2 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
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16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
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18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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28 * from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
35 #include <sys/queue.h>
36 #include <sys/_lock.h>
41 * Lock classes. Each lock has a class which describes characteristics
42 * common to all types of locks of a given class.
44 * Spin locks in general must always protect against preemption, as it is
45 * an error to perform any type of context switch while holding a spin lock.
46 * Also, for an individual lock to be recursable, its class must allow
47 * recursion and the lock itself must explicitly allow recursion.
53 void (*lc_ddb_show)(struct lock_object *lock);
56 #define LC_SLEEPLOCK 0x00000001 /* Sleep lock. */
57 #define LC_SPINLOCK 0x00000002 /* Spin lock. */
58 #define LC_SLEEPABLE 0x00000004 /* Sleeping allowed with this lock. */
59 #define LC_RECURSABLE 0x00000008 /* Locks of this type may recurse. */
60 #define LC_UPGRADABLE 0x00000010 /* Upgrades and downgrades permitted. */
62 #define LO_CLASSFLAGS 0x0000ffff /* Class specific flags. */
63 #define LO_INITIALIZED 0x00010000 /* Lock has been initialized. */
64 #define LO_WITNESS 0x00020000 /* Should witness monitor this lock. */
65 #define LO_QUIET 0x00040000 /* Don't log locking operations. */
66 #define LO_RECURSABLE 0x00080000 /* Lock may recurse. */
67 #define LO_SLEEPABLE 0x00100000 /* Lock may be held while sleeping. */
68 #define LO_UPGRADABLE 0x00200000 /* Lock may be upgraded/downgraded. */
69 #define LO_DUPOK 0x00400000 /* Don't check for duplicate acquires */
71 #define LOCK_CLASS(lock) ((lock)->lo_class)
73 #define LI_RECURSEMASK 0x0000ffff /* Recursion depth of lock instance. */
74 #define LI_EXCLUSIVE 0x00010000 /* Exclusive lock instance. */
77 * Option flags passed to lock operations that witness also needs to know
78 * about or that are generic across all locks.
80 #define LOP_NEWORDER 0x00000001 /* Define a new lock order. */
81 #define LOP_QUIET 0x00000002 /* Don't log locking operations. */
82 #define LOP_TRYLOCK 0x00000004 /* Don't check lock order. */
83 #define LOP_EXCLUSIVE 0x00000008 /* Exclusive lock. */
84 #define LOP_DUPOK 0x00000010 /* Don't check for duplicate acquires */
86 /* Flags passed to witness_assert. */
87 #define LA_UNLOCKED 0x00000000 /* Lock is unlocked. */
88 #define LA_LOCKED 0x00000001 /* Lock is at least share locked. */
89 #define LA_SLOCKED 0x00000002 /* Lock is exactly share locked. */
90 #define LA_XLOCKED 0x00000004 /* Lock is exclusively locked. */
91 #define LA_RECURSED 0x00000008 /* Lock is recursed. */
92 #define LA_NOTRECURSED 0x00000010 /* Lock is not recursed. */
96 * Lock instances. A lock instance is the data associated with a lock while
97 * it is held by witness. For example, a lock instance will hold the
98 * recursion count of a lock. Lock instances are held in lists. Spin locks
99 * are held in a per-cpu list while sleep locks are held in per-process list.
101 struct lock_instance {
102 struct lock_object *li_lock;
103 const char *li_file; /* File and line of last acquire. */
105 u_int li_flags; /* Recursion count and LI_* flags. */
109 * A simple list type used to build the list of locks held by a process
110 * or CPU. We can't simply embed the list in struct lock_object since a
111 * lock may be held by more than one process if it is a shared lock. Locks
112 * are added to the head of the list, so we fill up each list entry from
113 * "the back" logically. To ease some of the arithmetic, we actually fill
114 * in each list entry the normal way (childer[0] then children[1], etc.) but
115 * when we traverse the list we read children[count-1] as the first entry
116 * down to children[0] as the final entry.
118 #define LOCK_NCHILDREN 3
120 struct lock_list_entry {
121 struct lock_list_entry *ll_next;
122 struct lock_instance ll_children[LOCK_NCHILDREN];
127 * If any of WITNESS, INVARIANTS, or KTR_LOCK KTR tracing has been enabled,
128 * then turn on LOCK_DEBUG. When this option is on, extra debugging
129 * facilities such as tracking the file and line number of lock operations
130 * are enabled. Also, mutex locking operations are not inlined to avoid
131 * bloat from all the extra debugging code. We also have to turn on all the
132 * calling conventions for this debugging code in modules so that modules can
133 * work with both debug and non-debug kernels.
135 #if defined(KLD_MODULE) || defined(WITNESS) || defined(INVARIANTS) || defined(INVARIANT_SUPPORT) || defined(KTR) || defined(MUTEX_PROFILING)
142 * In the LOCK_DEBUG case, use the filename and line numbers for debugging
143 * operations. Otherwise, use default values to avoid the unneeded bloat.
146 #define LOCK_FILE __FILE__
147 #define LOCK_LINE __LINE__
149 #define LOCK_FILE NULL
154 * Macros for KTR_LOCK tracing.
156 * opname - name of this operation (LOCK/UNLOCK/SLOCK, etc.)
157 * lo - struct lock_object * for this lock
158 * flags - flags passed to the lock operation
159 * recurse - this locks recursion level (or 0 if class is not recursable)
160 * result - result of a try lock operation
164 #define LOCK_LOG_TEST(lo, flags) \
165 (((flags) & LOP_QUIET) == 0 && ((lo)->lo_flags & LO_QUIET) == 0)
167 #define LOCK_LOG_LOCK(opname, lo, flags, recurse, file, line) do { \
168 if (LOCK_LOG_TEST((lo), (flags))) \
169 CTR5(KTR_LOCK, opname " (%s) %s r = %d at %s:%d", \
170 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \
171 (u_int)(recurse), (file), (line)); \
174 #define LOCK_LOG_TRY(opname, lo, flags, result, file, line) do { \
175 if (LOCK_LOG_TEST((lo), (flags))) \
176 CTR5(KTR_LOCK, "TRY_" opname " (%s) %s result=%d at %s:%d",\
177 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \
178 (u_int)(result), (file), (line)); \
181 #define LOCK_LOG_INIT(lo, flags) do { \
182 if (LOCK_LOG_TEST((lo), (flags))) \
183 CTR4(KTR_LOCK, "%s: %p (%s) %s", __func__, (lo), \
184 LOCK_CLASS(lo)->lc_name, (lo)->lo_name); \
187 #define LOCK_LOG_DESTROY(lo, flags) LOCK_LOG_INIT(lo, flags)
189 #define lock_initalized(lo) ((lo)->lo_flags & LO_INITIALIZED)
192 * Helpful macros for quickly coming up with assertions with informative
195 #define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__)
196 #define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__)
197 #define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line)
198 #define MPASS4(ex, what, file, line) \
199 KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line))
201 extern struct lock_class lock_class_mtx_sleep;
202 extern struct lock_class lock_class_mtx_spin;
203 extern struct lock_class lock_class_sx;
205 void lock_init(struct lock_object *lock, struct lock_class *class,
206 const char *name, const char *type, int flags);
207 void lock_destroy(struct lock_object *lock);
208 void spinlock_enter(void);
209 void spinlock_exit(void);
210 void witness_init(struct lock_object *);
211 void witness_destroy(struct lock_object *);
212 int witness_defineorder(struct lock_object *, struct lock_object *);
213 void witness_checkorder(struct lock_object *, int, const char *, int);
214 void witness_lock(struct lock_object *, int, const char *, int);
215 void witness_upgrade(struct lock_object *, int, const char *, int);
216 void witness_downgrade(struct lock_object *, int, const char *, int);
217 void witness_unlock(struct lock_object *, int, const char *, int);
218 void witness_save(struct lock_object *, const char **, int *);
219 void witness_restore(struct lock_object *, const char *, int);
220 int witness_list_locks(struct lock_list_entry **);
221 int witness_warn(int, struct lock_object *, const char *, ...);
222 void witness_assert(struct lock_object *, int, const char *, int);
223 void witness_display_spinlock(struct lock_object *, struct thread *);
224 int witness_line(struct lock_object *);
225 const char *witness_file(struct lock_object *);
229 /* Flags for witness_warn(). */
230 #define WARN_GIANTOK 0x01 /* Giant is exempt from this check. */
231 #define WARN_PANIC 0x02 /* Panic if check fails. */
232 #define WARN_SLEEPOK 0x04 /* Sleepable locks are exempt from check. */
234 #define WITNESS_INIT(lock) \
237 #define WITNESS_DESTROY(lock) \
238 witness_destroy(lock)
240 #define WITNESS_CHECKORDER(lock, flags, file, line) \
241 witness_checkorder((lock), (flags), (file), (line))
243 #define WITNESS_DEFINEORDER(lock1, lock2) \
244 witness_defineorder((struct lock_object *)(lock1), \
245 (struct lock_object *)(lock2))
247 #define WITNESS_LOCK(lock, flags, file, line) \
248 witness_lock((lock), (flags), (file), (line))
250 #define WITNESS_UPGRADE(lock, flags, file, line) \
251 witness_upgrade((lock), (flags), (file), (line))
253 #define WITNESS_DOWNGRADE(lock, flags, file, line) \
254 witness_downgrade((lock), (flags), (file), (line))
256 #define WITNESS_UNLOCK(lock, flags, file, line) \
257 witness_unlock((lock), (flags), (file), (line))
259 #define WITNESS_WARN(flags, lock, fmt, ...) \
260 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
262 #define WITNESS_SAVE_DECL(n) \
263 const char * __CONCAT(n, __wf); \
264 int __CONCAT(n, __wl)
266 #define WITNESS_SAVE(lock, n) \
267 witness_save((lock), &__CONCAT(n, __wf), &__CONCAT(n, __wl))
269 #define WITNESS_RESTORE(lock, n) \
270 witness_restore((lock), __CONCAT(n, __wf), __CONCAT(n, __wl))
272 #define WITNESS_FILE(lock) \
275 #define WITNESS_LINE(lock) \
279 #define WITNESS_INIT(lock)
280 #define WITNESS_DESTROY(lock)
281 #define WITNESS_DEFINEORDER(lock1, lock2) 0
282 #define WITNESS_CHECKORDER(lock, flags, file, line)
283 #define WITNESS_LOCK(lock, flags, file, line)
284 #define WITNESS_UPGRADE(lock, flags, file, line)
285 #define WITNESS_DOWNGRADE(lock, flags, file, line)
286 #define WITNESS_UNLOCK(lock, flags, file, line)
287 #define WITNESS_WARN(flags, lock, fmt, ...)
288 #define WITNESS_SAVE_DECL(n)
289 #define WITNESS_SAVE(lock, n)
290 #define WITNESS_RESTORE(lock, n)
291 #define WITNESS_FILE(lock) ("?")
292 #define WITNESS_LINE(lock) (0)
296 * Helper macros to allow developers to add explicit lock order checks
297 * wherever they please without having to actually grab a lock to do so.
299 #define witness_check_mutex(m) \
300 WITNESS_CHECKORDER(&(m)->mtx_object, LOP_EXCLUSIVE, LOCK_FILE, \
303 #define witness_check_shared_sx(sx) \
304 WITNESS_CHECKORDER(&(sx)->sx_object, 0, LOCK_FILE, LOCK_LINE)
306 #define witness_check_exclusive_sx(sx) \
307 WITNESS_CHECKORDER(&(sx)->sx_object, LOP_EXCLUSIVE, LOCK_FILE, \
311 #endif /* _SYS_LOCK_H_ */