xref: /freebsd/sys/sys/rmlock.h (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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 
32 #ifndef _SYS_RMLOCK_H_
33 #define _SYS_RMLOCK_H_
34 
35 #include <sys/mutex.h>
36 #include <sys/sx.h>
37 #include <sys/_lock.h>
38 #include <sys/_rmlock.h>
39 
40 #ifdef _KERNEL
41 
42 /*
43  * Flags passed to rm_init_flags(9).
44  */
45 #define	RM_NOWITNESS	0x00000001
46 #define	RM_RECURSE	0x00000002
47 #define	RM_SLEEPABLE	0x00000004
48 #define	RM_NEW		0x00000008
49 #define	RM_DUPOK	0x00000010
50 
51 void	rm_init(struct rmlock *rm, const char *name);
52 void	rm_init_flags(struct rmlock *rm, const char *name, int opts);
53 void	rm_destroy(struct rmlock *rm);
54 int	rm_wowned(const struct rmlock *rm);
55 void	rm_sysinit(void *arg);
56 
57 void	_rm_wlock_debug(struct rmlock *rm, const char *file, int line);
58 void	_rm_wunlock_debug(struct rmlock *rm, const char *file, int line);
59 int	_rm_rlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
60 	    int trylock, const char *file, int line);
61 void	_rm_runlock_debug(struct rmlock *rm,  struct rm_priotracker *tracker,
62 	    const char *file, int line);
63 
64 void	_rm_wlock(struct rmlock *rm);
65 void	_rm_wunlock(struct rmlock *rm);
66 int	_rm_rlock(struct rmlock *rm, struct rm_priotracker *tracker,
67 	    int trylock);
68 void	_rm_runlock(struct rmlock *rm,  struct rm_priotracker *tracker);
69 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
70 void	_rm_assert(const struct rmlock *rm, int what, const char *file,
71 	    int line);
72 #endif
73 
74 /*
75  * Public interface for lock operations.
76  */
77 #ifndef LOCK_DEBUG
78 #error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/rmlock.h>
79 #endif
80 
81 #if LOCK_DEBUG > 0
82 #define	rm_wlock(rm)	_rm_wlock_debug((rm), LOCK_FILE, LOCK_LINE)
83 #define	rm_wunlock(rm)	_rm_wunlock_debug((rm), LOCK_FILE, LOCK_LINE)
84 #define	rm_rlock(rm,tracker)  \
85     ((void)_rm_rlock_debug((rm),(tracker), 0, LOCK_FILE, LOCK_LINE ))
86 #define	rm_try_rlock(rm,tracker)  \
87     _rm_rlock_debug((rm),(tracker), 1, LOCK_FILE, LOCK_LINE )
88 #define	rm_runlock(rm,tracker)	\
89     _rm_runlock_debug((rm), (tracker), LOCK_FILE, LOCK_LINE )
90 #else
91 #define	rm_wlock(rm)			_rm_wlock((rm))
92 #define	rm_wunlock(rm)			_rm_wunlock((rm))
93 #define	rm_rlock(rm,tracker)		((void)_rm_rlock((rm),(tracker), 0))
94 #define	rm_try_rlock(rm,tracker)	_rm_rlock((rm),(tracker), 1)
95 #define	rm_runlock(rm,tracker)		_rm_runlock((rm), (tracker))
96 #endif
97 #define	rm_sleep(chan, rm, pri, wmesg, timo)				\
98 	_sleep((chan), &(rm)->lock_object, (pri), (wmesg),		\
99 	    tick_sbt * (timo), 0, C_HARDCLOCK)
100 
101 struct rm_args {
102 	struct rmlock	*ra_rm;
103 	const char 	*ra_desc;
104 	int		ra_flags;
105 };
106 
107 #define	RM_SYSINIT_FLAGS(name, rm, desc, flags)				\
108 	static struct rm_args name##_args = {				\
109 		(rm),							\
110 		(desc),							\
111 		(flags),						\
112 	};								\
113 	SYSINIT(name##_rm_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
114 	    rm_sysinit, &name##_args);					\
115 	SYSUNINIT(name##_rm_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
116 	    rm_destroy, (rm))
117 
118 #define	RM_SYSINIT(name, rm, desc)	RM_SYSINIT_FLAGS(name, rm, desc, 0)
119 
120 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
121 #define	RA_LOCKED		LA_LOCKED
122 #define	RA_RLOCKED		LA_SLOCKED
123 #define	RA_WLOCKED		LA_XLOCKED
124 #define	RA_UNLOCKED		LA_UNLOCKED
125 #define	RA_RECURSED		LA_RECURSED
126 #define	RA_NOTRECURSED		LA_NOTRECURSED
127 #endif
128 
129 #ifdef INVARIANTS
130 #define	rm_assert(rm, what)	_rm_assert((rm), (what), LOCK_FILE, LOCK_LINE)
131 #else
132 #define	rm_assert(rm, what)
133 #endif
134 
135 void	rms_init(struct rmslock *rms, const char *name);
136 void	rms_destroy(struct rmslock *rms);
137 void	rms_rlock(struct rmslock *rms);
138 int	rms_try_rlock(struct rmslock *rms);
139 void	rms_runlock(struct rmslock *rms);
140 void	rms_wlock(struct rmslock *rms);
141 void	rms_wunlock(struct rmslock *rms);
142 void	rms_unlock(struct rmslock *rms);
143 
144 static inline int
145 rms_wowned(struct rmslock *rms)
146 {
147 
148 	return (rms->owner == curthread);
149 }
150 
151 #ifdef INVARIANTS
152 #define rms_assert_rlock_ok(x)	\
153 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
154 #else
155 #define rms_assert_rlock_ok(x)
156 #endif
157 
158 #ifdef INVARIANTS
159 /*
160  * For assertion purposes.
161  *
162  * Main limitation is that we at best can tell there are readers, but not
163  * whether curthread is one of them.
164  */
165 static inline int
166 rms_rowned(struct rmslock *rms)
167 {
168 
169 	return (rms->debug_readers > 0);
170 }
171 
172 static inline int
173 rms_owned_any(struct rmslock *rms)
174 {
175 
176 	if (rms_wowned(rms))
177 		return (1);
178 
179 	return (rms_rowned(rms));
180 }
181 #endif
182 
183 #endif /* _KERNEL */
184 #endif /* !_SYS_RMLOCK_H_ */
185