2 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
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5 * modification, are permitted provided that the following conditions
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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>
37 #include <sys/_mutex.h>
41 #include <sys/lock_profile.h>
42 #include <sys/lockstat.h>
43 #include <machine/atomic.h>
44 #include <machine/cpufunc.h>
47 * Mutex types and options passed to mtx_init(). MTX_QUIET and MTX_DUPOK
48 * can also be passed in.
50 #define MTX_DEF 0x00000000 /* DEFAULT (sleep) lock */
51 #define MTX_SPIN 0x00000001 /* Spin lock (disables interrupts) */
52 #define MTX_RECURSE 0x00000004 /* Option: lock allowed to recurse */
53 #define MTX_NOWITNESS 0x00000008 /* Don't do any witness checking. */
54 #define MTX_NOPROFILE 0x00000020 /* Don't profile this lock */
55 #define MTX_NEW 0x00000040 /* Don't check for double-init */
58 * Option flags passed to certain lock/unlock routines, through the use
59 * of corresponding mtx_{lock,unlock}_flags() interface macros.
61 #define MTX_QUIET LOP_QUIET /* Don't log a mutex event */
62 #define MTX_DUPOK LOP_DUPOK /* Don't log a duplicate acquire */
65 * State bits kept in mutex->mtx_lock, for the DEFAULT lock type. None of this,
66 * with the exception of MTX_UNOWNED, applies to spin locks.
68 #define MTX_UNOWNED 0x00000000 /* Cookie for free mutex */
69 #define MTX_RECURSED 0x00000001 /* lock recursed (for MTX_DEF only) */
70 #define MTX_CONTESTED 0x00000002 /* lock contested (for MTX_DEF only) */
71 #define MTX_DESTROYED 0x00000004 /* lock destroyed */
72 #define MTX_FLAGMASK (MTX_RECURSED | MTX_CONTESTED | MTX_DESTROYED)
77 * NOTE: Functions prepended with `_' (underscore) are exported to other parts
78 * of the kernel via macros, thus allowing us to use the cpp LOCK_FILE
79 * and LOCK_LINE or for hiding the lock cookie crunching to the
80 * consumers. These functions should not be called directly by any
81 * code using the API. Their macros cover their functionality.
82 * Functions with a `_' suffix are the entrypoint for the common
83 * KPI covering both compat shims and fast path case. These can be
84 * used by consumers willing to pass options, file and line
85 * informations, in an option-independent way.
87 * [See below for descriptions]
90 void _mtx_init(volatile uintptr_t *c, const char *name, const char *type,
92 void _mtx_destroy(volatile uintptr_t *c);
93 void mtx_sysinit(void *arg);
94 int _mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF);
95 int _mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file,
97 void mutex_init(void);
99 void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, int opts,
100 const char *file, int line);
101 void __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v, int opts,
102 const char *file, int line);
104 void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v);
105 void __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v);
110 void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v, int opts,
111 const char *file, int line);
113 void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v);
116 void __mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file,
118 void __mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file,
120 void __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file,
122 int __mtx_trylock_spin_flags(volatile uintptr_t *c, int opts,
123 const char *file, int line);
124 void __mtx_unlock_spin_flags(volatile uintptr_t *c, int opts,
125 const char *file, int line);
126 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
127 void __mtx_assert(const volatile uintptr_t *c, int what, const char *file,
130 void thread_lock_flags_(struct thread *, int, const char *, int);
132 void _thread_lock(struct thread *td, int opts, const char *file, int line);
134 void _thread_lock(struct thread *);
137 #if defined(LOCK_PROFILING) || defined(KLD_MODULE)
138 #define thread_lock(tdp) \
139 thread_lock_flags_((tdp), 0, __FILE__, __LINE__)
141 #define thread_lock(tdp) \
142 _thread_lock((tdp), 0, __FILE__, __LINE__)
144 #define thread_lock(tdp) \
149 #define thread_lock_flags(tdp, opt) \
150 thread_lock_flags_((tdp), (opt), __FILE__, __LINE__)
152 #define thread_lock_flags(tdp, opt) \
156 #define thread_unlock(tdp) \
157 mtx_unlock_spin((tdp)->td_lock)
160 * Top-level macros to provide lock cookie once the actual mtx is passed.
161 * They will also prevent passing a malformed object to the mtx KPI by
162 * failing compilation as the mtx_lock reserved member will not be found.
164 #define mtx_init(m, n, t, o) \
165 _mtx_init(&(m)->mtx_lock, n, t, o)
166 #define mtx_destroy(m) \
167 _mtx_destroy(&(m)->mtx_lock)
168 #define mtx_trylock_flags_(m, o, f, l) \
169 _mtx_trylock_flags_(&(m)->mtx_lock, o, f, l)
171 #define _mtx_lock_sleep(m, v, o, f, l) \
172 __mtx_lock_sleep(&(m)->mtx_lock, v, o, f, l)
173 #define _mtx_unlock_sleep(m, v, o, f, l) \
174 __mtx_unlock_sleep(&(m)->mtx_lock, v, o, f, l)
176 #define _mtx_lock_sleep(m, v, o, f, l) \
177 __mtx_lock_sleep(&(m)->mtx_lock, v)
178 #define _mtx_unlock_sleep(m, v, o, f, l) \
179 __mtx_unlock_sleep(&(m)->mtx_lock, v)
183 #define _mtx_lock_spin(m, v, o, f, l) \
184 _mtx_lock_spin_cookie(&(m)->mtx_lock, v, o, f, l)
186 #define _mtx_lock_spin(m, v, o, f, l) \
187 _mtx_lock_spin_cookie(&(m)->mtx_lock, v)
190 #define _mtx_lock_flags(m, o, f, l) \
191 __mtx_lock_flags(&(m)->mtx_lock, o, f, l)
192 #define _mtx_unlock_flags(m, o, f, l) \
193 __mtx_unlock_flags(&(m)->mtx_lock, o, f, l)
194 #define _mtx_lock_spin_flags(m, o, f, l) \
195 __mtx_lock_spin_flags(&(m)->mtx_lock, o, f, l)
196 #define _mtx_trylock_spin_flags(m, o, f, l) \
197 __mtx_trylock_spin_flags(&(m)->mtx_lock, o, f, l)
198 #define _mtx_unlock_spin_flags(m, o, f, l) \
199 __mtx_unlock_spin_flags(&(m)->mtx_lock, o, f, l)
200 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
201 #define _mtx_assert(m, w, f, l) \
202 __mtx_assert(&(m)->mtx_lock, w, f, l)
205 #define mtx_recurse lock_object.lo_data
207 /* Very simple operations on mtx_lock. */
209 /* Try to obtain mtx_lock once. */
210 #define _mtx_obtain_lock(mp, tid) \
211 atomic_cmpset_acq_ptr(&(mp)->mtx_lock, MTX_UNOWNED, (tid))
213 #define _mtx_obtain_lock_fetch(mp, vp, tid) \
214 atomic_fcmpset_acq_ptr(&(mp)->mtx_lock, vp, (tid))
216 /* Try to release mtx_lock if it is unrecursed and uncontested. */
217 #define _mtx_release_lock(mp, tid) \
218 atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), MTX_UNOWNED)
220 /* Release mtx_lock quickly, assuming we own it. */
221 #define _mtx_release_lock_quick(mp) \
222 atomic_store_rel_ptr(&(mp)->mtx_lock, MTX_UNOWNED)
224 #define _mtx_release_lock_fetch(mp, vp) \
225 atomic_fcmpset_rel_ptr(&(mp)->mtx_lock, (vp), MTX_UNOWNED)
228 * Full lock operations that are suitable to be inlined in non-debug
229 * kernels. If the lock cannot be acquired or released trivially then
230 * the work is deferred to another function.
233 /* Lock a normal mutex. */
234 #define __mtx_lock(mp, tid, opts, file, line) do { \
235 uintptr_t _tid = (uintptr_t)(tid); \
236 uintptr_t _v = MTX_UNOWNED; \
238 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__acquire) ||\
239 !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \
240 _mtx_lock_sleep((mp), _v, (opts), (file), (line)); \
244 * Lock a spin mutex. For spinlocks, we handle recursion inline (it
245 * turns out that function calls can be significantly expensive on
246 * some architectures). Since spin locks are not _too_ common,
247 * inlining this code is not too big a deal.
250 #define __mtx_lock_spin(mp, tid, opts, file, line) do { \
251 uintptr_t _tid = (uintptr_t)(tid); \
252 uintptr_t _v = MTX_UNOWNED; \
255 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(spin__acquire) || \
256 !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \
257 _mtx_lock_spin((mp), _v, (opts), (file), (line)); \
259 #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \
260 uintptr_t _tid = (uintptr_t)(tid); \
264 if (((mp)->mtx_lock != MTX_UNOWNED || !_mtx_obtain_lock((mp), _tid))) {\
268 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, \
269 mp, 0, 0, file, line); \
275 #define __mtx_lock_spin(mp, tid, opts, file, line) do { \
276 uintptr_t _tid = (uintptr_t)(tid); \
279 if ((mp)->mtx_lock == _tid) \
280 (mp)->mtx_recurse++; \
282 KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \
283 (mp)->mtx_lock = _tid; \
286 #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \
287 uintptr_t _tid = (uintptr_t)(tid); \
291 if ((mp)->mtx_lock != MTX_UNOWNED) { \
295 (mp)->mtx_lock = _tid; \
302 /* Unlock a normal mutex. */
303 #define __mtx_unlock(mp, tid, opts, file, line) do { \
304 uintptr_t _v = (uintptr_t)(tid); \
306 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__release) ||\
307 !_mtx_release_lock_fetch((mp), &_v))) \
308 _mtx_unlock_sleep((mp), _v, (opts), (file), (line)); \
312 * Unlock a spin mutex. For spinlocks, we can handle everything
313 * inline, as it's pretty simple and a function call would be too
314 * expensive (at least on some architectures). Since spin locks are
315 * not _too_ common, inlining this code is not too big a deal.
317 * Since we always perform a spinlock_enter() when attempting to acquire a
318 * spin lock, we need to always perform a matching spinlock_exit() when
319 * releasing a spin lock. This includes the recursion cases.
322 #define __mtx_unlock_spin(mp) do { \
323 if (mtx_recursed((mp))) \
324 (mp)->mtx_recurse--; \
326 LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp); \
327 _mtx_release_lock_quick((mp)); \
332 #define __mtx_unlock_spin(mp) do { \
333 if (mtx_recursed((mp))) \
334 (mp)->mtx_recurse--; \
336 LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp); \
337 (mp)->mtx_lock = MTX_UNOWNED; \
344 * Exported lock manipulation interface.
346 * mtx_lock(m) locks MTX_DEF mutex `m'
348 * mtx_lock_spin(m) locks MTX_SPIN mutex `m'
350 * mtx_unlock(m) unlocks MTX_DEF mutex `m'
352 * mtx_unlock_spin(m) unlocks MTX_SPIN mutex `m'
354 * mtx_lock_spin_flags(m, opts) and mtx_lock_flags(m, opts) locks mutex `m'
355 * and passes option flags `opts' to the "hard" function, if required.
356 * With these routines, it is possible to pass flags such as MTX_QUIET
357 * to the appropriate lock manipulation routines.
359 * mtx_trylock(m) attempts to acquire MTX_DEF mutex `m' but doesn't sleep if
360 * it cannot. Rather, it returns 0 on failure and non-zero on success.
361 * It does NOT handle recursion as we assume that if a caller is properly
362 * using this part of the interface, he will know that the lock in question
365 * mtx_trylock_flags(m, opts) is used the same way as mtx_trylock() but accepts
366 * relevant option flags `opts.'
368 * mtx_trylock_spin(m) attempts to acquire MTX_SPIN mutex `m' but doesn't
369 * spin if it cannot. Rather, it returns 0 on failure and non-zero on
370 * success. It always returns failure for recursed lock attempts.
372 * mtx_initialized(m) returns non-zero if the lock `m' has been initialized.
374 * mtx_owned(m) returns non-zero if the current thread owns the lock `m'
376 * mtx_recursed(m) returns non-zero if the lock `m' is presently recursed.
378 #define mtx_lock(m) mtx_lock_flags((m), 0)
379 #define mtx_lock_spin(m) mtx_lock_spin_flags((m), 0)
380 #define mtx_trylock(m) mtx_trylock_flags((m), 0)
381 #define mtx_trylock_spin(m) mtx_trylock_spin_flags((m), 0)
382 #define mtx_unlock(m) mtx_unlock_flags((m), 0)
383 #define mtx_unlock_spin(m) mtx_unlock_spin_flags((m), 0)
387 struct mtx_pool *mtx_pool_create(const char *mtx_name, int pool_size, int opts);
388 void mtx_pool_destroy(struct mtx_pool **poolp);
389 struct mtx *mtx_pool_find(struct mtx_pool *pool, void *ptr);
390 struct mtx *mtx_pool_alloc(struct mtx_pool *pool);
391 #define mtx_pool_lock(pool, ptr) \
392 mtx_lock(mtx_pool_find((pool), (ptr)))
393 #define mtx_pool_lock_spin(pool, ptr) \
394 mtx_lock_spin(mtx_pool_find((pool), (ptr)))
395 #define mtx_pool_unlock(pool, ptr) \
396 mtx_unlock(mtx_pool_find((pool), (ptr)))
397 #define mtx_pool_unlock_spin(pool, ptr) \
398 mtx_unlock_spin(mtx_pool_find((pool), (ptr)))
401 * mtxpool_sleep is a general purpose pool of sleep mutexes.
403 extern struct mtx_pool *mtxpool_sleep;
406 #error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/mutex.h>
408 #if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE)
409 #define mtx_lock_flags_(m, opts, file, line) \
410 _mtx_lock_flags((m), (opts), (file), (line))
411 #define mtx_unlock_flags_(m, opts, file, line) \
412 _mtx_unlock_flags((m), (opts), (file), (line))
413 #define mtx_lock_spin_flags_(m, opts, file, line) \
414 _mtx_lock_spin_flags((m), (opts), (file), (line))
415 #define mtx_trylock_spin_flags_(m, opts, file, line) \
416 _mtx_trylock_spin_flags((m), (opts), (file), (line))
417 #define mtx_unlock_spin_flags_(m, opts, file, line) \
418 _mtx_unlock_spin_flags((m), (opts), (file), (line))
419 #else /* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */
420 #define mtx_lock_flags_(m, opts, file, line) \
421 __mtx_lock((m), curthread, (opts), (file), (line))
422 #define mtx_unlock_flags_(m, opts, file, line) \
423 __mtx_unlock((m), curthread, (opts), (file), (line))
424 #define mtx_lock_spin_flags_(m, opts, file, line) \
425 __mtx_lock_spin((m), curthread, (opts), (file), (line))
426 #define mtx_trylock_spin_flags_(m, opts, file, line) \
427 __mtx_trylock_spin((m), curthread, (opts), (file), (line))
428 #define mtx_unlock_spin_flags_(m, opts, file, line) \
429 __mtx_unlock_spin((m))
430 #endif /* LOCK_DEBUG > 0 || MUTEX_NOINLINE */
433 #define mtx_assert_(m, what, file, line) \
434 _mtx_assert((m), (what), (file), (line))
436 #define GIANT_REQUIRED mtx_assert_(&Giant, MA_OWNED, __FILE__, __LINE__)
438 #else /* INVARIANTS */
439 #define mtx_assert_(m, what, file, line) (void)0
440 #define GIANT_REQUIRED
441 #endif /* INVARIANTS */
443 #define mtx_lock_flags(m, opts) \
444 mtx_lock_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
445 #define mtx_unlock_flags(m, opts) \
446 mtx_unlock_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
447 #define mtx_lock_spin_flags(m, opts) \
448 mtx_lock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
449 #define mtx_unlock_spin_flags(m, opts) \
450 mtx_unlock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
451 #define mtx_trylock_flags(m, opts) \
452 mtx_trylock_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
453 #define mtx_trylock_spin_flags(m, opts) \
454 mtx_trylock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
455 #define mtx_assert(m, what) \
456 mtx_assert_((m), (what), __FILE__, __LINE__)
458 #define mtx_sleep(chan, mtx, pri, wmesg, timo) \
459 _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), \
460 tick_sbt * (timo), 0, C_HARDCLOCK)
462 #define MTX_READ_VALUE(m) ((m)->mtx_lock)
464 #define mtx_initialized(m) lock_initialized(&(m)->lock_object)
466 #define lv_mtx_owner(v) ((struct thread *)((v) & ~MTX_FLAGMASK))
468 #define mtx_owner(m) lv_mtx_owner(MTX_READ_VALUE(m))
470 #define mtx_owned(m) (mtx_owner(m) == curthread)
472 #define mtx_recursed(m) ((m)->mtx_recurse != 0)
474 #define mtx_name(m) ((m)->lock_object.lo_name)
479 extern struct mtx Giant;
480 extern struct mtx blocked_lock;
483 * Giant lock manipulation and clean exit macros.
484 * Used to replace return with an exit Giant and return.
486 * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT()
487 * The #ifndef is to allow lint-like tools to redefine DROP_GIANT.
490 #define DROP_GIANT() \
493 WITNESS_SAVE_DECL(Giant); \
495 if (mtx_owned(&Giant)) { \
496 WITNESS_SAVE(&Giant.lock_object, Giant); \
497 for (_giantcnt = 0; mtx_owned(&Giant) && \
498 !SCHEDULER_STOPPED(); _giantcnt++) \
499 mtx_unlock(&Giant); \
502 #define PICKUP_GIANT() \
503 PARTIAL_PICKUP_GIANT(); \
506 #define PARTIAL_PICKUP_GIANT() \
507 mtx_assert(&Giant, MA_NOTOWNED); \
508 if (_giantcnt > 0) { \
509 while (_giantcnt--) \
511 WITNESS_RESTORE(&Giant.lock_object, Giant); \
521 #define MTX_SYSINIT(name, mtx, desc, opts) \
522 static struct mtx_args name##_args = { \
527 SYSINIT(name##_mtx_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \
528 mtx_sysinit, &name##_args); \
529 SYSUNINIT(name##_mtx_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \
530 _mtx_destroy, __DEVOLATILE(void *, &(mtx)->mtx_lock))
533 * The INVARIANTS-enabled mtx_assert() functionality.
535 * The constants need to be defined for INVARIANT_SUPPORT infrastructure
536 * support as _mtx_assert() itself uses them and the latter implies that
537 * _mtx_assert() must build.
539 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
540 #define MA_OWNED LA_XLOCKED
541 #define MA_NOTOWNED LA_UNLOCKED
542 #define MA_RECURSED LA_RECURSED
543 #define MA_NOTRECURSED LA_NOTRECURSED
547 * Common lock type names.
549 #define MTX_NETWORK_LOCK "network driver"
552 #endif /* _SYS_MUTEX_H_ */