4 * Linux wait queue related types and methods
6 #include <linux/list.h>
7 #include <linux/stddef.h>
8 #include <linux/spinlock.h>
9 #include <asm/current.h>
10 #include <uapi/linux/wait.h>
12 typedef struct __wait_queue wait_queue_t
;
13 typedef int (*wait_queue_func_t
)(wait_queue_t
*wait
, unsigned mode
, int flags
, void *key
);
14 int default_wake_function(wait_queue_t
*wait
, unsigned mode
, int flags
, void *key
);
18 #define WQ_FLAG_EXCLUSIVE 0x01
20 wait_queue_func_t func
;
21 struct list_head task_list
;
27 #define WAIT_ATOMIC_T_BIT_NR -1
30 struct wait_bit_queue
{
31 struct wait_bit_key key
;
35 struct __wait_queue_head
{
37 struct list_head task_list
;
39 typedef struct __wait_queue_head wait_queue_head_t
;
44 * Macros for declaration and initialisaton of the datatypes
47 #define __WAITQUEUE_INITIALIZER(name, tsk) { \
49 .func = default_wake_function, \
50 .task_list = { NULL, NULL } }
52 #define DECLARE_WAITQUEUE(name, tsk) \
53 wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
55 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
56 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
57 .task_list = { &(name).task_list, &(name).task_list } }
59 #define DECLARE_WAIT_QUEUE_HEAD(name) \
60 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
62 #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
63 { .flags = word, .bit_nr = bit, }
65 #define __WAIT_ATOMIC_T_KEY_INITIALIZER(p) \
66 { .flags = p, .bit_nr = WAIT_ATOMIC_T_BIT_NR, }
68 extern void __init_waitqueue_head(wait_queue_head_t
*q
, const char *name
, struct lock_class_key
*);
70 #define init_waitqueue_head(q) \
72 static struct lock_class_key __key; \
74 __init_waitqueue_head((q), #q, &__key); \
78 # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
79 ({ init_waitqueue_head(&name); name; })
80 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
81 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
83 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
86 static inline void init_waitqueue_entry(wait_queue_t
*q
, struct task_struct
*p
)
90 q
->func
= default_wake_function
;
94 init_waitqueue_func_entry(wait_queue_t
*q
, wait_queue_func_t func
)
101 static inline int waitqueue_active(wait_queue_head_t
*q
)
103 return !list_empty(&q
->task_list
);
106 extern void add_wait_queue(wait_queue_head_t
*q
, wait_queue_t
*wait
);
107 extern void add_wait_queue_exclusive(wait_queue_head_t
*q
, wait_queue_t
*wait
);
108 extern void remove_wait_queue(wait_queue_head_t
*q
, wait_queue_t
*wait
);
110 static inline void __add_wait_queue(wait_queue_head_t
*head
, wait_queue_t
*new)
112 list_add(&new->task_list
, &head
->task_list
);
116 * Used for wake-one threads:
119 __add_wait_queue_exclusive(wait_queue_head_t
*q
, wait_queue_t
*wait
)
121 wait
->flags
|= WQ_FLAG_EXCLUSIVE
;
122 __add_wait_queue(q
, wait
);
125 static inline void __add_wait_queue_tail(wait_queue_head_t
*head
,
128 list_add_tail(&new->task_list
, &head
->task_list
);
132 __add_wait_queue_tail_exclusive(wait_queue_head_t
*q
, wait_queue_t
*wait
)
134 wait
->flags
|= WQ_FLAG_EXCLUSIVE
;
135 __add_wait_queue_tail(q
, wait
);
139 __remove_wait_queue(wait_queue_head_t
*head
, wait_queue_t
*old
)
141 list_del(&old
->task_list
);
144 void __wake_up(wait_queue_head_t
*q
, unsigned int mode
, int nr
, void *key
);
145 void __wake_up_locked_key(wait_queue_head_t
*q
, unsigned int mode
, void *key
);
146 void __wake_up_sync_key(wait_queue_head_t
*q
, unsigned int mode
, int nr
, void *key
);
147 void __wake_up_locked(wait_queue_head_t
*q
, unsigned int mode
, int nr
);
148 void __wake_up_sync(wait_queue_head_t
*q
, unsigned int mode
, int nr
);
149 void __wake_up_bit(wait_queue_head_t
*, void *, int);
150 int __wait_on_bit(wait_queue_head_t
*, struct wait_bit_queue
*, int (*)(void *), unsigned);
151 int __wait_on_bit_lock(wait_queue_head_t
*, struct wait_bit_queue
*, int (*)(void *), unsigned);
152 void wake_up_bit(void *, int);
153 void wake_up_atomic_t(atomic_t
*);
154 int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
155 int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
156 int out_of_line_wait_on_atomic_t(atomic_t
*, int (*)(atomic_t
*), unsigned);
157 wait_queue_head_t
*bit_waitqueue(void *, int);
159 #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
160 #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
161 #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
162 #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
163 #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
165 #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
166 #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
167 #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
168 #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
171 * Wakeup macros to be used to report events to the targets.
173 #define wake_up_poll(x, m) \
174 __wake_up(x, TASK_NORMAL, 1, (void *) (m))
175 #define wake_up_locked_poll(x, m) \
176 __wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
177 #define wake_up_interruptible_poll(x, m) \
178 __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
179 #define wake_up_interruptible_sync_poll(x, m) \
180 __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
182 #define ___wait_cond_timeout(condition) \
184 bool __cond = (condition); \
185 if (__cond && !__ret) \
190 #define ___wait_is_interruptible(state) \
191 (!__builtin_constant_p(state) || \
192 state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \
194 #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \
197 wait_queue_t __wait; \
200 INIT_LIST_HEAD(&__wait.task_list); \
202 __wait.flags = WQ_FLAG_EXCLUSIVE; \
207 long __int = prepare_to_wait_event(&wq, &__wait, state);\
212 if (___wait_is_interruptible(state) && __int) { \
215 abort_exclusive_wait(&wq, &__wait, \
224 finish_wait(&wq, &__wait); \
228 #define __wait_event(wq, condition) \
229 (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
233 * wait_event - sleep until a condition gets true
234 * @wq: the waitqueue to wait on
235 * @condition: a C expression for the event to wait for
237 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
238 * @condition evaluates to true. The @condition is checked each time
239 * the waitqueue @wq is woken up.
241 * wake_up() has to be called after changing any variable that could
242 * change the result of the wait condition.
244 #define wait_event(wq, condition) \
248 __wait_event(wq, condition); \
251 #define __wait_event_timeout(wq, condition, timeout) \
252 ___wait_event(wq, ___wait_cond_timeout(condition), \
253 TASK_UNINTERRUPTIBLE, 0, timeout, \
254 __ret = schedule_timeout(__ret))
257 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
258 * @wq: the waitqueue to wait on
259 * @condition: a C expression for the event to wait for
260 * @timeout: timeout, in jiffies
262 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
263 * @condition evaluates to true. The @condition is checked each time
264 * the waitqueue @wq is woken up.
266 * wake_up() has to be called after changing any variable that could
267 * change the result of the wait condition.
269 * The function returns 0 if the @timeout elapsed, or the remaining
270 * jiffies (at least 1) if the @condition evaluated to %true before
271 * the @timeout elapsed.
273 #define wait_event_timeout(wq, condition, timeout) \
275 long __ret = timeout; \
276 if (!___wait_cond_timeout(condition)) \
277 __ret = __wait_event_timeout(wq, condition, timeout); \
281 #define __wait_event_interruptible(wq, condition) \
282 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
286 * wait_event_interruptible - sleep until a condition gets true
287 * @wq: the waitqueue to wait on
288 * @condition: a C expression for the event to wait for
290 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
291 * @condition evaluates to true or a signal is received.
292 * The @condition is checked each time the waitqueue @wq is woken up.
294 * wake_up() has to be called after changing any variable that could
295 * change the result of the wait condition.
297 * The function will return -ERESTARTSYS if it was interrupted by a
298 * signal and 0 if @condition evaluated to true.
300 #define wait_event_interruptible(wq, condition) \
304 __ret = __wait_event_interruptible(wq, condition); \
308 #define __wait_event_interruptible_timeout(wq, condition, timeout) \
309 ___wait_event(wq, ___wait_cond_timeout(condition), \
310 TASK_INTERRUPTIBLE, 0, timeout, \
311 __ret = schedule_timeout(__ret))
314 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
315 * @wq: the waitqueue to wait on
316 * @condition: a C expression for the event to wait for
317 * @timeout: timeout, in jiffies
319 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
320 * @condition evaluates to true or a signal is received.
321 * The @condition is checked each time the waitqueue @wq is woken up.
323 * wake_up() has to be called after changing any variable that could
324 * change the result of the wait condition.
327 * 0 if the @timeout elapsed, -%ERESTARTSYS if it was interrupted by
328 * a signal, or the remaining jiffies (at least 1) if the @condition
329 * evaluated to %true before the @timeout elapsed.
331 #define wait_event_interruptible_timeout(wq, condition, timeout) \
333 long __ret = timeout; \
334 if (!___wait_cond_timeout(condition)) \
335 __ret = __wait_event_interruptible_timeout(wq, \
336 condition, timeout); \
340 #define __wait_event_hrtimeout(wq, condition, timeout, state) \
343 struct hrtimer_sleeper __t; \
345 hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \
347 hrtimer_init_sleeper(&__t, current); \
348 if ((timeout).tv64 != KTIME_MAX) \
349 hrtimer_start_range_ns(&__t.timer, timeout, \
350 current->timer_slack_ns, \
353 __ret = ___wait_event(wq, condition, state, 0, 0, \
360 hrtimer_cancel(&__t.timer); \
361 destroy_hrtimer_on_stack(&__t.timer); \
366 * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
367 * @wq: the waitqueue to wait on
368 * @condition: a C expression for the event to wait for
369 * @timeout: timeout, as a ktime_t
371 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
372 * @condition evaluates to true or a signal is received.
373 * The @condition is checked each time the waitqueue @wq is woken up.
375 * wake_up() has to be called after changing any variable that could
376 * change the result of the wait condition.
378 * The function returns 0 if @condition became true, or -ETIME if the timeout
381 #define wait_event_hrtimeout(wq, condition, timeout) \
385 __ret = __wait_event_hrtimeout(wq, condition, timeout, \
386 TASK_UNINTERRUPTIBLE); \
391 * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
392 * @wq: the waitqueue to wait on
393 * @condition: a C expression for the event to wait for
394 * @timeout: timeout, as a ktime_t
396 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
397 * @condition evaluates to true or a signal is received.
398 * The @condition is checked each time the waitqueue @wq is woken up.
400 * wake_up() has to be called after changing any variable that could
401 * change the result of the wait condition.
403 * The function returns 0 if @condition became true, -ERESTARTSYS if it was
404 * interrupted by a signal, or -ETIME if the timeout elapsed.
406 #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
410 __ret = __wait_event_hrtimeout(wq, condition, timeout, \
411 TASK_INTERRUPTIBLE); \
415 #define __wait_event_interruptible_exclusive(wq, condition) \
416 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
419 #define wait_event_interruptible_exclusive(wq, condition) \
423 __ret = __wait_event_interruptible_exclusive(wq, condition);\
428 #define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
431 DEFINE_WAIT(__wait); \
433 __wait.flags |= WQ_FLAG_EXCLUSIVE; \
435 if (likely(list_empty(&__wait.task_list))) \
436 __add_wait_queue_tail(&(wq), &__wait); \
437 set_current_state(TASK_INTERRUPTIBLE); \
438 if (signal_pending(current)) { \
439 __ret = -ERESTARTSYS; \
443 spin_unlock_irq(&(wq).lock); \
445 spin_unlock(&(wq).lock); \
448 spin_lock_irq(&(wq).lock); \
450 spin_lock(&(wq).lock); \
451 } while (!(condition)); \
452 __remove_wait_queue(&(wq), &__wait); \
453 __set_current_state(TASK_RUNNING); \
459 * wait_event_interruptible_locked - sleep until a condition gets true
460 * @wq: the waitqueue to wait on
461 * @condition: a C expression for the event to wait for
463 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
464 * @condition evaluates to true or a signal is received.
465 * The @condition is checked each time the waitqueue @wq is woken up.
467 * It must be called with wq.lock being held. This spinlock is
468 * unlocked while sleeping but @condition testing is done while lock
469 * is held and when this macro exits the lock is held.
471 * The lock is locked/unlocked using spin_lock()/spin_unlock()
472 * functions which must match the way they are locked/unlocked outside
475 * wake_up_locked() has to be called after changing any variable that could
476 * change the result of the wait condition.
478 * The function will return -ERESTARTSYS if it was interrupted by a
479 * signal and 0 if @condition evaluated to true.
481 #define wait_event_interruptible_locked(wq, condition) \
483 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))
486 * wait_event_interruptible_locked_irq - sleep until a condition gets true
487 * @wq: the waitqueue to wait on
488 * @condition: a C expression for the event to wait for
490 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
491 * @condition evaluates to true or a signal is received.
492 * The @condition is checked each time the waitqueue @wq is woken up.
494 * It must be called with wq.lock being held. This spinlock is
495 * unlocked while sleeping but @condition testing is done while lock
496 * is held and when this macro exits the lock is held.
498 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
499 * functions which must match the way they are locked/unlocked outside
502 * wake_up_locked() has to be called after changing any variable that could
503 * change the result of the wait condition.
505 * The function will return -ERESTARTSYS if it was interrupted by a
506 * signal and 0 if @condition evaluated to true.
508 #define wait_event_interruptible_locked_irq(wq, condition) \
510 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1))
513 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
514 * @wq: the waitqueue to wait on
515 * @condition: a C expression for the event to wait for
517 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
518 * @condition evaluates to true or a signal is received.
519 * The @condition is checked each time the waitqueue @wq is woken up.
521 * It must be called with wq.lock being held. This spinlock is
522 * unlocked while sleeping but @condition testing is done while lock
523 * is held and when this macro exits the lock is held.
525 * The lock is locked/unlocked using spin_lock()/spin_unlock()
526 * functions which must match the way they are locked/unlocked outside
529 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
530 * set thus when other process waits process on the list if this
531 * process is awaken further processes are not considered.
533 * wake_up_locked() has to be called after changing any variable that could
534 * change the result of the wait condition.
536 * The function will return -ERESTARTSYS if it was interrupted by a
537 * signal and 0 if @condition evaluated to true.
539 #define wait_event_interruptible_exclusive_locked(wq, condition) \
541 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0))
544 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
545 * @wq: the waitqueue to wait on
546 * @condition: a C expression for the event to wait for
548 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
549 * @condition evaluates to true or a signal is received.
550 * The @condition is checked each time the waitqueue @wq is woken up.
552 * It must be called with wq.lock being held. This spinlock is
553 * unlocked while sleeping but @condition testing is done while lock
554 * is held and when this macro exits the lock is held.
556 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
557 * functions which must match the way they are locked/unlocked outside
560 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
561 * set thus when other process waits process on the list if this
562 * process is awaken further processes are not considered.
564 * wake_up_locked() has to be called after changing any variable that could
565 * change the result of the wait condition.
567 * The function will return -ERESTARTSYS if it was interrupted by a
568 * signal and 0 if @condition evaluated to true.
570 #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
572 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
575 #define __wait_event_killable(wq, condition) \
576 ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
579 * wait_event_killable - sleep until a condition gets true
580 * @wq: the waitqueue to wait on
581 * @condition: a C expression for the event to wait for
583 * The process is put to sleep (TASK_KILLABLE) until the
584 * @condition evaluates to true or a signal is received.
585 * The @condition is checked each time the waitqueue @wq is woken up.
587 * wake_up() has to be called after changing any variable that could
588 * change the result of the wait condition.
590 * The function will return -ERESTARTSYS if it was interrupted by a
591 * signal and 0 if @condition evaluated to true.
593 #define wait_event_killable(wq, condition) \
597 __ret = __wait_event_killable(wq, condition); \
602 #define __wait_event_lock_irq(wq, condition, lock, cmd) \
603 (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
604 spin_unlock_irq(&lock); \
607 spin_lock_irq(&lock))
610 * wait_event_lock_irq_cmd - sleep until a condition gets true. The
611 * condition is checked under the lock. This
612 * is expected to be called with the lock
614 * @wq: the waitqueue to wait on
615 * @condition: a C expression for the event to wait for
616 * @lock: a locked spinlock_t, which will be released before cmd
617 * and schedule() and reacquired afterwards.
618 * @cmd: a command which is invoked outside the critical section before
621 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
622 * @condition evaluates to true. The @condition is checked each time
623 * the waitqueue @wq is woken up.
625 * wake_up() has to be called after changing any variable that could
626 * change the result of the wait condition.
628 * This is supposed to be called while holding the lock. The lock is
629 * dropped before invoking the cmd and going to sleep and is reacquired
632 #define wait_event_lock_irq_cmd(wq, condition, lock, cmd) \
636 __wait_event_lock_irq(wq, condition, lock, cmd); \
640 * wait_event_lock_irq - sleep until a condition gets true. The
641 * condition is checked under the lock. This
642 * is expected to be called with the lock
644 * @wq: the waitqueue to wait on
645 * @condition: a C expression for the event to wait for
646 * @lock: a locked spinlock_t, which will be released before schedule()
647 * and reacquired afterwards.
649 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
650 * @condition evaluates to true. The @condition is checked each time
651 * the waitqueue @wq is woken up.
653 * wake_up() has to be called after changing any variable that could
654 * change the result of the wait condition.
656 * This is supposed to be called while holding the lock. The lock is
657 * dropped before going to sleep and is reacquired afterwards.
659 #define wait_event_lock_irq(wq, condition, lock) \
663 __wait_event_lock_irq(wq, condition, lock, ); \
667 #define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \
668 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
669 spin_unlock_irq(&lock); \
672 spin_lock_irq(&lock))
675 * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
676 * The condition is checked under the lock. This is expected to
677 * be called with the lock taken.
678 * @wq: the waitqueue to wait on
679 * @condition: a C expression for the event to wait for
680 * @lock: a locked spinlock_t, which will be released before cmd and
681 * schedule() and reacquired afterwards.
682 * @cmd: a command which is invoked outside the critical section before
685 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
686 * @condition evaluates to true or a signal is received. The @condition is
687 * checked each time the waitqueue @wq is woken up.
689 * wake_up() has to be called after changing any variable that could
690 * change the result of the wait condition.
692 * This is supposed to be called while holding the lock. The lock is
693 * dropped before invoking the cmd and going to sleep and is reacquired
696 * The macro will return -ERESTARTSYS if it was interrupted by a signal
697 * and 0 if @condition evaluated to true.
699 #define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \
703 __ret = __wait_event_interruptible_lock_irq(wq, \
704 condition, lock, cmd); \
709 * wait_event_interruptible_lock_irq - sleep until a condition gets true.
710 * The condition is checked under the lock. This is expected
711 * to be called with the lock taken.
712 * @wq: the waitqueue to wait on
713 * @condition: a C expression for the event to wait for
714 * @lock: a locked spinlock_t, which will be released before schedule()
715 * and reacquired afterwards.
717 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
718 * @condition evaluates to true or signal is received. The @condition is
719 * checked each time the waitqueue @wq is woken up.
721 * wake_up() has to be called after changing any variable that could
722 * change the result of the wait condition.
724 * This is supposed to be called while holding the lock. The lock is
725 * dropped before going to sleep and is reacquired afterwards.
727 * The macro will return -ERESTARTSYS if it was interrupted by a signal
728 * and 0 if @condition evaluated to true.
730 #define wait_event_interruptible_lock_irq(wq, condition, lock) \
734 __ret = __wait_event_interruptible_lock_irq(wq, \
739 #define __wait_event_interruptible_lock_irq_timeout(wq, condition, \
741 ___wait_event(wq, ___wait_cond_timeout(condition), \
742 TASK_INTERRUPTIBLE, 0, timeout, \
743 spin_unlock_irq(&lock); \
744 __ret = schedule_timeout(__ret); \
745 spin_lock_irq(&lock));
748 * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
749 * true or a timeout elapses. The condition is checked under
750 * the lock. This is expected to be called with the lock taken.
751 * @wq: the waitqueue to wait on
752 * @condition: a C expression for the event to wait for
753 * @lock: a locked spinlock_t, which will be released before schedule()
754 * and reacquired afterwards.
755 * @timeout: timeout, in jiffies
757 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
758 * @condition evaluates to true or signal is received. The @condition is
759 * checked each time the waitqueue @wq is woken up.
761 * wake_up() has to be called after changing any variable that could
762 * change the result of the wait condition.
764 * This is supposed to be called while holding the lock. The lock is
765 * dropped before going to sleep and is reacquired afterwards.
767 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
768 * was interrupted by a signal, and the remaining jiffies otherwise
769 * if the condition evaluated to true before the timeout elapsed.
771 #define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \
774 long __ret = timeout; \
775 if (!___wait_cond_timeout(condition)) \
776 __ret = __wait_event_interruptible_lock_irq_timeout( \
777 wq, condition, lock, timeout); \
783 * These are the old interfaces to sleep waiting for an event.
784 * They are racy. DO NOT use them, use the wait_event* interfaces above.
785 * We plan to remove these interfaces.
787 extern void sleep_on(wait_queue_head_t
*q
);
788 extern long sleep_on_timeout(wait_queue_head_t
*q
, signed long timeout
);
789 extern void interruptible_sleep_on(wait_queue_head_t
*q
);
790 extern long interruptible_sleep_on_timeout(wait_queue_head_t
*q
, signed long timeout
);
793 * Waitqueues which are removed from the waitqueue_head at wakeup time
795 void prepare_to_wait(wait_queue_head_t
*q
, wait_queue_t
*wait
, int state
);
796 void prepare_to_wait_exclusive(wait_queue_head_t
*q
, wait_queue_t
*wait
, int state
);
797 long prepare_to_wait_event(wait_queue_head_t
*q
, wait_queue_t
*wait
, int state
);
798 void finish_wait(wait_queue_head_t
*q
, wait_queue_t
*wait
);
799 void abort_exclusive_wait(wait_queue_head_t
*q
, wait_queue_t
*wait
, unsigned int mode
, void *key
);
800 int autoremove_wake_function(wait_queue_t
*wait
, unsigned mode
, int sync
, void *key
);
801 int wake_bit_function(wait_queue_t
*wait
, unsigned mode
, int sync
, void *key
);
803 #define DEFINE_WAIT_FUNC(name, function) \
804 wait_queue_t name = { \
805 .private = current, \
807 .task_list = LIST_HEAD_INIT((name).task_list), \
810 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
812 #define DEFINE_WAIT_BIT(name, word, bit) \
813 struct wait_bit_queue name = { \
814 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
816 .private = current, \
817 .func = wake_bit_function, \
819 LIST_HEAD_INIT((name).wait.task_list), \
823 #define init_wait(wait) \
825 (wait)->private = current; \
826 (wait)->func = autoremove_wake_function; \
827 INIT_LIST_HEAD(&(wait)->task_list); \
832 * wait_on_bit - wait for a bit to be cleared
833 * @word: the word being waited on, a kernel virtual address
834 * @bit: the bit of the word being waited on
835 * @action: the function used to sleep, which may take special actions
836 * @mode: the task state to sleep in
838 * There is a standard hashed waitqueue table for generic use. This
839 * is the part of the hashtable's accessor API that waits on a bit.
840 * For instance, if one were to have waiters on a bitflag, one would
841 * call wait_on_bit() in threads waiting for the bit to clear.
842 * One uses wait_on_bit() where one is waiting for the bit to clear,
843 * but has no intention of setting it.
846 wait_on_bit(void *word
, int bit
, int (*action
)(void *), unsigned mode
)
848 if (!test_bit(bit
, word
))
850 return out_of_line_wait_on_bit(word
, bit
, action
, mode
);
854 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
855 * @word: the word being waited on, a kernel virtual address
856 * @bit: the bit of the word being waited on
857 * @action: the function used to sleep, which may take special actions
858 * @mode: the task state to sleep in
860 * There is a standard hashed waitqueue table for generic use. This
861 * is the part of the hashtable's accessor API that waits on a bit
862 * when one intends to set it, for instance, trying to lock bitflags.
863 * For instance, if one were to have waiters trying to set bitflag
864 * and waiting for it to clear before setting it, one would call
865 * wait_on_bit() in threads waiting to be able to set the bit.
866 * One uses wait_on_bit_lock() where one is waiting for the bit to
867 * clear with the intention of setting it, and when done, clearing it.
870 wait_on_bit_lock(void *word
, int bit
, int (*action
)(void *), unsigned mode
)
872 if (!test_and_set_bit(bit
, word
))
874 return out_of_line_wait_on_bit_lock(word
, bit
, action
, mode
);
878 * wait_on_atomic_t - Wait for an atomic_t to become 0
879 * @val: The atomic value being waited on, a kernel virtual address
880 * @action: the function used to sleep, which may take special actions
881 * @mode: the task state to sleep in
883 * Wait for an atomic_t to become 0. We abuse the bit-wait waitqueue table for
884 * the purpose of getting a waitqueue, but we set the key to a bit number
885 * outside of the target 'word'.
888 int wait_on_atomic_t(atomic_t
*val
, int (*action
)(atomic_t
*), unsigned mode
)
890 if (atomic_read(val
) == 0)
892 return out_of_line_wait_on_atomic_t(val
, action
, mode
);
895 #endif /* _LINUX_WAIT_H */