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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 | ||
b3c97528 HH |
111 | extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); |
112 | extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait); | |
113 | extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); | |
1da177e4 LT |
114 | |
115 | static 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 | */ | |
123 | static 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 | ||
129 | static inline void __remove_wait_queue(wait_queue_head_t *head, | |
130 | wait_queue_t *old) | |
131 | { | |
132 | list_del(&old->task_list); | |
133 | } | |
134 | ||
b3c97528 HH |
135 | void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key); |
136 | extern void __wake_up_locked(wait_queue_head_t *q, unsigned int mode); | |
137 | extern void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr); | |
138 | void __wake_up_bit(wait_queue_head_t *, void *, int); | |
139 | int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned); | |
140 | int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned); | |
141 | void wake_up_bit(void *, int); | |
142 | int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned); | |
143 | int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned); | |
144 | wait_queue_head_t *bit_waitqueue(void *, int); | |
1da177e4 | 145 | |
e64d66c8 MW |
146 | #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 | ||
1da177e4 LT |
151 | #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) | |
e64d66c8 | 154 | #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1) |
1da177e4 | 155 | |
0ccf831c PZ |
156 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
157 | /* | |
158 | * macro to avoid include hell | |
159 | */ | |
160 | #define wake_up_nested(x, s) \ | |
161 | do { \ | |
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 | ||
1da177e4 LT |
172 | #define __wait_event(wq, condition) \ |
173 | do { \ | |
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) \ | |
198 | do { \ | |
199 | if (condition) \ | |
200 | break; \ | |
201 | __wait_event(wq, condition); \ | |
202 | } while (0) | |
203 | ||
204 | #define __wait_event_timeout(wq, condition, ret) \ | |
205 | do { \ | |
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) \ | |
244 | do { \ | |
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) \ | |
285 | do { \ | |
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) \ | |
330 | do { \ | |
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 | ||
1411d5a7 MW |
356 | #define __wait_event_killable(wq, condition, ret) \ |
357 | do { \ | |
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 | ||
1da177e4 LT |
397 | /* |
398 | * Must be called with the spinlock in the wait_queue_head_t held. | |
399 | */ | |
400 | static 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 | */ | |
410 | static 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. | |
0fec171c IM |
418 | * They are racy. DO NOT use them, use the wait_event* interfaces above. |
419 | * We plan to remove these interfaces. | |
1da177e4 | 420 | */ |
0fec171c IM |
421 | extern void sleep_on(wait_queue_head_t *q); |
422 | extern long sleep_on_timeout(wait_queue_head_t *q, | |
423 | signed long timeout); | |
424 | extern void interruptible_sleep_on(wait_queue_head_t *q); | |
425 | extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, | |
426 | signed long timeout); | |
1da177e4 LT |
427 | |
428 | /* | |
429 | * Waitqueues which are removed from the waitqueue_head at wakeup time | |
430 | */ | |
b3c97528 HH |
431 | void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); |
432 | void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); | |
433 | void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); | |
1da177e4 LT |
434 | int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); |
435 | int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
436 | ||
437 | #define DEFINE_WAIT(name) \ | |
438 | wait_queue_t name = { \ | |
c43dc2fd | 439 | .private = current, \ |
1da177e4 | 440 | .func = autoremove_wake_function, \ |
7e43c84e | 441 | .task_list = LIST_HEAD_INIT((name).task_list), \ |
1da177e4 LT |
442 | } |
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 = { \ | |
c43dc2fd | 448 | .private = current, \ |
1da177e4 LT |
449 | .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 { \ | |
c43dc2fd | 457 | (wait)->private = current; \ |
1da177e4 LT |
458 | (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 | */ | |
476 | static 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 | */ | |
500 | static 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 |