2 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
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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>
38 struct lock_list_entry;
42 * Lock classes. Each lock has a class which describes characteristics
43 * common to all types of locks of a given class.
45 * Spin locks in general must always protect against preemption, as it is
46 * an error to perform any type of context switch while holding a spin lock.
47 * Also, for an individual lock to be recursable, its class must allow
48 * recursion and the lock itself must explicitly allow recursion.
50 * The 'lc_ddb_show' function pointer is used to dump class-specific
51 * data for the 'show lock' DDB command. The 'lc_lock' and
52 * 'lc_unlock' function pointers are used in sleep(9) and cv_wait(9)
53 * to lock and unlock locks while blocking on a sleep queue. The
54 * return value of 'lc_unlock' will be passed to 'lc_lock' on resume
55 * to allow communication of state between the two routines.
61 void (*lc_assert)(struct lock_object *lock, int what);
62 void (*lc_ddb_show)(struct lock_object *lock);
63 void (*lc_lock)(struct lock_object *lock, int how);
64 int (*lc_unlock)(struct lock_object *lock);
67 #define LC_SLEEPLOCK 0x00000001 /* Sleep lock. */
68 #define LC_SPINLOCK 0x00000002 /* Spin lock. */
69 #define LC_SLEEPABLE 0x00000004 /* Sleeping allowed with this lock. */
70 #define LC_RECURSABLE 0x00000008 /* Locks of this type may recurse. */
71 #define LC_UPGRADABLE 0x00000010 /* Upgrades and downgrades permitted. */
73 #define LO_CLASSFLAGS 0x0000ffff /* Class specific flags. */
74 #define LO_INITIALIZED 0x00010000 /* Lock has been initialized. */
75 #define LO_WITNESS 0x00020000 /* Should witness monitor this lock. */
76 #define LO_QUIET 0x00040000 /* Don't log locking operations. */
77 #define LO_RECURSABLE 0x00080000 /* Lock may recurse. */
78 #define LO_SLEEPABLE 0x00100000 /* Lock may be held while sleeping. */
79 #define LO_UPGRADABLE 0x00200000 /* Lock may be upgraded/downgraded. */
80 #define LO_DUPOK 0x00400000 /* Don't check for duplicate acquires */
81 #define LO_CLASSMASK 0x0f000000 /* Class index bitmask. */
82 #define LO_NOPROFILE 0x10000000 /* Don't profile this lock */
85 * Lock classes are statically assigned an index into the gobal lock_classes
86 * array. Debugging code looks up the lock class for a given lock object
87 * by indexing the array.
89 #define LO_CLASSSHIFT 24
90 #define LO_CLASSINDEX(lock) ((((lock)->lo_flags) & LO_CLASSMASK) >> LO_CLASSSHIFT)
91 #define LOCK_CLASS(lock) (lock_classes[LO_CLASSINDEX((lock))])
92 #define LOCK_CLASS_MAX (LO_CLASSMASK >> LO_CLASSSHIFT)
95 * Option flags passed to lock operations that witness also needs to know
96 * about or that are generic across all locks.
98 #define LOP_NEWORDER 0x00000001 /* Define a new lock order. */
99 #define LOP_QUIET 0x00000002 /* Don't log locking operations. */
100 #define LOP_TRYLOCK 0x00000004 /* Don't check lock order. */
101 #define LOP_EXCLUSIVE 0x00000008 /* Exclusive lock. */
102 #define LOP_DUPOK 0x00000010 /* Don't check for duplicate acquires */
104 /* Flags passed to witness_assert. */
105 #define LA_MASKASSERT 0x000000ff /* Mask for witness defined asserts. */
106 #define LA_UNLOCKED 0x00000000 /* Lock is unlocked. */
107 #define LA_LOCKED 0x00000001 /* Lock is at least share locked. */
108 #define LA_SLOCKED 0x00000002 /* Lock is exactly share locked. */
109 #define LA_XLOCKED 0x00000004 /* Lock is exclusively locked. */
110 #define LA_RECURSED 0x00000008 /* Lock is recursed. */
111 #define LA_NOTRECURSED 0x00000010 /* Lock is not recursed. */
115 * If any of WITNESS, INVARIANTS, or KTR_LOCK KTR tracing has been enabled,
116 * then turn on LOCK_DEBUG. When this option is on, extra debugging
117 * facilities such as tracking the file and line number of lock operations
118 * are enabled. Also, mutex locking operations are not inlined to avoid
119 * bloat from all the extra debugging code. We also have to turn on all the
120 * calling conventions for this debugging code in modules so that modules can
121 * work with both debug and non-debug kernels.
123 #if defined(KLD_MODULE) || defined(WITNESS) || defined(INVARIANTS) || defined(INVARIANT_SUPPORT) || defined(KTR) || defined(LOCK_PROFILING)
130 * In the LOCK_DEBUG case, use the filename and line numbers for debugging
131 * operations. Otherwise, use default values to avoid the unneeded bloat.
134 #define LOCK_FILE __FILE__
135 #define LOCK_LINE __LINE__
137 #define LOCK_FILE NULL
142 * Macros for KTR_LOCK tracing.
144 * opname - name of this operation (LOCK/UNLOCK/SLOCK, etc.)
145 * lo - struct lock_object * for this lock
146 * flags - flags passed to the lock operation
147 * recurse - this locks recursion level (or 0 if class is not recursable)
148 * result - result of a try lock operation
152 #define LOCK_LOG_TEST(lo, flags) \
153 (((flags) & LOP_QUIET) == 0 && ((lo)->lo_flags & LO_QUIET) == 0)
155 #define LOCK_LOG_LOCK(opname, lo, flags, recurse, file, line) do { \
156 if (LOCK_LOG_TEST((lo), (flags))) \
157 CTR5(KTR_LOCK, opname " (%s) %s r = %d at %s:%d", \
158 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \
159 (u_int)(recurse), (file), (line)); \
162 #define LOCK_LOG_TRY(opname, lo, flags, result, file, line) do { \
163 if (LOCK_LOG_TEST((lo), (flags))) \
164 CTR5(KTR_LOCK, "TRY_" opname " (%s) %s result=%d at %s:%d",\
165 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \
166 (u_int)(result), (file), (line)); \
169 #define LOCK_LOG_INIT(lo, flags) do { \
170 if (LOCK_LOG_TEST((lo), (flags))) \
171 CTR4(KTR_LOCK, "%s: %p (%s) %s", __func__, (lo), \
172 LOCK_CLASS(lo)->lc_name, (lo)->lo_name); \
175 #define LOCK_LOG_DESTROY(lo, flags) LOCK_LOG_INIT(lo, flags)
177 #define lock_initalized(lo) ((lo)->lo_flags & LO_INITIALIZED)
180 * Helpful macros for quickly coming up with assertions with informative
183 #define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__)
184 #define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__)
185 #define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line)
186 #define MPASS4(ex, what, file, line) \
187 KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line))
189 extern struct lock_class lock_class_mtx_sleep;
190 extern struct lock_class lock_class_mtx_spin;
191 extern struct lock_class lock_class_sx;
192 extern struct lock_class lock_class_rw;
193 extern struct lock_class lock_class_rm;
194 extern struct lock_class lock_class_lockmgr;
196 extern struct lock_class *lock_classes[];
198 void lock_init(struct lock_object *, struct lock_class *,
199 const char *, const char *, int);
200 void lock_destroy(struct lock_object *);
201 void spinlock_enter(void);
202 void spinlock_exit(void);
203 void witness_init(struct lock_object *, const char *);
204 void witness_destroy(struct lock_object *);
205 int witness_defineorder(struct lock_object *, struct lock_object *);
206 void witness_checkorder(struct lock_object *, int, const char *, int,
207 struct lock_object *);
208 void witness_lock(struct lock_object *, int, const char *, int);
209 void witness_upgrade(struct lock_object *, int, const char *, int);
210 void witness_downgrade(struct lock_object *, int, const char *, int);
211 void witness_unlock(struct lock_object *, int, const char *, int);
212 void witness_save(struct lock_object *, const char **, int *);
213 void witness_restore(struct lock_object *, const char *, int);
214 int witness_list_locks(struct lock_list_entry **);
215 int witness_warn(int, struct lock_object *, const char *, ...);
216 void witness_assert(struct lock_object *, int, const char *, int);
217 void witness_display_spinlock(struct lock_object *, struct thread *);
218 int witness_line(struct lock_object *);
219 void witness_norelease(struct lock_object *);
220 void witness_releaseok(struct lock_object *);
221 const char *witness_file(struct lock_object *);
222 void witness_thread_exit(struct thread *);
226 /* Flags for witness_warn(). */
227 #define WARN_GIANTOK 0x01 /* Giant is exempt from this check. */
228 #define WARN_PANIC 0x02 /* Panic if check fails. */
229 #define WARN_SLEEPOK 0x04 /* Sleepable locks are exempt from check. */
231 #define WITNESS_INIT(lock, type) \
232 witness_init((lock), (type))
234 #define WITNESS_DESTROY(lock) \
235 witness_destroy(lock)
237 #define WITNESS_CHECKORDER(lock, flags, file, line, interlock) \
238 witness_checkorder((lock), (flags), (file), (line), (interlock))
240 #define WITNESS_DEFINEORDER(lock1, lock2) \
241 witness_defineorder((struct lock_object *)(lock1), \
242 (struct lock_object *)(lock2))
244 #define WITNESS_LOCK(lock, flags, file, line) \
245 witness_lock((lock), (flags), (file), (line))
247 #define WITNESS_UPGRADE(lock, flags, file, line) \
248 witness_upgrade((lock), (flags), (file), (line))
250 #define WITNESS_DOWNGRADE(lock, flags, file, line) \
251 witness_downgrade((lock), (flags), (file), (line))
253 #define WITNESS_UNLOCK(lock, flags, file, line) \
254 witness_unlock((lock), (flags), (file), (line))
256 #define WITNESS_CHECK(flags, lock, fmt, ...) \
257 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
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_NORELEASE(lock) \
273 witness_norelease(&(lock)->lock_object)
275 #define WITNESS_RELEASEOK(lock) \
276 witness_releaseok(&(lock)->lock_object)
278 #define WITNESS_FILE(lock) \
281 #define WITNESS_LINE(lock) \
285 #define WITNESS_INIT(lock, type)
286 #define WITNESS_DESTROY(lock)
287 #define WITNESS_DEFINEORDER(lock1, lock2) 0
288 #define WITNESS_CHECKORDER(lock, flags, file, line, interlock)
289 #define WITNESS_LOCK(lock, flags, file, line)
290 #define WITNESS_UPGRADE(lock, flags, file, line)
291 #define WITNESS_DOWNGRADE(lock, flags, file, line)
292 #define WITNESS_UNLOCK(lock, flags, file, line)
293 #define WITNESS_CHECK(flags, lock, fmt, ...) 0
294 #define WITNESS_WARN(flags, lock, fmt, ...)
295 #define WITNESS_SAVE_DECL(n)
296 #define WITNESS_SAVE(lock, n)
297 #define WITNESS_RESTORE(lock, n)
298 #define WITNESS_NORELEASE(lock)
299 #define WITNESS_RELEASEOK(lock)
300 #define WITNESS_FILE(lock) ("?")
301 #define WITNESS_LINE(lock) (0)
305 * Helper macros to allow developers to add explicit lock order checks
306 * wherever they please without having to actually grab a lock to do so.
308 #define witness_check(l) \
309 WITNESS_CHECKORDER(&(l)->lock_object, LOP_EXCLUSIVE, LOCK_FILE, \
312 #define witness_check_shared(l) \
313 WITNESS_CHECKORDER(&(l)->lock_object, 0, LOCK_FILE, LOCK_LINE, NULL)
316 #endif /* _SYS_LOCK_H_ */