusplus
887c478bdstevel@tonic-gate}
897c478bdstevel@tonic-gate#endif
907c478bdstevel@tonic-gate
917c478bdstevel@tonic-gate#endif	/* _SYS_RWLOCK_H */
92