xref: /titanic_52/usr/src/uts/common/sys/rwlock.h (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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 (c) 1991-1998 by Sun Microsystems, Inc.
24*7c478bd9Sstevel@tonic-gate  * All rights reserved.
25*7c478bd9Sstevel@tonic-gate  */
26*7c478bd9Sstevel@tonic-gate 
27*7c478bd9Sstevel@tonic-gate #ifndef _SYS_RWLOCK_H
28*7c478bd9Sstevel@tonic-gate #define	_SYS_RWLOCK_H
29*7c478bd9Sstevel@tonic-gate 
30*7c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
31*7c478bd9Sstevel@tonic-gate 
32*7c478bd9Sstevel@tonic-gate /*
33*7c478bd9Sstevel@tonic-gate  * Public interface to readers/writer locks.  See rwlock(9F) for details.
34*7c478bd9Sstevel@tonic-gate  */
35*7c478bd9Sstevel@tonic-gate 
36*7c478bd9Sstevel@tonic-gate #include <sys/types.h>
37*7c478bd9Sstevel@tonic-gate 
38*7c478bd9Sstevel@tonic-gate #ifdef	__cplusplus
39*7c478bd9Sstevel@tonic-gate extern "C" {
40*7c478bd9Sstevel@tonic-gate #endif
41*7c478bd9Sstevel@tonic-gate 
42*7c478bd9Sstevel@tonic-gate #ifndef _ASM
43*7c478bd9Sstevel@tonic-gate 
44*7c478bd9Sstevel@tonic-gate typedef enum {
45*7c478bd9Sstevel@tonic-gate 	RW_DRIVER = 2,		/* driver (DDI) rwlock */
46*7c478bd9Sstevel@tonic-gate 	RW_DEFAULT = 4		/* kernel default rwlock */
47*7c478bd9Sstevel@tonic-gate } krw_type_t;
48*7c478bd9Sstevel@tonic-gate 
49*7c478bd9Sstevel@tonic-gate typedef enum {
50*7c478bd9Sstevel@tonic-gate 	RW_WRITER,
51*7c478bd9Sstevel@tonic-gate 	RW_READER
52*7c478bd9Sstevel@tonic-gate } krw_t;
53*7c478bd9Sstevel@tonic-gate 
54*7c478bd9Sstevel@tonic-gate typedef struct _krwlock {
55*7c478bd9Sstevel@tonic-gate 	void	*_opaque[1];
56*7c478bd9Sstevel@tonic-gate } krwlock_t;
57*7c478bd9Sstevel@tonic-gate 
58*7c478bd9Sstevel@tonic-gate #if defined(_KERNEL)
59*7c478bd9Sstevel@tonic-gate 
60*7c478bd9Sstevel@tonic-gate #define	RW_READ_HELD(x)		(rw_read_held((x)))
61*7c478bd9Sstevel@tonic-gate #define	RW_WRITE_HELD(x)	(rw_write_held((x)))
62*7c478bd9Sstevel@tonic-gate #define	RW_LOCK_HELD(x)		(rw_lock_held((x)))
63*7c478bd9Sstevel@tonic-gate #define	RW_ISWRITER(x)		(rw_iswriter(x))
64*7c478bd9Sstevel@tonic-gate 
65*7c478bd9Sstevel@tonic-gate extern	void	rw_init(krwlock_t *, char *, krw_type_t, void *);
66*7c478bd9Sstevel@tonic-gate extern	void	rw_destroy(krwlock_t *);
67*7c478bd9Sstevel@tonic-gate extern	void	rw_enter(krwlock_t *, krw_t);
68*7c478bd9Sstevel@tonic-gate extern	int	rw_tryenter(krwlock_t *, krw_t);
69*7c478bd9Sstevel@tonic-gate extern	void	rw_exit(krwlock_t *);
70*7c478bd9Sstevel@tonic-gate extern	void	rw_downgrade(krwlock_t *);
71*7c478bd9Sstevel@tonic-gate extern	int	rw_tryupgrade(krwlock_t *);
72*7c478bd9Sstevel@tonic-gate extern	int	rw_read_held(krwlock_t *);
73*7c478bd9Sstevel@tonic-gate extern	int	rw_write_held(krwlock_t *);
74*7c478bd9Sstevel@tonic-gate extern	int	rw_lock_held(krwlock_t *);
75*7c478bd9Sstevel@tonic-gate extern	int	rw_read_locked(krwlock_t *);
76*7c478bd9Sstevel@tonic-gate extern	int	rw_iswriter(krwlock_t *);
77*7c478bd9Sstevel@tonic-gate extern	struct _kthread *rw_owner(krwlock_t *);
78*7c478bd9Sstevel@tonic-gate 
79*7c478bd9Sstevel@tonic-gate #endif	/* defined(_KERNEL) */
80*7c478bd9Sstevel@tonic-gate 
81*7c478bd9Sstevel@tonic-gate #endif	/* _ASM */
82*7c478bd9Sstevel@tonic-gate 
83*7c478bd9Sstevel@tonic-gate #ifdef	__cplusplus
84*7c478bd9Sstevel@tonic-gate }
85*7c478bd9Sstevel@tonic-gate #endif
86*7c478bd9Sstevel@tonic-gate 
87*7c478bd9Sstevel@tonic-gate #endif	/* _SYS_RWLOCK_H */
88