xref: /illumos-gate/usr/src/uts/common/sys/rwlock.h (revision b3d32f0c)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5374ae87fSsvemuri  * Common Development and Distribution License (the "License").
6374ae87fSsvemuri  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
217c478bd9Sstevel@tonic-gate /*
22374ae87fSsvemuri  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23374ae87fSsvemuri  * Use is subject to license terms.
247c478bd9Sstevel@tonic-gate  */
257c478bd9Sstevel@tonic-gate 
26*b3d32f0cSBryan Cantrill /*
27*b3d32f0cSBryan Cantrill  * Copyright (c) 2013, Joyent, Inc.  All rights reserved.
28*b3d32f0cSBryan Cantrill  */
29*b3d32f0cSBryan Cantrill 
307c478bd9Sstevel@tonic-gate #ifndef _SYS_RWLOCK_H
317c478bd9Sstevel@tonic-gate #define	_SYS_RWLOCK_H
327c478bd9Sstevel@tonic-gate 
337c478bd9Sstevel@tonic-gate /*
347c478bd9Sstevel@tonic-gate  * Public interface to readers/writer locks.  See rwlock(9F) for details.
357c478bd9Sstevel@tonic-gate  */
367c478bd9Sstevel@tonic-gate 
377c478bd9Sstevel@tonic-gate #include <sys/types.h>
387c478bd9Sstevel@tonic-gate 
397c478bd9Sstevel@tonic-gate #ifdef	__cplusplus
407c478bd9Sstevel@tonic-gate extern "C" {
417c478bd9Sstevel@tonic-gate #endif
427c478bd9Sstevel@tonic-gate 
437c478bd9Sstevel@tonic-gate #ifndef _ASM
447c478bd9Sstevel@tonic-gate 
457c478bd9Sstevel@tonic-gate typedef enum {
467c478bd9Sstevel@tonic-gate 	RW_DRIVER = 2,		/* driver (DDI) rwlock */
477c478bd9Sstevel@tonic-gate 	RW_DEFAULT = 4		/* kernel default rwlock */
487c478bd9Sstevel@tonic-gate } krw_type_t;
497c478bd9Sstevel@tonic-gate 
507c478bd9Sstevel@tonic-gate typedef enum {
517c478bd9Sstevel@tonic-gate 	RW_WRITER,
52*b3d32f0cSBryan Cantrill 	RW_READER,
53*b3d32f0cSBryan Cantrill 	RW_READER_STARVEWRITER
547c478bd9Sstevel@tonic-gate } krw_t;
557c478bd9Sstevel@tonic-gate 
567c478bd9Sstevel@tonic-gate typedef struct _krwlock {
577c478bd9Sstevel@tonic-gate 	void	*_opaque[1];
587c478bd9Sstevel@tonic-gate } krwlock_t;
597c478bd9Sstevel@tonic-gate 
607c478bd9Sstevel@tonic-gate #if defined(_KERNEL)
617c478bd9Sstevel@tonic-gate 
627c478bd9Sstevel@tonic-gate #define	RW_READ_HELD(x)		(rw_read_held((x)))
637c478bd9Sstevel@tonic-gate #define	RW_WRITE_HELD(x)	(rw_write_held((x)))
647c478bd9Sstevel@tonic-gate #define	RW_LOCK_HELD(x)		(rw_lock_held((x)))
657c478bd9Sstevel@tonic-gate #define	RW_ISWRITER(x)		(rw_iswriter(x))
667c478bd9Sstevel@tonic-gate 
677c478bd9Sstevel@tonic-gate extern	void	rw_init(krwlock_t *, char *, krw_type_t, void *);
687c478bd9Sstevel@tonic-gate extern	void	rw_destroy(krwlock_t *);
697c478bd9Sstevel@tonic-gate extern	void	rw_enter(krwlock_t *, krw_t);
707c478bd9Sstevel@tonic-gate extern	int	rw_tryenter(krwlock_t *, krw_t);
717c478bd9Sstevel@tonic-gate extern	void	rw_exit(krwlock_t *);
727c478bd9Sstevel@tonic-gate extern	void	rw_downgrade(krwlock_t *);
737c478bd9Sstevel@tonic-gate extern	int	rw_tryupgrade(krwlock_t *);
747c478bd9Sstevel@tonic-gate extern	int	rw_read_held(krwlock_t *);
757c478bd9Sstevel@tonic-gate extern	int	rw_write_held(krwlock_t *);
767c478bd9Sstevel@tonic-gate extern	int	rw_lock_held(krwlock_t *);
777c478bd9Sstevel@tonic-gate extern	int	rw_read_locked(krwlock_t *);
787c478bd9Sstevel@tonic-gate extern	int	rw_iswriter(krwlock_t *);
797c478bd9Sstevel@tonic-gate extern	struct _kthread *rw_owner(krwlock_t *);
80374ae87fSsvemuri extern	uint_t (*rw_lock_backoff)(uint_t);
81374ae87fSsvemuri extern	void (*rw_lock_delay)(uint_t);
827c478bd9Sstevel@tonic-gate 
837c478bd9Sstevel@tonic-gate #endif	/* defined(_KERNEL) */
847c478bd9Sstevel@tonic-gate 
857c478bd9Sstevel@tonic-gate #endif	/* _ASM */
867c478bd9Sstevel@tonic-gate 
877c478bd9Sstevel@tonic-gate #ifdef	__cplusplus
887c478bd9Sstevel@tonic-gate }
897c478bd9Sstevel@tonic-gate #endif
907c478bd9Sstevel@tonic-gate 
917c478bd9Sstevel@tonic-gate #endif	/* _SYS_RWLOCK_H */
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