4 #define WNOHANG 0x00000001
5 #define WUNTRACED 0x00000002
6 #define WSTOPPED WUNTRACED
7 #define WEXITED 0x00000004
8 #define WCONTINUED 0x00000008
9 #define WNOWAIT 0x01000000 /* Don't reap, just poll status. */
11 #define __WNOTHREAD 0x20000000 /* Don't wait on children of other threads in this group */
12 #define __WALL 0x40000000 /* Wait on all children, regardless of type */
13 #define __WCLONE 0x80000000 /* Wait only on non-SIGCHLD children */
15 /* First argument to waitid: */
22 #include <linux/list.h>
23 #include <linux/stddef.h>
24 #include <linux/spinlock.h>
25 #include <asm/system.h>
26 #include <asm/current.h>
28 typedef struct __wait_queue wait_queue_t;
29 typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
30 int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
34 #define WQ_FLAG_EXCLUSIVE 0x01
36 wait_queue_func_t func;
37 struct list_head task_list;
45 struct wait_bit_queue {
46 struct wait_bit_key key;
50 struct __wait_queue_head {
52 struct list_head task_list;
54 typedef struct __wait_queue_head wait_queue_head_t;
59 * Macros for declaration and initialisaton of the datatypes
62 #define __WAITQUEUE_INITIALIZER(name, tsk) { \
64 .func = default_wake_function, \
65 .task_list = { NULL, NULL } }
67 #define DECLARE_WAITQUEUE(name, tsk) \
68 wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
70 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
71 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
72 .task_list = { &(name).task_list, &(name).task_list } }
74 #define DECLARE_WAIT_QUEUE_HEAD(name) \
75 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
77 #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
78 { .flags = word, .bit_nr = bit, }
80 extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *);
82 #define init_waitqueue_head(q) \
84 static struct lock_class_key __key; \
86 __init_waitqueue_head((q), #q, &__key); \
90 # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
91 ({ init_waitqueue_head(&name); name; })
92 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
93 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
95 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
98 static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
102 q->func = default_wake_function;
105 static inline void init_waitqueue_func_entry(wait_queue_t *q,
106 wait_queue_func_t func)
113 static inline int waitqueue_active(wait_queue_head_t *q)
115 return !list_empty(&q->task_list);
118 extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
119 extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait);
120 extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
122 static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
124 list_add(&new->task_list, &head->task_list);
128 * Used for wake-one threads:
130 static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
133 wait->flags |= WQ_FLAG_EXCLUSIVE;
134 __add_wait_queue(q, wait);
137 static inline void __add_wait_queue_tail(wait_queue_head_t *head,
140 list_add_tail(&new->task_list, &head->task_list);
143 static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
146 wait->flags |= WQ_FLAG_EXCLUSIVE;
147 __add_wait_queue_tail(q, wait);
150 static inline void __remove_wait_queue(wait_queue_head_t *head,
153 list_del(&old->task_list);
156 void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
157 void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
158 void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr,
160 void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
161 void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
162 void __wake_up_bit(wait_queue_head_t *, void *, int);
163 int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
164 int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
165 void wake_up_bit(void *, int);
166 int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
167 int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
168 wait_queue_head_t *bit_waitqueue(void *, int);
170 #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
171 #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
172 #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
173 #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
174 #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
176 #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
177 #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
178 #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
179 #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
182 * Wakeup macros to be used to report events to the targets.
184 #define wake_up_poll(x, m) \
185 __wake_up(x, TASK_NORMAL, 1, (void *) (m))
186 #define wake_up_locked_poll(x, m) \
187 __wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
188 #define wake_up_interruptible_poll(x, m) \
189 __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
190 #define wake_up_interruptible_sync_poll(x, m) \
191 __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
193 #define __wait_event(wq, condition) \
195 DEFINE_WAIT(__wait); \
198 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
203 finish_wait(&wq, &__wait); \
207 * wait_event - sleep until a condition gets true
208 * @wq: the waitqueue to wait on
209 * @condition: a C expression for the event to wait for
211 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
212 * @condition evaluates to true. The @condition is checked each time
213 * the waitqueue @wq is woken up.
215 * wake_up() has to be called after changing any variable that could
216 * change the result of the wait condition.
218 #define wait_event(wq, condition) \
222 __wait_event(wq, condition); \
225 #define __wait_event_timeout(wq, condition, ret) \
227 DEFINE_WAIT(__wait); \
230 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
233 ret = schedule_timeout(ret); \
237 finish_wait(&wq, &__wait); \
241 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
242 * @wq: the waitqueue to wait on
243 * @condition: a C expression for the event to wait for
244 * @timeout: timeout, in jiffies
246 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
247 * @condition evaluates to true. The @condition is checked each time
248 * the waitqueue @wq is woken up.
250 * wake_up() has to be called after changing any variable that could
251 * change the result of the wait condition.
253 * The function returns 0 if the @timeout elapsed, and the remaining
254 * jiffies if the condition evaluated to true before the timeout elapsed.
256 #define wait_event_timeout(wq, condition, timeout) \
258 long __ret = timeout; \
260 __wait_event_timeout(wq, condition, __ret); \
264 #define __wait_event_interruptible(wq, condition, ret) \
266 DEFINE_WAIT(__wait); \
269 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
272 if (!signal_pending(current)) { \
276 ret = -ERESTARTSYS; \
279 finish_wait(&wq, &__wait); \
283 * wait_event_interruptible - sleep until a condition gets true
284 * @wq: the waitqueue to wait on
285 * @condition: a C expression for the event to wait for
287 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
288 * @condition evaluates to true or a signal is received.
289 * The @condition is checked each time the waitqueue @wq is woken up.
291 * wake_up() has to be called after changing any variable that could
292 * change the result of the wait condition.
294 * The function will return -ERESTARTSYS if it was interrupted by a
295 * signal and 0 if @condition evaluated to true.
297 #define wait_event_interruptible(wq, condition) \
301 __wait_event_interruptible(wq, condition, __ret); \
305 #define __wait_event_interruptible_timeout(wq, condition, ret) \
307 DEFINE_WAIT(__wait); \
310 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
313 if (!signal_pending(current)) { \
314 ret = schedule_timeout(ret); \
319 ret = -ERESTARTSYS; \
322 finish_wait(&wq, &__wait); \
326 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
327 * @wq: the waitqueue to wait on
328 * @condition: a C expression for the event to wait for
329 * @timeout: timeout, in jiffies
331 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
332 * @condition evaluates to true or a signal is received.
333 * The @condition is checked each time the waitqueue @wq is woken up.
335 * wake_up() has to be called after changing any variable that could
336 * change the result of the wait condition.
338 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
339 * was interrupted by a signal, and the remaining jiffies otherwise
340 * if the condition evaluated to true before the timeout elapsed.
342 #define wait_event_interruptible_timeout(wq, condition, timeout) \
344 long __ret = timeout; \
346 __wait_event_interruptible_timeout(wq, condition, __ret); \
350 #define __wait_event_interruptible_exclusive(wq, condition, ret) \
352 DEFINE_WAIT(__wait); \
355 prepare_to_wait_exclusive(&wq, &__wait, \
356 TASK_INTERRUPTIBLE); \
358 finish_wait(&wq, &__wait); \
361 if (!signal_pending(current)) { \
365 ret = -ERESTARTSYS; \
366 abort_exclusive_wait(&wq, &__wait, \
367 TASK_INTERRUPTIBLE, NULL); \
372 #define wait_event_interruptible_exclusive(wq, condition) \
376 __wait_event_interruptible_exclusive(wq, condition, __ret);\
381 #define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
384 DEFINE_WAIT(__wait); \
386 __wait.flags |= WQ_FLAG_EXCLUSIVE; \
388 if (likely(list_empty(&__wait.task_list))) \
389 __add_wait_queue_tail(&(wq), &__wait); \
390 set_current_state(TASK_INTERRUPTIBLE); \
391 if (signal_pending(current)) { \
392 __ret = -ERESTARTSYS; \
396 spin_unlock_irq(&(wq).lock); \
398 spin_unlock(&(wq).lock); \
401 spin_lock_irq(&(wq).lock); \
403 spin_lock(&(wq).lock); \
404 } while (!(condition)); \
405 __remove_wait_queue(&(wq), &__wait); \
406 __set_current_state(TASK_RUNNING); \
412 * wait_event_interruptible_locked - sleep until a condition gets true
413 * @wq: the waitqueue to wait on
414 * @condition: a C expression for the event to wait for
416 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
417 * @condition evaluates to true or a signal is received.
418 * The @condition is checked each time the waitqueue @wq is woken up.
420 * It must be called with wq.lock being held. This spinlock is
421 * unlocked while sleeping but @condition testing is done while lock
422 * is held and when this macro exits the lock is held.
424 * The lock is locked/unlocked using spin_lock()/spin_unlock()
425 * functions which must match the way they are locked/unlocked outside
428 * wake_up_locked() has to be called after changing any variable that could
429 * change the result of the wait condition.
431 * The function will return -ERESTARTSYS if it was interrupted by a
432 * signal and 0 if @condition evaluated to true.
434 #define wait_event_interruptible_locked(wq, condition) \
436 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))
439 * wait_event_interruptible_locked_irq - sleep until a condition gets true
440 * @wq: the waitqueue to wait on
441 * @condition: a C expression for the event to wait for
443 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
444 * @condition evaluates to true or a signal is received.
445 * The @condition is checked each time the waitqueue @wq is woken up.
447 * It must be called with wq.lock being held. This spinlock is
448 * unlocked while sleeping but @condition testing is done while lock
449 * is held and when this macro exits the lock is held.
451 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
452 * functions which must match the way they are locked/unlocked outside
455 * wake_up_locked() has to be called after changing any variable that could
456 * change the result of the wait condition.
458 * The function will return -ERESTARTSYS if it was interrupted by a
459 * signal and 0 if @condition evaluated to true.
461 #define wait_event_interruptible_locked_irq(wq, condition) \
463 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1))
466 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
467 * @wq: the waitqueue to wait on
468 * @condition: a C expression for the event to wait for
470 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
471 * @condition evaluates to true or a signal is received.
472 * The @condition is checked each time the waitqueue @wq is woken up.
474 * It must be called with wq.lock being held. This spinlock is
475 * unlocked while sleeping but @condition testing is done while lock
476 * is held and when this macro exits the lock is held.
478 * The lock is locked/unlocked using spin_lock()/spin_unlock()
479 * functions which must match the way they are locked/unlocked outside
482 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
483 * set thus when other process waits process on the list if this
484 * process is awaken further processes are not considered.
486 * wake_up_locked() has to be called after changing any variable that could
487 * change the result of the wait condition.
489 * The function will return -ERESTARTSYS if it was interrupted by a
490 * signal and 0 if @condition evaluated to true.
492 #define wait_event_interruptible_exclusive_locked(wq, condition) \
494 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0))
497 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
498 * @wq: the waitqueue to wait on
499 * @condition: a C expression for the event to wait for
501 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
502 * @condition evaluates to true or a signal is received.
503 * The @condition is checked each time the waitqueue @wq is woken up.
505 * It must be called with wq.lock being held. This spinlock is
506 * unlocked while sleeping but @condition testing is done while lock
507 * is held and when this macro exits the lock is held.
509 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
510 * functions which must match the way they are locked/unlocked outside
513 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
514 * set thus when other process waits process on the list if this
515 * process is awaken further processes are not considered.
517 * wake_up_locked() has to be called after changing any variable that could
518 * change the result of the wait condition.
520 * The function will return -ERESTARTSYS if it was interrupted by a
521 * signal and 0 if @condition evaluated to true.
523 #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
525 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
529 #define __wait_event_killable(wq, condition, ret) \
531 DEFINE_WAIT(__wait); \
534 prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
537 if (!fatal_signal_pending(current)) { \
541 ret = -ERESTARTSYS; \
544 finish_wait(&wq, &__wait); \
548 * wait_event_killable - sleep until a condition gets true
549 * @wq: the waitqueue to wait on
550 * @condition: a C expression for the event to wait for
552 * The process is put to sleep (TASK_KILLABLE) until the
553 * @condition evaluates to true or a signal is received.
554 * The @condition is checked each time the waitqueue @wq is woken up.
556 * wake_up() has to be called after changing any variable that could
557 * change the result of the wait condition.
559 * The function will return -ERESTARTSYS if it was interrupted by a
560 * signal and 0 if @condition evaluated to true.
562 #define wait_event_killable(wq, condition) \
566 __wait_event_killable(wq, condition, __ret); \
571 * These are the old interfaces to sleep waiting for an event.
572 * They are racy. DO NOT use them, use the wait_event* interfaces above.
573 * We plan to remove these interfaces.
575 extern void sleep_on(wait_queue_head_t *q);
576 extern long sleep_on_timeout(wait_queue_head_t *q,
577 signed long timeout);
578 extern void interruptible_sleep_on(wait_queue_head_t *q);
579 extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
580 signed long timeout);
583 * Waitqueues which are removed from the waitqueue_head at wakeup time
585 void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
586 void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
587 void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
588 void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
589 unsigned int mode, void *key);
590 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
591 int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
593 #define DEFINE_WAIT_FUNC(name, function) \
594 wait_queue_t name = { \
595 .private = current, \
597 .task_list = LIST_HEAD_INIT((name).task_list), \
600 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
602 #define DEFINE_WAIT_BIT(name, word, bit) \
603 struct wait_bit_queue name = { \
604 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
606 .private = current, \
607 .func = wake_bit_function, \
609 LIST_HEAD_INIT((name).wait.task_list), \
613 #define init_wait(wait) \
615 (wait)->private = current; \
616 (wait)->func = autoremove_wake_function; \
617 INIT_LIST_HEAD(&(wait)->task_list); \
622 * wait_on_bit - wait for a bit to be cleared
623 * @word: the word being waited on, a kernel virtual address
624 * @bit: the bit of the word being waited on
625 * @action: the function used to sleep, which may take special actions
626 * @mode: the task state to sleep in
628 * There is a standard hashed waitqueue table for generic use. This
629 * is the part of the hashtable's accessor API that waits on a bit.
630 * For instance, if one were to have waiters on a bitflag, one would
631 * call wait_on_bit() in threads waiting for the bit to clear.
632 * One uses wait_on_bit() where one is waiting for the bit to clear,
633 * but has no intention of setting it.
635 static inline int wait_on_bit(void *word, int bit,
636 int (*action)(void *), unsigned mode)
638 if (!test_bit(bit, word))
640 return out_of_line_wait_on_bit(word, bit, action, mode);
644 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
645 * @word: the word being waited on, a kernel virtual address
646 * @bit: the bit of the word being waited on
647 * @action: the function used to sleep, which may take special actions
648 * @mode: the task state to sleep in
650 * There is a standard hashed waitqueue table for generic use. This
651 * is the part of the hashtable's accessor API that waits on a bit
652 * when one intends to set it, for instance, trying to lock bitflags.
653 * For instance, if one were to have waiters trying to set bitflag
654 * and waiting for it to clear before setting it, one would call
655 * wait_on_bit() in threads waiting to be able to set the bit.
656 * One uses wait_on_bit_lock() where one is waiting for the bit to
657 * clear with the intention of setting it, and when done, clearing it.
659 static inline int wait_on_bit_lock(void *word, int bit,
660 int (*action)(void *), unsigned mode)
662 if (!test_and_set_bit(bit, word))
664 return out_of_line_wait_on_bit_lock(word, bit, action, mode);
667 #endif /* __KERNEL__ */