blob: a210ede73b568d25bc672b44c8bd17986d326b7e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_WAIT_H
2#define _LINUX_WAIT_H
3
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. */
10
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 */
14
15/* First argument to waitid: */
16#define P_ALL 0
17#define P_PID 1
18#define P_PGID 2
19
20#ifdef __KERNEL__
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/list.h>
23#include <linux/stddef.h>
24#include <linux/spinlock.h>
25#include <asm/system.h>
26#include <asm/current.h>
27
28typedef struct __wait_queue wait_queue_t;
29typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key);
30int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
31
32struct __wait_queue {
33 unsigned int flags;
34#define WQ_FLAG_EXCLUSIVE 0x01
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -070035 void *private;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 wait_queue_func_t func;
37 struct list_head task_list;
38};
39
40struct wait_bit_key {
41 void *flags;
42 int bit_nr;
43};
44
45struct wait_bit_queue {
46 struct wait_bit_key key;
47 wait_queue_t wait;
48};
49
50struct __wait_queue_head {
51 spinlock_t lock;
52 struct list_head task_list;
53};
54typedef struct __wait_queue_head wait_queue_head_t;
55
Tim Schmielau8c65b4a2005-11-07 00:59:43 -080056struct task_struct;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58/*
59 * Macros for declaration and initialisaton of the datatypes
60 */
61
62#define __WAITQUEUE_INITIALIZER(name, tsk) { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -070063 .private = tsk, \
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 .func = default_wake_function, \
65 .task_list = { NULL, NULL } }
66
67#define DECLARE_WAITQUEUE(name, tsk) \
68 wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
69
70#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
Ingo Molnare4d91912006-07-03 00:24:34 -070071 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 .task_list = { &(name).task_list, &(name).task_list } }
73
74#define DECLARE_WAIT_QUEUE_HEAD(name) \
75 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
76
77#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
78 { .flags = word, .bit_nr = bit, }
79
Ingo Molnar21d71f52006-07-10 04:45:32 -070080extern void init_waitqueue_head(wait_queue_head_t *q);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Peter Zijlstra7259f0d2006-10-29 22:46:36 -080082#ifdef CONFIG_LOCKDEP
83# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
84 ({ init_waitqueue_head(&name); name; })
85# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
86 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
87#else
88# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
89#endif
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
92{
93 q->flags = 0;
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -070094 q->private = p;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 q->func = default_wake_function;
96}
97
98static inline void init_waitqueue_func_entry(wait_queue_t *q,
99 wait_queue_func_t func)
100{
101 q->flags = 0;
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700102 q->private = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 q->func = func;
104}
105
106static inline int waitqueue_active(wait_queue_head_t *q)
107{
108 return !list_empty(&q->task_list);
109}
110
Harvey Harrisonb3c97522008-02-13 15:03:15 -0800111extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
112extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait);
113extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
116{
117 list_add(&new->task_list, &head->task_list);
118}
119
120/*
121 * Used for wake-one threads:
122 */
123static inline void __add_wait_queue_tail(wait_queue_head_t *head,
124 wait_queue_t *new)
125{
126 list_add_tail(&new->task_list, &head->task_list);
127}
128
129static inline void __remove_wait_queue(wait_queue_head_t *head,
130 wait_queue_t *old)
131{
132 list_del(&old->task_list);
133}
134
Johannes Weiner777c6c52009-02-04 15:12:14 -0800135void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
136 int nr_exclusive, int sync, void *key);
Harvey Harrisonb3c97522008-02-13 15:03:15 -0800137void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
138extern void __wake_up_locked(wait_queue_head_t *q, unsigned int mode);
139extern void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
140void __wake_up_bit(wait_queue_head_t *, void *, int);
141int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
142int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
143void wake_up_bit(void *, int);
144int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
145int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
146wait_queue_head_t *bit_waitqueue(void *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Matthew Wilcoxe64d66c2007-12-06 17:34:36 -0500148#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
149#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
150#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
151#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL)
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
154#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
155#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
Matthew Wilcoxe64d66c2007-12-06 17:34:36 -0500156#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Peter Zijlstra0ccf8312008-02-04 22:27:20 -0800158#ifdef CONFIG_DEBUG_LOCK_ALLOC
159/*
160 * macro to avoid include hell
161 */
162#define wake_up_nested(x, s) \
163do { \
164 unsigned long flags; \
165 \
166 spin_lock_irqsave_nested(&(x)->lock, flags, (s)); \
167 wake_up_locked(x); \
168 spin_unlock_irqrestore(&(x)->lock, flags); \
169} while (0)
170#else
171#define wake_up_nested(x, s) wake_up(x)
172#endif
173
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174#define __wait_event(wq, condition) \
175do { \
176 DEFINE_WAIT(__wait); \
177 \
178 for (;;) { \
179 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
180 if (condition) \
181 break; \
182 schedule(); \
183 } \
184 finish_wait(&wq, &__wait); \
185} while (0)
186
187/**
188 * wait_event - sleep until a condition gets true
189 * @wq: the waitqueue to wait on
190 * @condition: a C expression for the event to wait for
191 *
192 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
193 * @condition evaluates to true. The @condition is checked each time
194 * the waitqueue @wq is woken up.
195 *
196 * wake_up() has to be called after changing any variable that could
197 * change the result of the wait condition.
198 */
199#define wait_event(wq, condition) \
200do { \
201 if (condition) \
202 break; \
203 __wait_event(wq, condition); \
204} while (0)
205
206#define __wait_event_timeout(wq, condition, ret) \
207do { \
208 DEFINE_WAIT(__wait); \
209 \
210 for (;;) { \
211 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
212 if (condition) \
213 break; \
214 ret = schedule_timeout(ret); \
215 if (!ret) \
216 break; \
217 } \
218 finish_wait(&wq, &__wait); \
219} while (0)
220
221/**
222 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
223 * @wq: the waitqueue to wait on
224 * @condition: a C expression for the event to wait for
225 * @timeout: timeout, in jiffies
226 *
227 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
228 * @condition evaluates to true. The @condition is checked each time
229 * the waitqueue @wq is woken up.
230 *
231 * wake_up() has to be called after changing any variable that could
232 * change the result of the wait condition.
233 *
234 * The function returns 0 if the @timeout elapsed, and the remaining
235 * jiffies if the condition evaluated to true before the timeout elapsed.
236 */
237#define wait_event_timeout(wq, condition, timeout) \
238({ \
239 long __ret = timeout; \
240 if (!(condition)) \
241 __wait_event_timeout(wq, condition, __ret); \
242 __ret; \
243})
244
245#define __wait_event_interruptible(wq, condition, ret) \
246do { \
247 DEFINE_WAIT(__wait); \
248 \
249 for (;;) { \
250 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
251 if (condition) \
252 break; \
253 if (!signal_pending(current)) { \
254 schedule(); \
255 continue; \
256 } \
257 ret = -ERESTARTSYS; \
258 break; \
259 } \
260 finish_wait(&wq, &__wait); \
261} while (0)
262
263/**
264 * wait_event_interruptible - sleep until a condition gets true
265 * @wq: the waitqueue to wait on
266 * @condition: a C expression for the event to wait for
267 *
268 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
269 * @condition evaluates to true or a signal is received.
270 * The @condition is checked each time the waitqueue @wq is woken up.
271 *
272 * wake_up() has to be called after changing any variable that could
273 * change the result of the wait condition.
274 *
275 * The function will return -ERESTARTSYS if it was interrupted by a
276 * signal and 0 if @condition evaluated to true.
277 */
278#define wait_event_interruptible(wq, condition) \
279({ \
280 int __ret = 0; \
281 if (!(condition)) \
282 __wait_event_interruptible(wq, condition, __ret); \
283 __ret; \
284})
285
286#define __wait_event_interruptible_timeout(wq, condition, ret) \
287do { \
288 DEFINE_WAIT(__wait); \
289 \
290 for (;;) { \
291 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
292 if (condition) \
293 break; \
294 if (!signal_pending(current)) { \
295 ret = schedule_timeout(ret); \
296 if (!ret) \
297 break; \
298 continue; \
299 } \
300 ret = -ERESTARTSYS; \
301 break; \
302 } \
303 finish_wait(&wq, &__wait); \
304} while (0)
305
306/**
307 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
308 * @wq: the waitqueue to wait on
309 * @condition: a C expression for the event to wait for
310 * @timeout: timeout, in jiffies
311 *
312 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
313 * @condition evaluates to true or a signal is received.
314 * The @condition is checked each time the waitqueue @wq is woken up.
315 *
316 * wake_up() has to be called after changing any variable that could
317 * change the result of the wait condition.
318 *
319 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
320 * was interrupted by a signal, and the remaining jiffies otherwise
321 * if the condition evaluated to true before the timeout elapsed.
322 */
323#define wait_event_interruptible_timeout(wq, condition, timeout) \
324({ \
325 long __ret = timeout; \
326 if (!(condition)) \
327 __wait_event_interruptible_timeout(wq, condition, __ret); \
328 __ret; \
329})
330
331#define __wait_event_interruptible_exclusive(wq, condition, ret) \
332do { \
333 DEFINE_WAIT(__wait); \
334 \
335 for (;;) { \
336 prepare_to_wait_exclusive(&wq, &__wait, \
337 TASK_INTERRUPTIBLE); \
Johannes Weiner777c6c52009-02-04 15:12:14 -0800338 if (condition) { \
339 finish_wait(&wq, &__wait); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 break; \
Johannes Weiner777c6c52009-02-04 15:12:14 -0800341 } \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 if (!signal_pending(current)) { \
343 schedule(); \
344 continue; \
345 } \
346 ret = -ERESTARTSYS; \
Johannes Weiner777c6c52009-02-04 15:12:14 -0800347 abort_exclusive_wait(&wq, &__wait, \
348 TASK_INTERRUPTIBLE, NULL); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 break; \
350 } \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351} while (0)
352
353#define wait_event_interruptible_exclusive(wq, condition) \
354({ \
355 int __ret = 0; \
356 if (!(condition)) \
357 __wait_event_interruptible_exclusive(wq, condition, __ret);\
358 __ret; \
359})
360
Matthew Wilcox1411d5a2007-12-06 12:00:00 -0500361#define __wait_event_killable(wq, condition, ret) \
362do { \
363 DEFINE_WAIT(__wait); \
364 \
365 for (;;) { \
366 prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
367 if (condition) \
368 break; \
369 if (!fatal_signal_pending(current)) { \
370 schedule(); \
371 continue; \
372 } \
373 ret = -ERESTARTSYS; \
374 break; \
375 } \
376 finish_wait(&wq, &__wait); \
377} while (0)
378
379/**
380 * wait_event_killable - sleep until a condition gets true
381 * @wq: the waitqueue to wait on
382 * @condition: a C expression for the event to wait for
383 *
384 * The process is put to sleep (TASK_KILLABLE) until the
385 * @condition evaluates to true or a signal is received.
386 * The @condition is checked each time the waitqueue @wq is woken up.
387 *
388 * wake_up() has to be called after changing any variable that could
389 * change the result of the wait condition.
390 *
391 * The function will return -ERESTARTSYS if it was interrupted by a
392 * signal and 0 if @condition evaluated to true.
393 */
394#define wait_event_killable(wq, condition) \
395({ \
396 int __ret = 0; \
397 if (!(condition)) \
398 __wait_event_killable(wq, condition, __ret); \
399 __ret; \
400})
401
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402/*
403 * Must be called with the spinlock in the wait_queue_head_t held.
404 */
405static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
406 wait_queue_t * wait)
407{
408 wait->flags |= WQ_FLAG_EXCLUSIVE;
409 __add_wait_queue_tail(q, wait);
410}
411
412/*
413 * Must be called with the spinlock in the wait_queue_head_t held.
414 */
415static inline void remove_wait_queue_locked(wait_queue_head_t *q,
416 wait_queue_t * wait)
417{
418 __remove_wait_queue(q, wait);
419}
420
421/*
422 * These are the old interfaces to sleep waiting for an event.
Ingo Molnar0fec1712007-07-09 18:52:01 +0200423 * They are racy. DO NOT use them, use the wait_event* interfaces above.
424 * We plan to remove these interfaces.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 */
Ingo Molnar0fec1712007-07-09 18:52:01 +0200426extern void sleep_on(wait_queue_head_t *q);
427extern long sleep_on_timeout(wait_queue_head_t *q,
428 signed long timeout);
429extern void interruptible_sleep_on(wait_queue_head_t *q);
430extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
431 signed long timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
433/*
434 * Waitqueues which are removed from the waitqueue_head at wakeup time
435 */
Harvey Harrisonb3c97522008-02-13 15:03:15 -0800436void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
437void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
438void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
Johannes Weiner777c6c52009-02-04 15:12:14 -0800439void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
440 unsigned int mode, void *key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
442int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
443
444#define DEFINE_WAIT(name) \
445 wait_queue_t name = { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700446 .private = current, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 .func = autoremove_wake_function, \
blaisorblade@yahoo.it7e43c842005-05-25 01:31:42 +0200448 .task_list = LIST_HEAD_INIT((name).task_list), \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 }
450
451#define DEFINE_WAIT_BIT(name, word, bit) \
452 struct wait_bit_queue name = { \
453 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
454 .wait = { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700455 .private = current, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 .func = wake_bit_function, \
457 .task_list = \
458 LIST_HEAD_INIT((name).wait.task_list), \
459 }, \
460 }
461
462#define init_wait(wait) \
463 do { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700464 (wait)->private = current; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 (wait)->func = autoremove_wake_function; \
466 INIT_LIST_HEAD(&(wait)->task_list); \
467 } while (0)
468
469/**
470 * wait_on_bit - wait for a bit to be cleared
471 * @word: the word being waited on, a kernel virtual address
472 * @bit: the bit of the word being waited on
473 * @action: the function used to sleep, which may take special actions
474 * @mode: the task state to sleep in
475 *
476 * There is a standard hashed waitqueue table for generic use. This
477 * is the part of the hashtable's accessor API that waits on a bit.
478 * For instance, if one were to have waiters on a bitflag, one would
479 * call wait_on_bit() in threads waiting for the bit to clear.
480 * One uses wait_on_bit() where one is waiting for the bit to clear,
481 * but has no intention of setting it.
482 */
483static inline int wait_on_bit(void *word, int bit,
484 int (*action)(void *), unsigned mode)
485{
486 if (!test_bit(bit, word))
487 return 0;
488 return out_of_line_wait_on_bit(word, bit, action, mode);
489}
490
491/**
492 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
493 * @word: the word being waited on, a kernel virtual address
494 * @bit: the bit of the word being waited on
495 * @action: the function used to sleep, which may take special actions
496 * @mode: the task state to sleep in
497 *
498 * There is a standard hashed waitqueue table for generic use. This
499 * is the part of the hashtable's accessor API that waits on a bit
500 * when one intends to set it, for instance, trying to lock bitflags.
501 * For instance, if one were to have waiters trying to set bitflag
502 * and waiting for it to clear before setting it, one would call
503 * wait_on_bit() in threads waiting to be able to set the bit.
504 * One uses wait_on_bit_lock() where one is waiting for the bit to
505 * clear with the intention of setting it, and when done, clearing it.
506 */
507static inline int wait_on_bit_lock(void *word, int bit,
508 int (*action)(void *), unsigned mode)
509{
510 if (!test_and_set_bit(bit, word))
511 return 0;
512 return out_of_line_wait_on_bit_lock(word, bit, action, mode);
513}
514
515#endif /* __KERNEL__ */
516
517#endif