xref: /freebsd/sys/sys/rmlock.h (revision 72143e89bb430c3b1406b399b810806904f6c882)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2007 Stephan Uphoff <ups@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the author nor the names of any co-contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $FreeBSD$
32  */
33 
34 #ifndef _SYS_RMLOCK_H_
35 #define _SYS_RMLOCK_H_
36 
37 #include <sys/mutex.h>
38 #include <sys/sx.h>
39 #include <sys/_lock.h>
40 #include <sys/_rmlock.h>
41 
42 #ifdef _KERNEL
43 
44 /*
45  * Flags passed to rm_init_flags(9).
46  */
47 #define	RM_NOWITNESS	0x00000001
48 #define	RM_RECURSE	0x00000002
49 #define	RM_SLEEPABLE	0x00000004
50 #define	RM_NEW		0x00000008
51 
52 void	rm_init(struct rmlock *rm, const char *name);
53 void	rm_init_flags(struct rmlock *rm, const char *name, int opts);
54 void	rm_destroy(struct rmlock *rm);
55 int	rm_wowned(const struct rmlock *rm);
56 void	rm_sysinit(void *arg);
57 
58 void	_rm_wlock_debug(struct rmlock *rm, const char *file, int line);
59 void	_rm_wunlock_debug(struct rmlock *rm, const char *file, int line);
60 int	_rm_rlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
61 	    int trylock, const char *file, int line);
62 void	_rm_runlock_debug(struct rmlock *rm,  struct rm_priotracker *tracker,
63 	    const char *file, int line);
64 
65 void	_rm_wlock(struct rmlock *rm);
66 void	_rm_wunlock(struct rmlock *rm);
67 int	_rm_rlock(struct rmlock *rm, struct rm_priotracker *tracker,
68 	    int trylock);
69 void	_rm_runlock(struct rmlock *rm,  struct rm_priotracker *tracker);
70 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
71 void	_rm_assert(const struct rmlock *rm, int what, const char *file,
72 	    int line);
73 #endif
74 
75 /*
76  * Public interface for lock operations.
77  */
78 #ifndef LOCK_DEBUG
79 #error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/rmlock.h>
80 #endif
81 
82 #if LOCK_DEBUG > 0
83 #define	rm_wlock(rm)	_rm_wlock_debug((rm), LOCK_FILE, LOCK_LINE)
84 #define	rm_wunlock(rm)	_rm_wunlock_debug((rm), LOCK_FILE, LOCK_LINE)
85 #define	rm_rlock(rm,tracker)  \
86     ((void)_rm_rlock_debug((rm),(tracker), 0, LOCK_FILE, LOCK_LINE ))
87 #define	rm_try_rlock(rm,tracker)  \
88     _rm_rlock_debug((rm),(tracker), 1, LOCK_FILE, LOCK_LINE )
89 #define	rm_runlock(rm,tracker)	\
90     _rm_runlock_debug((rm), (tracker), LOCK_FILE, LOCK_LINE )
91 #else
92 #define	rm_wlock(rm)			_rm_wlock((rm))
93 #define	rm_wunlock(rm)			_rm_wunlock((rm))
94 #define	rm_rlock(rm,tracker)		((void)_rm_rlock((rm),(tracker), 0))
95 #define	rm_try_rlock(rm,tracker)	_rm_rlock((rm),(tracker), 1)
96 #define	rm_runlock(rm,tracker)		_rm_runlock((rm), (tracker))
97 #endif
98 #define	rm_sleep(chan, rm, pri, wmesg, timo)				\
99 	_sleep((chan), &(rm)->lock_object, (pri), (wmesg),		\
100 	    tick_sbt * (timo), 0, C_HARDCLOCK)
101 
102 struct rm_args {
103 	struct rmlock	*ra_rm;
104 	const char 	*ra_desc;
105 	int		ra_flags;
106 };
107 
108 #define	RM_SYSINIT_FLAGS(name, rm, desc, flags)				\
109 	static struct rm_args name##_args = {				\
110 		(rm),							\
111 		(desc),							\
112 		(flags),						\
113 	};								\
114 	SYSINIT(name##_rm_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
115 	    rm_sysinit, &name##_args);					\
116 	SYSUNINIT(name##_rm_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
117 	    rm_destroy, (rm))
118 
119 #define	RM_SYSINIT(name, rm, desc)	RM_SYSINIT_FLAGS(name, rm, desc, 0)
120 
121 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
122 #define	RA_LOCKED		LA_LOCKED
123 #define	RA_RLOCKED		LA_SLOCKED
124 #define	RA_WLOCKED		LA_XLOCKED
125 #define	RA_UNLOCKED		LA_UNLOCKED
126 #define	RA_RECURSED		LA_RECURSED
127 #define	RA_NOTRECURSED		LA_NOTRECURSED
128 #endif
129 
130 #ifdef INVARIANTS
131 #define	rm_assert(rm, what)	_rm_assert((rm), (what), LOCK_FILE, LOCK_LINE)
132 #else
133 #define	rm_assert(rm, what)
134 #endif
135 
136 void	rms_init(struct rmslock *rms, const char *name);
137 void	rms_destroy(struct rmslock *rms);
138 void	rms_rlock(struct rmslock *rms);
139 int	rms_try_rlock(struct rmslock *rms);
140 void	rms_runlock(struct rmslock *rms);
141 void	rms_wlock(struct rmslock *rms);
142 void	rms_wunlock(struct rmslock *rms);
143 void	rms_unlock(struct rmslock *rms);
144 
145 static inline int
146 rms_wowned(struct rmslock *rms)
147 {
148 
149 	return (rms->owner == curthread);
150 }
151 
152 /*
153  * Only valid to call if you hold the lock in some manner.
154  */
155 static inline int
156 rms_rowned(struct rmslock *rms)
157 {
158 
159 	return (rms->readers > 0);
160 }
161 
162 static inline int
163 rms_owned_any(struct rmslock *rms)
164 {
165 
166 	if (rms_wowned(rms))
167 		return (1);
168 
169 	return (rms_rowned(rms));
170 }
171 
172 #endif /* _KERNEL */
173 #endif /* !_SYS_RMLOCK_H_ */
174