xref: /freebsd/sys/sys/lockmgr.h (revision b00ab754)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008 Attilio Rao <attilio@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(s), this list of conditions and the following disclaimer as
12  *    the first lines of this file unmodified other than the possible
13  *    addition of one or more copyright notices.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice(s), this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
25  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
28  * DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #ifndef	_SYS_LOCKMGR_H_
34 #define	_SYS_LOCKMGR_H_
35 
36 #include <sys/_lock.h>
37 #include <sys/_lockmgr.h>
38 #include <sys/_mutex.h>
39 #include <sys/_rwlock.h>
40 
41 #define	LK_SHARE			0x01
42 #define	LK_SHARED_WAITERS		0x02
43 #define	LK_EXCLUSIVE_WAITERS		0x04
44 #define	LK_EXCLUSIVE_SPINNERS		0x08
45 #define	LK_ALL_WAITERS							\
46 	(LK_SHARED_WAITERS | LK_EXCLUSIVE_WAITERS)
47 #define	LK_FLAGMASK							\
48 	(LK_SHARE | LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS)
49 
50 #define	LK_HOLDER(x)			((x) & ~LK_FLAGMASK)
51 #define	LK_SHARERS_SHIFT		4
52 #define	LK_SHARERS(x)			(LK_HOLDER(x) >> LK_SHARERS_SHIFT)
53 #define	LK_SHARERS_LOCK(x)		((x) << LK_SHARERS_SHIFT | LK_SHARE)
54 #define	LK_ONE_SHARER			(1 << LK_SHARERS_SHIFT)
55 #define	LK_UNLOCKED			LK_SHARERS_LOCK(0)
56 #define	LK_KERNPROC			((uintptr_t)(-1) & ~LK_FLAGMASK)
57 
58 #ifdef _KERNEL
59 
60 #if !defined(LOCK_FILE) || !defined(LOCK_LINE)
61 #error	"LOCK_FILE and LOCK_LINE not defined, include <sys/lock.h> before"
62 #endif
63 
64 struct thread;
65 #define	lk_recurse	lock_object.lo_data
66 
67 /*
68  * Function prototipes.  Routines that start with an underscore are not part
69  * of the public interface and might be wrappered with a macro.
70  */
71 int	 __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
72 	    const char *wmesg, int prio, int timo, const char *file, int line);
73 int	 lockmgr_lock_fast_path(struct lock *lk, u_int flags,
74 	    struct lock_object *ilk, const char *file, int line);
75 int	 lockmgr_unlock_fast_path(struct lock *lk, u_int flags,
76 	    struct lock_object *ilk);
77 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
78 void	 _lockmgr_assert(const struct lock *lk, int what, const char *file, int line);
79 #endif
80 void	 _lockmgr_disown(struct lock *lk, const char *file, int line);
81 
82 void	 lockallowrecurse(struct lock *lk);
83 void	 lockallowshare(struct lock *lk);
84 void	 lockdestroy(struct lock *lk);
85 void	 lockdisablerecurse(struct lock *lk);
86 void	 lockdisableshare(struct lock *lk);
87 void	 lockinit(struct lock *lk, int prio, const char *wmesg, int timo,
88 	    int flags);
89 #ifdef DDB
90 int	 lockmgr_chain(struct thread *td, struct thread **ownerp);
91 #endif
92 void	 lockmgr_printinfo(const struct lock *lk);
93 int	 lockstatus(const struct lock *lk);
94 
95 /*
96  * As far as the ilk can be a static NULL pointer these functions need a
97  * strict prototype in order to safely use the lock_object member.
98  */
99 static __inline int
100 _lockmgr_args(struct lock *lk, u_int flags, struct mtx *ilk, const char *wmesg,
101     int prio, int timo, const char *file, int line)
102 {
103 
104 	return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
105 	    NULL, wmesg, prio, timo, file, line));
106 }
107 
108 static __inline int
109 _lockmgr_args_rw(struct lock *lk, u_int flags, struct rwlock *ilk,
110     const char *wmesg, int prio, int timo, const char *file, int line)
111 {
112 
113 	return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
114 	    NULL, wmesg, prio, timo, file, line));
115 }
116 
117 /*
118  * Define aliases in order to complete lockmgr KPI.
119  */
120 #define	lockmgr(lk, flags, ilk)						\
121 	_lockmgr_args((lk), (flags), (ilk), LK_WMESG_DEFAULT,		\
122 	    LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
123 #define	lockmgr_args(lk, flags, ilk, wmesg, prio, timo)			\
124 	_lockmgr_args((lk), (flags), (ilk), (wmesg), (prio), (timo),	\
125 	    LOCK_FILE, LOCK_LINE)
126 #define	lockmgr_args_rw(lk, flags, ilk, wmesg, prio, timo)		\
127 	_lockmgr_args_rw((lk), (flags), (ilk), (wmesg), (prio), (timo),	\
128 	    LOCK_FILE, LOCK_LINE)
129 #define	lockmgr_disown(lk)						\
130 	_lockmgr_disown((lk), LOCK_FILE, LOCK_LINE)
131 #define	lockmgr_recursed(lk)						\
132 	((lk)->lk_recurse != 0)
133 #define	lockmgr_rw(lk, flags, ilk)					\
134 	_lockmgr_args_rw((lk), (flags), (ilk), LK_WMESG_DEFAULT,	\
135 	    LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
136 #ifdef INVARIANTS
137 #define	lockmgr_assert(lk, what)					\
138 	_lockmgr_assert((lk), (what), LOCK_FILE, LOCK_LINE)
139 #else
140 #define	lockmgr_assert(lk, what)
141 #endif
142 
143 /*
144  * Flags for lockinit().
145  */
146 #define	LK_INIT_MASK	0x0000FF
147 #define	LK_CANRECURSE	0x000001
148 #define	LK_NODUP	0x000002
149 #define	LK_NOPROFILE	0x000004
150 #define	LK_NOSHARE	0x000008
151 #define	LK_NOWITNESS	0x000010
152 #define	LK_QUIET	0x000020
153 #define	LK_ADAPTIVE	0x000040
154 #define	LK_IS_VNODE	0x000080	/* Tell WITNESS about a VNODE lock */
155 
156 /*
157  * Additional attributes to be used in lockmgr().
158  */
159 #define	LK_EATTR_MASK	0x00FF00
160 #define	LK_INTERLOCK	0x000100
161 #define	LK_NOWAIT	0x000200
162 #define	LK_RETRY	0x000400
163 #define	LK_SLEEPFAIL	0x000800
164 #define	LK_TIMELOCK	0x001000
165 #define	LK_NODDLKTREAT	0x002000
166 #define	LK_VNHELD	0x004000
167 
168 /*
169  * Operations for lockmgr().
170  */
171 #define	LK_TYPE_MASK	0xFF0000
172 #define	LK_DOWNGRADE	0x010000
173 #define	LK_DRAIN	0x020000
174 #define	LK_EXCLOTHER	0x040000
175 #define	LK_EXCLUSIVE	0x080000
176 #define	LK_RELEASE	0x100000
177 #define	LK_SHARED	0x200000
178 #define	LK_UPGRADE	0x400000
179 #define	LK_TRYUPGRADE	0x800000
180 
181 #define	LK_TOTAL_MASK	(LK_INIT_MASK | LK_EATTR_MASK | LK_TYPE_MASK)
182 
183 /*
184  * Default values for lockmgr_args().
185  */
186 #define	LK_WMESG_DEFAULT	(NULL)
187 #define	LK_PRIO_DEFAULT		(0)
188 #define	LK_TIMO_DEFAULT		(0)
189 
190 /*
191  * Assertion flags.
192  */
193 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
194 #define	KA_LOCKED	LA_LOCKED
195 #define	KA_SLOCKED	LA_SLOCKED
196 #define	KA_XLOCKED	LA_XLOCKED
197 #define	KA_UNLOCKED	LA_UNLOCKED
198 #define	KA_RECURSED	LA_RECURSED
199 #define	KA_NOTRECURSED	LA_NOTRECURSED
200 #endif
201 
202 #endif /* _KERNEL */
203 
204 #endif /* !_SYS_LOCKMGR_H_ */
205