xref: /freebsd/sys/sys/lockmgr.h (revision f05cddf9)
1 /*-
2  * Copyright (c) 2008 Attilio Rao <attilio@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice(s), this list of conditions and the following disclaimer as
10  *    the first lines of this file unmodified other than the possible
11  *    addition of one or more copyright notices.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice(s), this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
26  * DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #ifndef	_SYS_LOCKMGR_H_
32 #define	_SYS_LOCKMGR_H_
33 
34 #include <sys/_lock.h>
35 #include <sys/_lockmgr.h>
36 #include <sys/_mutex.h>
37 #include <sys/_rwlock.h>
38 
39 #define	LK_SHARE			0x01
40 #define	LK_SHARED_WAITERS		0x02
41 #define	LK_EXCLUSIVE_WAITERS		0x04
42 #define	LK_EXCLUSIVE_SPINNERS		0x08
43 #define	LK_ALL_WAITERS							\
44 	(LK_SHARED_WAITERS | LK_EXCLUSIVE_WAITERS)
45 #define	LK_FLAGMASK							\
46 	(LK_SHARE | LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS)
47 
48 #define	LK_HOLDER(x)			((x) & ~LK_FLAGMASK)
49 #define	LK_SHARERS_SHIFT		4
50 #define	LK_SHARERS(x)			(LK_HOLDER(x) >> LK_SHARERS_SHIFT)
51 #define	LK_SHARERS_LOCK(x)		((x) << LK_SHARERS_SHIFT | LK_SHARE)
52 #define	LK_ONE_SHARER			(1 << LK_SHARERS_SHIFT)
53 #define	LK_UNLOCKED			LK_SHARERS_LOCK(0)
54 #define	LK_KERNPROC			((uintptr_t)(-1) & ~LK_FLAGMASK)
55 
56 #ifdef _KERNEL
57 
58 #if !defined(LOCK_FILE) || !defined(LOCK_LINE)
59 #error	"LOCK_FILE and LOCK_LINE not defined, include <sys/lock.h> before"
60 #endif
61 
62 struct thread;
63 #define	lk_recurse	lock_object.lo_data
64 
65 /*
66  * Function prototipes.  Routines that start with an underscore are not part
67  * of the public interface and might be wrappered with a macro.
68  */
69 int	 __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
70 	    const char *wmesg, int prio, int timo, const char *file, int line);
71 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
72 void	 _lockmgr_assert(const struct lock *lk, int what, const char *file, int line);
73 #endif
74 void	 _lockmgr_disown(struct lock *lk, const char *file, int line);
75 
76 void	 lockallowrecurse(struct lock *lk);
77 void	 lockallowshare(struct lock *lk);
78 void	 lockdestroy(struct lock *lk);
79 void	 lockdisablerecurse(struct lock *lk);
80 void	 lockinit(struct lock *lk, int prio, const char *wmesg, int timo,
81 	    int flags);
82 #ifdef DDB
83 int	 lockmgr_chain(struct thread *td, struct thread **ownerp);
84 #endif
85 void	 lockmgr_printinfo(const struct lock *lk);
86 int	 lockstatus(const struct lock *lk);
87 
88 /*
89  * As far as the ilk can be a static NULL pointer these functions need a
90  * strict prototype in order to safely use the lock_object member.
91  */
92 static __inline int
93 _lockmgr_args(struct lock *lk, u_int flags, struct mtx *ilk, const char *wmesg,
94     int prio, int timo, const char *file, int line)
95 {
96 
97 	return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
98 	    NULL, wmesg, prio, timo, file, line));
99 }
100 
101 static __inline int
102 _lockmgr_args_rw(struct lock *lk, u_int flags, struct rwlock *ilk,
103     const char *wmesg, int prio, int timo, const char *file, int line)
104 {
105 
106 	return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
107 	    NULL, wmesg, prio, timo, file, line));
108 }
109 
110 /*
111  * Define aliases in order to complete lockmgr KPI.
112  */
113 #define	lockmgr(lk, flags, ilk)						\
114 	_lockmgr_args((lk), (flags), (ilk), LK_WMESG_DEFAULT,		\
115 	    LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
116 #define	lockmgr_args(lk, flags, ilk, wmesg, prio, timo)			\
117 	_lockmgr_args((lk), (flags), (ilk), (wmesg), (prio), (timo),	\
118 	    LOCK_FILE, LOCK_LINE)
119 #define	lockmgr_args_rw(lk, flags, ilk, wmesg, prio, timo)		\
120 	_lockmgr_args_rw((lk), (flags), (ilk), (wmesg), (prio), (timo),	\
121 	    LOCK_FILE, LOCK_LINE)
122 #define	lockmgr_disown(lk)						\
123 	_lockmgr_disown((lk), LOCK_FILE, LOCK_LINE)
124 #define	lockmgr_recursed(lk)						\
125 	((lk)->lk_recurse != 0)
126 #define	lockmgr_rw(lk, flags, ilk)					\
127 	_lockmgr_args_rw((lk), (flags), (ilk), LK_WMESG_DEFAULT,	\
128 	    LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
129 #define	lockmgr_waiters(lk)						\
130 	((lk)->lk_lock & LK_ALL_WAITERS)
131 #ifdef INVARIANTS
132 #define	lockmgr_assert(lk, what)					\
133 	_lockmgr_assert((lk), (what), LOCK_FILE, LOCK_LINE)
134 #else
135 #define	lockmgr_assert(lk, what)
136 #endif
137 
138 /*
139  * Flags for lockinit().
140  */
141 #define	LK_INIT_MASK	0x0000FF
142 #define	LK_CANRECURSE	0x000001
143 #define	LK_NODUP	0x000002
144 #define	LK_NOPROFILE	0x000004
145 #define	LK_NOSHARE	0x000008
146 #define	LK_NOWITNESS	0x000010
147 #define	LK_QUIET	0x000020
148 #define	LK_ADAPTIVE	0x000040
149 #define	LK_IS_VNODE	0x000080	/* Tell WITNESS about a VNODE lock */
150 
151 /*
152  * Additional attributes to be used in lockmgr().
153  */
154 #define	LK_EATTR_MASK	0x00FF00
155 #define	LK_INTERLOCK	0x000100
156 #define	LK_NOWAIT	0x000200
157 #define	LK_RETRY	0x000400
158 #define	LK_SLEEPFAIL	0x000800
159 #define	LK_TIMELOCK	0x001000
160 
161 /*
162  * Operations for lockmgr().
163  */
164 #define	LK_TYPE_MASK	0xFF0000
165 #define	LK_DOWNGRADE	0x010000
166 #define	LK_DRAIN	0x020000
167 #define	LK_EXCLOTHER	0x040000
168 #define	LK_EXCLUSIVE	0x080000
169 #define	LK_RELEASE	0x100000
170 #define	LK_SHARED	0x200000
171 #define	LK_UPGRADE	0x400000
172 
173 #define	LK_TOTAL_MASK	(LK_INIT_MASK | LK_EATTR_MASK | LK_TYPE_MASK)
174 
175 /*
176  * Default values for lockmgr_args().
177  */
178 #define	LK_WMESG_DEFAULT	(NULL)
179 #define	LK_PRIO_DEFAULT		(0)
180 #define	LK_TIMO_DEFAULT		(0)
181 
182 /*
183  * Assertion flags.
184  */
185 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
186 #define	KA_LOCKED	LA_LOCKED
187 #define	KA_SLOCKED	LA_SLOCKED
188 #define	KA_XLOCKED	LA_XLOCKED
189 #define	KA_UNLOCKED	LA_UNLOCKED
190 #define	KA_RECURSED	LA_RECURSED
191 #define	KA_NOTRECURSED	LA_NOTRECURSED
192 #endif
193 
194 #endif /* _KERNEL */
195 
196 #endif /* !_SYS_LOCKMGR_H_ */
197