xref: /onnv-gate/usr/src/uts/common/sys/rwlock.h (revision 6138:1b7a278742d4)
10Sstevel@tonic-gate /*
20Sstevel@tonic-gate  * CDDL HEADER START
30Sstevel@tonic-gate  *
40Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*6138Ssvemuri  * Common Development and Distribution License (the "License").
6*6138Ssvemuri  * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate  *
80Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate  * See the License for the specific language governing permissions
110Sstevel@tonic-gate  * and limitations under the License.
120Sstevel@tonic-gate  *
130Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate  *
190Sstevel@tonic-gate  * CDDL HEADER END
200Sstevel@tonic-gate  */
210Sstevel@tonic-gate /*
22*6138Ssvemuri  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23*6138Ssvemuri  * Use is subject to license terms.
240Sstevel@tonic-gate  */
250Sstevel@tonic-gate 
260Sstevel@tonic-gate #ifndef _SYS_RWLOCK_H
270Sstevel@tonic-gate #define	_SYS_RWLOCK_H
280Sstevel@tonic-gate 
290Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
300Sstevel@tonic-gate 
310Sstevel@tonic-gate /*
320Sstevel@tonic-gate  * Public interface to readers/writer locks.  See rwlock(9F) for details.
330Sstevel@tonic-gate  */
340Sstevel@tonic-gate 
350Sstevel@tonic-gate #include <sys/types.h>
360Sstevel@tonic-gate 
370Sstevel@tonic-gate #ifdef	__cplusplus
380Sstevel@tonic-gate extern "C" {
390Sstevel@tonic-gate #endif
400Sstevel@tonic-gate 
410Sstevel@tonic-gate #ifndef _ASM
420Sstevel@tonic-gate 
430Sstevel@tonic-gate typedef enum {
440Sstevel@tonic-gate 	RW_DRIVER = 2,		/* driver (DDI) rwlock */
450Sstevel@tonic-gate 	RW_DEFAULT = 4		/* kernel default rwlock */
460Sstevel@tonic-gate } krw_type_t;
470Sstevel@tonic-gate 
480Sstevel@tonic-gate typedef enum {
490Sstevel@tonic-gate 	RW_WRITER,
500Sstevel@tonic-gate 	RW_READER
510Sstevel@tonic-gate } krw_t;
520Sstevel@tonic-gate 
530Sstevel@tonic-gate typedef struct _krwlock {
540Sstevel@tonic-gate 	void	*_opaque[1];
550Sstevel@tonic-gate } krwlock_t;
560Sstevel@tonic-gate 
570Sstevel@tonic-gate #if defined(_KERNEL)
580Sstevel@tonic-gate 
590Sstevel@tonic-gate #define	RW_READ_HELD(x)		(rw_read_held((x)))
600Sstevel@tonic-gate #define	RW_WRITE_HELD(x)	(rw_write_held((x)))
610Sstevel@tonic-gate #define	RW_LOCK_HELD(x)		(rw_lock_held((x)))
620Sstevel@tonic-gate #define	RW_ISWRITER(x)		(rw_iswriter(x))
630Sstevel@tonic-gate 
640Sstevel@tonic-gate extern	void	rw_init(krwlock_t *, char *, krw_type_t, void *);
650Sstevel@tonic-gate extern	void	rw_destroy(krwlock_t *);
660Sstevel@tonic-gate extern	void	rw_enter(krwlock_t *, krw_t);
670Sstevel@tonic-gate extern	int	rw_tryenter(krwlock_t *, krw_t);
680Sstevel@tonic-gate extern	void	rw_exit(krwlock_t *);
690Sstevel@tonic-gate extern	void	rw_downgrade(krwlock_t *);
700Sstevel@tonic-gate extern	int	rw_tryupgrade(krwlock_t *);
710Sstevel@tonic-gate extern	int	rw_read_held(krwlock_t *);
720Sstevel@tonic-gate extern	int	rw_write_held(krwlock_t *);
730Sstevel@tonic-gate extern	int	rw_lock_held(krwlock_t *);
740Sstevel@tonic-gate extern	int	rw_read_locked(krwlock_t *);
750Sstevel@tonic-gate extern	int	rw_iswriter(krwlock_t *);
760Sstevel@tonic-gate extern	struct _kthread *rw_owner(krwlock_t *);
77*6138Ssvemuri extern	uint_t (*rw_lock_backoff)(uint_t);
78*6138Ssvemuri extern	void (*rw_lock_delay)(uint_t);
790Sstevel@tonic-gate 
800Sstevel@tonic-gate #endif	/* defined(_KERNEL) */
810Sstevel@tonic-gate 
820Sstevel@tonic-gate #endif	/* _ASM */
830Sstevel@tonic-gate 
840Sstevel@tonic-gate #ifdef	__cplusplus
850Sstevel@tonic-gate }
860Sstevel@tonic-gate #endif
870Sstevel@tonic-gate 
880Sstevel@tonic-gate #endif	/* _SYS_RWLOCK_H */
89