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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
Harvey Harrisonb3c97522008-02-13 15:03:15 -0800135void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
136extern void __wake_up_locked(wait_queue_head_t *q, unsigned int mode);
137extern void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
138void __wake_up_bit(wait_queue_head_t *, void *, int);
139int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
140int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
141void wake_up_bit(void *, int);
142int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
143int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
144wait_queue_head_t *bit_waitqueue(void *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
Matthew Wilcoxe64d66c2007-12-06 17:34:36 -0500146#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
147#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
148#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
149#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL)
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
152#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
153#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
Matthew Wilcoxe64d66c2007-12-06 17:34:36 -0500154#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
Peter Zijlstra0ccf8312008-02-04 22:27:20 -0800156#ifdef CONFIG_DEBUG_LOCK_ALLOC
157/*
158 * macro to avoid include hell
159 */
160#define wake_up_nested(x, s) \
161do { \
162 unsigned long flags; \
163 \
164 spin_lock_irqsave_nested(&(x)->lock, flags, (s)); \
165 wake_up_locked(x); \
166 spin_unlock_irqrestore(&(x)->lock, flags); \
167} while (0)
168#else
169#define wake_up_nested(x, s) wake_up(x)
170#endif
171
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172#define __wait_event(wq, condition) \
173do { \
174 DEFINE_WAIT(__wait); \
175 \
176 for (;;) { \
177 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
178 if (condition) \
179 break; \
180 schedule(); \
181 } \
182 finish_wait(&wq, &__wait); \
183} while (0)
184
185/**
186 * wait_event - sleep until a condition gets true
187 * @wq: the waitqueue to wait on
188 * @condition: a C expression for the event to wait for
189 *
190 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
191 * @condition evaluates to true. The @condition is checked each time
192 * the waitqueue @wq is woken up.
193 *
194 * wake_up() has to be called after changing any variable that could
195 * change the result of the wait condition.
196 */
197#define wait_event(wq, condition) \
198do { \
199 if (condition) \
200 break; \
201 __wait_event(wq, condition); \
202} while (0)
203
204#define __wait_event_timeout(wq, condition, ret) \
205do { \
206 DEFINE_WAIT(__wait); \
207 \
208 for (;;) { \
209 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
210 if (condition) \
211 break; \
212 ret = schedule_timeout(ret); \
213 if (!ret) \
214 break; \
215 } \
216 finish_wait(&wq, &__wait); \
217} while (0)
218
219/**
220 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
221 * @wq: the waitqueue to wait on
222 * @condition: a C expression for the event to wait for
223 * @timeout: timeout, in jiffies
224 *
225 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
226 * @condition evaluates to true. The @condition is checked each time
227 * the waitqueue @wq is woken up.
228 *
229 * wake_up() has to be called after changing any variable that could
230 * change the result of the wait condition.
231 *
232 * The function returns 0 if the @timeout elapsed, and the remaining
233 * jiffies if the condition evaluated to true before the timeout elapsed.
234 */
235#define wait_event_timeout(wq, condition, timeout) \
236({ \
237 long __ret = timeout; \
238 if (!(condition)) \
239 __wait_event_timeout(wq, condition, __ret); \
240 __ret; \
241})
242
243#define __wait_event_interruptible(wq, condition, ret) \
244do { \
245 DEFINE_WAIT(__wait); \
246 \
247 for (;;) { \
248 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
249 if (condition) \
250 break; \
251 if (!signal_pending(current)) { \
252 schedule(); \
253 continue; \
254 } \
255 ret = -ERESTARTSYS; \
256 break; \
257 } \
258 finish_wait(&wq, &__wait); \
259} while (0)
260
261/**
262 * wait_event_interruptible - sleep until a condition gets true
263 * @wq: the waitqueue to wait on
264 * @condition: a C expression for the event to wait for
265 *
266 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
267 * @condition evaluates to true or a signal is received.
268 * The @condition is checked each time the waitqueue @wq is woken up.
269 *
270 * wake_up() has to be called after changing any variable that could
271 * change the result of the wait condition.
272 *
273 * The function will return -ERESTARTSYS if it was interrupted by a
274 * signal and 0 if @condition evaluated to true.
275 */
276#define wait_event_interruptible(wq, condition) \
277({ \
278 int __ret = 0; \
279 if (!(condition)) \
280 __wait_event_interruptible(wq, condition, __ret); \
281 __ret; \
282})
283
284#define __wait_event_interruptible_timeout(wq, condition, ret) \
285do { \
286 DEFINE_WAIT(__wait); \
287 \
288 for (;;) { \
289 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
290 if (condition) \
291 break; \
292 if (!signal_pending(current)) { \
293 ret = schedule_timeout(ret); \
294 if (!ret) \
295 break; \
296 continue; \
297 } \
298 ret = -ERESTARTSYS; \
299 break; \
300 } \
301 finish_wait(&wq, &__wait); \
302} while (0)
303
304/**
305 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
306 * @wq: the waitqueue to wait on
307 * @condition: a C expression for the event to wait for
308 * @timeout: timeout, in jiffies
309 *
310 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
311 * @condition evaluates to true or a signal is received.
312 * The @condition is checked each time the waitqueue @wq is woken up.
313 *
314 * wake_up() has to be called after changing any variable that could
315 * change the result of the wait condition.
316 *
317 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
318 * was interrupted by a signal, and the remaining jiffies otherwise
319 * if the condition evaluated to true before the timeout elapsed.
320 */
321#define wait_event_interruptible_timeout(wq, condition, timeout) \
322({ \
323 long __ret = timeout; \
324 if (!(condition)) \
325 __wait_event_interruptible_timeout(wq, condition, __ret); \
326 __ret; \
327})
328
329#define __wait_event_interruptible_exclusive(wq, condition, ret) \
330do { \
331 DEFINE_WAIT(__wait); \
332 \
333 for (;;) { \
334 prepare_to_wait_exclusive(&wq, &__wait, \
335 TASK_INTERRUPTIBLE); \
336 if (condition) \
337 break; \
338 if (!signal_pending(current)) { \
339 schedule(); \
340 continue; \
341 } \
342 ret = -ERESTARTSYS; \
343 break; \
344 } \
345 finish_wait(&wq, &__wait); \
346} while (0)
347
348#define wait_event_interruptible_exclusive(wq, condition) \
349({ \
350 int __ret = 0; \
351 if (!(condition)) \
352 __wait_event_interruptible_exclusive(wq, condition, __ret);\
353 __ret; \
354})
355
Matthew Wilcox1411d5a2007-12-06 12:00:00 -0500356#define __wait_event_killable(wq, condition, ret) \
357do { \
358 DEFINE_WAIT(__wait); \
359 \
360 for (;;) { \
361 prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
362 if (condition) \
363 break; \
364 if (!fatal_signal_pending(current)) { \
365 schedule(); \
366 continue; \
367 } \
368 ret = -ERESTARTSYS; \
369 break; \
370 } \
371 finish_wait(&wq, &__wait); \
372} while (0)
373
374/**
375 * wait_event_killable - sleep until a condition gets true
376 * @wq: the waitqueue to wait on
377 * @condition: a C expression for the event to wait for
378 *
379 * The process is put to sleep (TASK_KILLABLE) until the
380 * @condition evaluates to true or a signal is received.
381 * The @condition is checked each time the waitqueue @wq is woken up.
382 *
383 * wake_up() has to be called after changing any variable that could
384 * change the result of the wait condition.
385 *
386 * The function will return -ERESTARTSYS if it was interrupted by a
387 * signal and 0 if @condition evaluated to true.
388 */
389#define wait_event_killable(wq, condition) \
390({ \
391 int __ret = 0; \
392 if (!(condition)) \
393 __wait_event_killable(wq, condition, __ret); \
394 __ret; \
395})
396
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397/*
398 * Must be called with the spinlock in the wait_queue_head_t held.
399 */
400static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
401 wait_queue_t * wait)
402{
403 wait->flags |= WQ_FLAG_EXCLUSIVE;
404 __add_wait_queue_tail(q, wait);
405}
406
407/*
408 * Must be called with the spinlock in the wait_queue_head_t held.
409 */
410static inline void remove_wait_queue_locked(wait_queue_head_t *q,
411 wait_queue_t * wait)
412{
413 __remove_wait_queue(q, wait);
414}
415
416/*
417 * These are the old interfaces to sleep waiting for an event.
Ingo Molnar0fec1712007-07-09 18:52:01 +0200418 * They are racy. DO NOT use them, use the wait_event* interfaces above.
419 * We plan to remove these interfaces.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 */
Ingo Molnar0fec1712007-07-09 18:52:01 +0200421extern void sleep_on(wait_queue_head_t *q);
422extern long sleep_on_timeout(wait_queue_head_t *q,
423 signed long timeout);
424extern void interruptible_sleep_on(wait_queue_head_t *q);
425extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
426 signed long timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
428/*
429 * Waitqueues which are removed from the waitqueue_head at wakeup time
430 */
Harvey Harrisonb3c97522008-02-13 15:03:15 -0800431void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
432void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
433void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
435int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
436
437#define DEFINE_WAIT(name) \
438 wait_queue_t name = { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700439 .private = current, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 .func = autoremove_wake_function, \
blaisorblade@yahoo.it7e43c842005-05-25 01:31:42 +0200441 .task_list = LIST_HEAD_INIT((name).task_list), \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 }
443
444#define DEFINE_WAIT_BIT(name, word, bit) \
445 struct wait_bit_queue name = { \
446 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
447 .wait = { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700448 .private = current, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 .func = wake_bit_function, \
450 .task_list = \
451 LIST_HEAD_INIT((name).wait.task_list), \
452 }, \
453 }
454
455#define init_wait(wait) \
456 do { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700457 (wait)->private = current; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 (wait)->func = autoremove_wake_function; \
459 INIT_LIST_HEAD(&(wait)->task_list); \
460 } while (0)
461
462/**
463 * wait_on_bit - wait for a bit to be cleared
464 * @word: the word being waited on, a kernel virtual address
465 * @bit: the bit of the word being waited on
466 * @action: the function used to sleep, which may take special actions
467 * @mode: the task state to sleep in
468 *
469 * There is a standard hashed waitqueue table for generic use. This
470 * is the part of the hashtable's accessor API that waits on a bit.
471 * For instance, if one were to have waiters on a bitflag, one would
472 * call wait_on_bit() in threads waiting for the bit to clear.
473 * One uses wait_on_bit() where one is waiting for the bit to clear,
474 * but has no intention of setting it.
475 */
476static inline int wait_on_bit(void *word, int bit,
477 int (*action)(void *), unsigned mode)
478{
479 if (!test_bit(bit, word))
480 return 0;
481 return out_of_line_wait_on_bit(word, bit, action, mode);
482}
483
484/**
485 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
486 * @word: the word being waited on, a kernel virtual address
487 * @bit: the bit of the word being waited on
488 * @action: the function used to sleep, which may take special actions
489 * @mode: the task state to sleep in
490 *
491 * There is a standard hashed waitqueue table for generic use. This
492 * is the part of the hashtable's accessor API that waits on a bit
493 * when one intends to set it, for instance, trying to lock bitflags.
494 * For instance, if one were to have waiters trying to set bitflag
495 * and waiting for it to clear before setting it, one would call
496 * wait_on_bit() in threads waiting to be able to set the bit.
497 * One uses wait_on_bit_lock() where one is waiting for the bit to
498 * clear with the intention of setting it, and when done, clearing it.
499 */
500static inline int wait_on_bit_lock(void *word, int bit,
501 int (*action)(void *), unsigned mode)
502{
503 if (!test_and_set_bit(bit, word))
504 return 0;
505 return out_of_line_wait_on_bit_lock(word, bit, action, mode);
506}
507
508#endif /* __KERNEL__ */
509
510#endif