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1da177e4 LT |
1 | #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 | ||
1da177e4 LT |
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> | |
27 | ||
28 | typedef struct __wait_queue wait_queue_t; | |
29 | typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
30 | int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
31 | ||
32 | struct __wait_queue { | |
33 | unsigned int flags; | |
34 | #define WQ_FLAG_EXCLUSIVE 0x01 | |
c43dc2fd | 35 | void *private; |
1da177e4 LT |
36 | wait_queue_func_t func; |
37 | struct list_head task_list; | |
38 | }; | |
39 | ||
40 | struct wait_bit_key { | |
41 | void *flags; | |
42 | int bit_nr; | |
43 | }; | |
44 | ||
45 | struct wait_bit_queue { | |
46 | struct wait_bit_key key; | |
47 | wait_queue_t wait; | |
48 | }; | |
49 | ||
50 | struct __wait_queue_head { | |
51 | spinlock_t lock; | |
52 | struct list_head task_list; | |
53 | }; | |
54 | typedef struct __wait_queue_head wait_queue_head_t; | |
55 | ||
8c65b4a6 | 56 | struct task_struct; |
1da177e4 LT |
57 | |
58 | /* | |
59 | * Macros for declaration and initialisaton of the datatypes | |
60 | */ | |
61 | ||
62 | #define __WAITQUEUE_INITIALIZER(name, tsk) { \ | |
c43dc2fd | 63 | .private = tsk, \ |
1da177e4 LT |
64 | .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) { \ | |
e4d91918 | 71 | .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ |
1da177e4 LT |
72 | .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 | ||
21d71f51 | 80 | extern void init_waitqueue_head(wait_queue_head_t *q); |
1da177e4 | 81 | |
7259f0d0 PZ |
82 | #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 | ||
1da177e4 LT |
91 | static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) |
92 | { | |
93 | q->flags = 0; | |
c43dc2fd | 94 | q->private = p; |
1da177e4 LT |
95 | q->func = default_wake_function; |
96 | } | |
97 | ||
98 | static inline void init_waitqueue_func_entry(wait_queue_t *q, | |
99 | wait_queue_func_t func) | |
100 | { | |
101 | q->flags = 0; | |
c43dc2fd | 102 | q->private = NULL; |
1da177e4 LT |
103 | q->func = func; |
104 | } | |
105 | ||
106 | static inline int waitqueue_active(wait_queue_head_t *q) | |
107 | { | |
108 | return !list_empty(&q->task_list); | |
109 | } | |
110 | ||
111 | /* | |
112 | * Used to distinguish between sync and async io wait context: | |
113 | * sync i/o typically specifies a NULL wait queue entry or a wait | |
114 | * queue entry bound to a task (current task) to wake up. | |
115 | * aio specifies a wait queue entry with an async notification | |
116 | * callback routine, not associated with any task. | |
117 | */ | |
c43dc2fd | 118 | #define is_sync_wait(wait) (!(wait) || ((wait)->private)) |
1da177e4 | 119 | |
b3c97528 HH |
120 | extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); |
121 | extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait); | |
122 | extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); | |
1da177e4 LT |
123 | |
124 | static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) | |
125 | { | |
126 | list_add(&new->task_list, &head->task_list); | |
127 | } | |
128 | ||
129 | /* | |
130 | * Used for wake-one threads: | |
131 | */ | |
132 | static inline void __add_wait_queue_tail(wait_queue_head_t *head, | |
133 | wait_queue_t *new) | |
134 | { | |
135 | list_add_tail(&new->task_list, &head->task_list); | |
136 | } | |
137 | ||
138 | static inline void __remove_wait_queue(wait_queue_head_t *head, | |
139 | wait_queue_t *old) | |
140 | { | |
141 | list_del(&old->task_list); | |
142 | } | |
143 | ||
b3c97528 HH |
144 | void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key); |
145 | extern void __wake_up_locked(wait_queue_head_t *q, unsigned int mode); | |
146 | extern void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr); | |
147 | void __wake_up_bit(wait_queue_head_t *, void *, int); | |
148 | int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned); | |
149 | int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned); | |
150 | void wake_up_bit(void *, int); | |
151 | int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned); | |
152 | int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned); | |
153 | wait_queue_head_t *bit_waitqueue(void *, int); | |
1da177e4 | 154 | |
e64d66c8 MW |
155 | #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) |
156 | #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) | |
157 | #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) | |
158 | #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL) | |
159 | ||
1da177e4 LT |
160 | #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) |
161 | #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) | |
162 | #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) | |
e64d66c8 | 163 | #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1) |
1da177e4 | 164 | |
0ccf831c PZ |
165 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
166 | /* | |
167 | * macro to avoid include hell | |
168 | */ | |
169 | #define wake_up_nested(x, s) \ | |
170 | do { \ | |
171 | unsigned long flags; \ | |
172 | \ | |
173 | spin_lock_irqsave_nested(&(x)->lock, flags, (s)); \ | |
174 | wake_up_locked(x); \ | |
175 | spin_unlock_irqrestore(&(x)->lock, flags); \ | |
176 | } while (0) | |
177 | #else | |
178 | #define wake_up_nested(x, s) wake_up(x) | |
179 | #endif | |
180 | ||
1da177e4 LT |
181 | #define __wait_event(wq, condition) \ |
182 | do { \ | |
183 | DEFINE_WAIT(__wait); \ | |
184 | \ | |
185 | for (;;) { \ | |
186 | prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ | |
187 | if (condition) \ | |
188 | break; \ | |
189 | schedule(); \ | |
190 | } \ | |
191 | finish_wait(&wq, &__wait); \ | |
192 | } while (0) | |
193 | ||
194 | /** | |
195 | * wait_event - sleep until a condition gets true | |
196 | * @wq: the waitqueue to wait on | |
197 | * @condition: a C expression for the event to wait for | |
198 | * | |
199 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
200 | * @condition evaluates to true. The @condition is checked each time | |
201 | * the waitqueue @wq is woken up. | |
202 | * | |
203 | * wake_up() has to be called after changing any variable that could | |
204 | * change the result of the wait condition. | |
205 | */ | |
206 | #define wait_event(wq, condition) \ | |
207 | do { \ | |
208 | if (condition) \ | |
209 | break; \ | |
210 | __wait_event(wq, condition); \ | |
211 | } while (0) | |
212 | ||
213 | #define __wait_event_timeout(wq, condition, ret) \ | |
214 | do { \ | |
215 | DEFINE_WAIT(__wait); \ | |
216 | \ | |
217 | for (;;) { \ | |
218 | prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ | |
219 | if (condition) \ | |
220 | break; \ | |
221 | ret = schedule_timeout(ret); \ | |
222 | if (!ret) \ | |
223 | break; \ | |
224 | } \ | |
225 | finish_wait(&wq, &__wait); \ | |
226 | } while (0) | |
227 | ||
228 | /** | |
229 | * wait_event_timeout - sleep until a condition gets true or a timeout elapses | |
230 | * @wq: the waitqueue to wait on | |
231 | * @condition: a C expression for the event to wait for | |
232 | * @timeout: timeout, in jiffies | |
233 | * | |
234 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
235 | * @condition evaluates to true. The @condition is checked each time | |
236 | * the waitqueue @wq is woken up. | |
237 | * | |
238 | * wake_up() has to be called after changing any variable that could | |
239 | * change the result of the wait condition. | |
240 | * | |
241 | * The function returns 0 if the @timeout elapsed, and the remaining | |
242 | * jiffies if the condition evaluated to true before the timeout elapsed. | |
243 | */ | |
244 | #define wait_event_timeout(wq, condition, timeout) \ | |
245 | ({ \ | |
246 | long __ret = timeout; \ | |
247 | if (!(condition)) \ | |
248 | __wait_event_timeout(wq, condition, __ret); \ | |
249 | __ret; \ | |
250 | }) | |
251 | ||
252 | #define __wait_event_interruptible(wq, condition, ret) \ | |
253 | do { \ | |
254 | DEFINE_WAIT(__wait); \ | |
255 | \ | |
256 | for (;;) { \ | |
257 | prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ | |
258 | if (condition) \ | |
259 | break; \ | |
260 | if (!signal_pending(current)) { \ | |
261 | schedule(); \ | |
262 | continue; \ | |
263 | } \ | |
264 | ret = -ERESTARTSYS; \ | |
265 | break; \ | |
266 | } \ | |
267 | finish_wait(&wq, &__wait); \ | |
268 | } while (0) | |
269 | ||
270 | /** | |
271 | * wait_event_interruptible - sleep until a condition gets true | |
272 | * @wq: the waitqueue to wait on | |
273 | * @condition: a C expression for the event to wait for | |
274 | * | |
275 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
276 | * @condition evaluates to true or a signal is received. | |
277 | * The @condition is checked each time the waitqueue @wq is woken up. | |
278 | * | |
279 | * wake_up() has to be called after changing any variable that could | |
280 | * change the result of the wait condition. | |
281 | * | |
282 | * The function will return -ERESTARTSYS if it was interrupted by a | |
283 | * signal and 0 if @condition evaluated to true. | |
284 | */ | |
285 | #define wait_event_interruptible(wq, condition) \ | |
286 | ({ \ | |
287 | int __ret = 0; \ | |
288 | if (!(condition)) \ | |
289 | __wait_event_interruptible(wq, condition, __ret); \ | |
290 | __ret; \ | |
291 | }) | |
292 | ||
293 | #define __wait_event_interruptible_timeout(wq, condition, ret) \ | |
294 | do { \ | |
295 | DEFINE_WAIT(__wait); \ | |
296 | \ | |
297 | for (;;) { \ | |
298 | prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ | |
299 | if (condition) \ | |
300 | break; \ | |
301 | if (!signal_pending(current)) { \ | |
302 | ret = schedule_timeout(ret); \ | |
303 | if (!ret) \ | |
304 | break; \ | |
305 | continue; \ | |
306 | } \ | |
307 | ret = -ERESTARTSYS; \ | |
308 | break; \ | |
309 | } \ | |
310 | finish_wait(&wq, &__wait); \ | |
311 | } while (0) | |
312 | ||
313 | /** | |
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 | |
318 | * | |
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. | |
322 | * | |
323 | * wake_up() has to be called after changing any variable that could | |
324 | * change the result of the wait condition. | |
325 | * | |
326 | * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it | |
327 | * was interrupted by a signal, and the remaining jiffies otherwise | |
328 | * if the condition evaluated to true before the timeout elapsed. | |
329 | */ | |
330 | #define wait_event_interruptible_timeout(wq, condition, timeout) \ | |
331 | ({ \ | |
332 | long __ret = timeout; \ | |
333 | if (!(condition)) \ | |
334 | __wait_event_interruptible_timeout(wq, condition, __ret); \ | |
335 | __ret; \ | |
336 | }) | |
337 | ||
338 | #define __wait_event_interruptible_exclusive(wq, condition, ret) \ | |
339 | do { \ | |
340 | DEFINE_WAIT(__wait); \ | |
341 | \ | |
342 | for (;;) { \ | |
343 | prepare_to_wait_exclusive(&wq, &__wait, \ | |
344 | TASK_INTERRUPTIBLE); \ | |
345 | if (condition) \ | |
346 | break; \ | |
347 | if (!signal_pending(current)) { \ | |
348 | schedule(); \ | |
349 | continue; \ | |
350 | } \ | |
351 | ret = -ERESTARTSYS; \ | |
352 | break; \ | |
353 | } \ | |
354 | finish_wait(&wq, &__wait); \ | |
355 | } while (0) | |
356 | ||
357 | #define wait_event_interruptible_exclusive(wq, condition) \ | |
358 | ({ \ | |
359 | int __ret = 0; \ | |
360 | if (!(condition)) \ | |
361 | __wait_event_interruptible_exclusive(wq, condition, __ret);\ | |
362 | __ret; \ | |
363 | }) | |
364 | ||
1411d5a7 MW |
365 | #define __wait_event_killable(wq, condition, ret) \ |
366 | do { \ | |
367 | DEFINE_WAIT(__wait); \ | |
368 | \ | |
369 | for (;;) { \ | |
370 | prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \ | |
371 | if (condition) \ | |
372 | break; \ | |
373 | if (!fatal_signal_pending(current)) { \ | |
374 | schedule(); \ | |
375 | continue; \ | |
376 | } \ | |
377 | ret = -ERESTARTSYS; \ | |
378 | break; \ | |
379 | } \ | |
380 | finish_wait(&wq, &__wait); \ | |
381 | } while (0) | |
382 | ||
383 | /** | |
384 | * wait_event_killable - sleep until a condition gets true | |
385 | * @wq: the waitqueue to wait on | |
386 | * @condition: a C expression for the event to wait for | |
387 | * | |
388 | * The process is put to sleep (TASK_KILLABLE) until the | |
389 | * @condition evaluates to true or a signal is received. | |
390 | * The @condition is checked each time the waitqueue @wq is woken up. | |
391 | * | |
392 | * wake_up() has to be called after changing any variable that could | |
393 | * change the result of the wait condition. | |
394 | * | |
395 | * The function will return -ERESTARTSYS if it was interrupted by a | |
396 | * signal and 0 if @condition evaluated to true. | |
397 | */ | |
398 | #define wait_event_killable(wq, condition) \ | |
399 | ({ \ | |
400 | int __ret = 0; \ | |
401 | if (!(condition)) \ | |
402 | __wait_event_killable(wq, condition, __ret); \ | |
403 | __ret; \ | |
404 | }) | |
405 | ||
1da177e4 LT |
406 | /* |
407 | * Must be called with the spinlock in the wait_queue_head_t held. | |
408 | */ | |
409 | static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q, | |
410 | wait_queue_t * wait) | |
411 | { | |
412 | wait->flags |= WQ_FLAG_EXCLUSIVE; | |
413 | __add_wait_queue_tail(q, wait); | |
414 | } | |
415 | ||
416 | /* | |
417 | * Must be called with the spinlock in the wait_queue_head_t held. | |
418 | */ | |
419 | static inline void remove_wait_queue_locked(wait_queue_head_t *q, | |
420 | wait_queue_t * wait) | |
421 | { | |
422 | __remove_wait_queue(q, wait); | |
423 | } | |
424 | ||
425 | /* | |
426 | * These are the old interfaces to sleep waiting for an event. | |
0fec171c IM |
427 | * They are racy. DO NOT use them, use the wait_event* interfaces above. |
428 | * We plan to remove these interfaces. | |
1da177e4 | 429 | */ |
0fec171c IM |
430 | extern void sleep_on(wait_queue_head_t *q); |
431 | extern long sleep_on_timeout(wait_queue_head_t *q, | |
432 | signed long timeout); | |
433 | extern void interruptible_sleep_on(wait_queue_head_t *q); | |
434 | extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, | |
435 | signed long timeout); | |
1da177e4 LT |
436 | |
437 | /* | |
438 | * Waitqueues which are removed from the waitqueue_head at wakeup time | |
439 | */ | |
b3c97528 HH |
440 | void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); |
441 | void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); | |
442 | void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); | |
1da177e4 LT |
443 | int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); |
444 | int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
445 | ||
446 | #define DEFINE_WAIT(name) \ | |
447 | wait_queue_t name = { \ | |
c43dc2fd | 448 | .private = current, \ |
1da177e4 | 449 | .func = autoremove_wake_function, \ |
7e43c84e | 450 | .task_list = LIST_HEAD_INIT((name).task_list), \ |
1da177e4 LT |
451 | } |
452 | ||
453 | #define DEFINE_WAIT_BIT(name, word, bit) \ | |
454 | struct wait_bit_queue name = { \ | |
455 | .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ | |
456 | .wait = { \ | |
c43dc2fd | 457 | .private = current, \ |
1da177e4 LT |
458 | .func = wake_bit_function, \ |
459 | .task_list = \ | |
460 | LIST_HEAD_INIT((name).wait.task_list), \ | |
461 | }, \ | |
462 | } | |
463 | ||
464 | #define init_wait(wait) \ | |
465 | do { \ | |
c43dc2fd | 466 | (wait)->private = current; \ |
1da177e4 LT |
467 | (wait)->func = autoremove_wake_function; \ |
468 | INIT_LIST_HEAD(&(wait)->task_list); \ | |
469 | } while (0) | |
470 | ||
471 | /** | |
472 | * wait_on_bit - wait for a bit to be cleared | |
473 | * @word: the word being waited on, a kernel virtual address | |
474 | * @bit: the bit of the word being waited on | |
475 | * @action: the function used to sleep, which may take special actions | |
476 | * @mode: the task state to sleep in | |
477 | * | |
478 | * There is a standard hashed waitqueue table for generic use. This | |
479 | * is the part of the hashtable's accessor API that waits on a bit. | |
480 | * For instance, if one were to have waiters on a bitflag, one would | |
481 | * call wait_on_bit() in threads waiting for the bit to clear. | |
482 | * One uses wait_on_bit() where one is waiting for the bit to clear, | |
483 | * but has no intention of setting it. | |
484 | */ | |
485 | static inline int wait_on_bit(void *word, int bit, | |
486 | int (*action)(void *), unsigned mode) | |
487 | { | |
488 | if (!test_bit(bit, word)) | |
489 | return 0; | |
490 | return out_of_line_wait_on_bit(word, bit, action, mode); | |
491 | } | |
492 | ||
493 | /** | |
494 | * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it | |
495 | * @word: the word being waited on, a kernel virtual address | |
496 | * @bit: the bit of the word being waited on | |
497 | * @action: the function used to sleep, which may take special actions | |
498 | * @mode: the task state to sleep in | |
499 | * | |
500 | * There is a standard hashed waitqueue table for generic use. This | |
501 | * is the part of the hashtable's accessor API that waits on a bit | |
502 | * when one intends to set it, for instance, trying to lock bitflags. | |
503 | * For instance, if one were to have waiters trying to set bitflag | |
504 | * and waiting for it to clear before setting it, one would call | |
505 | * wait_on_bit() in threads waiting to be able to set the bit. | |
506 | * One uses wait_on_bit_lock() where one is waiting for the bit to | |
507 | * clear with the intention of setting it, and when done, clearing it. | |
508 | */ | |
509 | static inline int wait_on_bit_lock(void *word, int bit, | |
510 | int (*action)(void *), unsigned mode) | |
511 | { | |
512 | if (!test_and_set_bit(bit, word)) | |
513 | return 0; | |
514 | return out_of_line_wait_on_bit_lock(word, bit, action, mode); | |
515 | } | |
516 | ||
517 | #endif /* __KERNEL__ */ | |
518 | ||
519 | #endif |