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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 LT |
119 | |
120 | extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)); | |
121 | extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait)); | |
122 | extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)); | |
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 | ||
144 | void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key)); | |
145 | extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode)); | |
146 | extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr)); | |
147 | void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int)); | |
148 | int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); | |
149 | int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); | |
150 | void FASTCALL(wake_up_bit(void *, int)); | |
151 | int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned)); | |
152 | int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned)); | |
153 | wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int)); | |
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 LT |
164 | |
165 | #define __wait_event(wq, condition) \ | |
166 | do { \ | |
167 | DEFINE_WAIT(__wait); \ | |
168 | \ | |
169 | for (;;) { \ | |
170 | prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ | |
171 | if (condition) \ | |
172 | break; \ | |
173 | schedule(); \ | |
174 | } \ | |
175 | finish_wait(&wq, &__wait); \ | |
176 | } while (0) | |
177 | ||
178 | /** | |
179 | * wait_event - sleep until a condition gets true | |
180 | * @wq: the waitqueue to wait on | |
181 | * @condition: a C expression for the event to wait for | |
182 | * | |
183 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
184 | * @condition evaluates to true. The @condition is checked each time | |
185 | * the waitqueue @wq is woken up. | |
186 | * | |
187 | * wake_up() has to be called after changing any variable that could | |
188 | * change the result of the wait condition. | |
189 | */ | |
190 | #define wait_event(wq, condition) \ | |
191 | do { \ | |
192 | if (condition) \ | |
193 | break; \ | |
194 | __wait_event(wq, condition); \ | |
195 | } while (0) | |
196 | ||
197 | #define __wait_event_timeout(wq, condition, ret) \ | |
198 | do { \ | |
199 | DEFINE_WAIT(__wait); \ | |
200 | \ | |
201 | for (;;) { \ | |
202 | prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ | |
203 | if (condition) \ | |
204 | break; \ | |
205 | ret = schedule_timeout(ret); \ | |
206 | if (!ret) \ | |
207 | break; \ | |
208 | } \ | |
209 | finish_wait(&wq, &__wait); \ | |
210 | } while (0) | |
211 | ||
212 | /** | |
213 | * wait_event_timeout - sleep until a condition gets true or a timeout elapses | |
214 | * @wq: the waitqueue to wait on | |
215 | * @condition: a C expression for the event to wait for | |
216 | * @timeout: timeout, in jiffies | |
217 | * | |
218 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
219 | * @condition evaluates to true. The @condition is checked each time | |
220 | * the waitqueue @wq is woken up. | |
221 | * | |
222 | * wake_up() has to be called after changing any variable that could | |
223 | * change the result of the wait condition. | |
224 | * | |
225 | * The function returns 0 if the @timeout elapsed, and the remaining | |
226 | * jiffies if the condition evaluated to true before the timeout elapsed. | |
227 | */ | |
228 | #define wait_event_timeout(wq, condition, timeout) \ | |
229 | ({ \ | |
230 | long __ret = timeout; \ | |
231 | if (!(condition)) \ | |
232 | __wait_event_timeout(wq, condition, __ret); \ | |
233 | __ret; \ | |
234 | }) | |
235 | ||
236 | #define __wait_event_interruptible(wq, condition, ret) \ | |
237 | do { \ | |
238 | DEFINE_WAIT(__wait); \ | |
239 | \ | |
240 | for (;;) { \ | |
241 | prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ | |
242 | if (condition) \ | |
243 | break; \ | |
244 | if (!signal_pending(current)) { \ | |
245 | schedule(); \ | |
246 | continue; \ | |
247 | } \ | |
248 | ret = -ERESTARTSYS; \ | |
249 | break; \ | |
250 | } \ | |
251 | finish_wait(&wq, &__wait); \ | |
252 | } while (0) | |
253 | ||
254 | /** | |
255 | * wait_event_interruptible - sleep until a condition gets true | |
256 | * @wq: the waitqueue to wait on | |
257 | * @condition: a C expression for the event to wait for | |
258 | * | |
259 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
260 | * @condition evaluates to true or a signal is received. | |
261 | * The @condition is checked each time the waitqueue @wq is woken up. | |
262 | * | |
263 | * wake_up() has to be called after changing any variable that could | |
264 | * change the result of the wait condition. | |
265 | * | |
266 | * The function will return -ERESTARTSYS if it was interrupted by a | |
267 | * signal and 0 if @condition evaluated to true. | |
268 | */ | |
269 | #define wait_event_interruptible(wq, condition) \ | |
270 | ({ \ | |
271 | int __ret = 0; \ | |
272 | if (!(condition)) \ | |
273 | __wait_event_interruptible(wq, condition, __ret); \ | |
274 | __ret; \ | |
275 | }) | |
276 | ||
277 | #define __wait_event_interruptible_timeout(wq, condition, ret) \ | |
278 | do { \ | |
279 | DEFINE_WAIT(__wait); \ | |
280 | \ | |
281 | for (;;) { \ | |
282 | prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ | |
283 | if (condition) \ | |
284 | break; \ | |
285 | if (!signal_pending(current)) { \ | |
286 | ret = schedule_timeout(ret); \ | |
287 | if (!ret) \ | |
288 | break; \ | |
289 | continue; \ | |
290 | } \ | |
291 | ret = -ERESTARTSYS; \ | |
292 | break; \ | |
293 | } \ | |
294 | finish_wait(&wq, &__wait); \ | |
295 | } while (0) | |
296 | ||
297 | /** | |
298 | * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses | |
299 | * @wq: the waitqueue to wait on | |
300 | * @condition: a C expression for the event to wait for | |
301 | * @timeout: timeout, in jiffies | |
302 | * | |
303 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
304 | * @condition evaluates to true or a signal is received. | |
305 | * The @condition is checked each time the waitqueue @wq is woken up. | |
306 | * | |
307 | * wake_up() has to be called after changing any variable that could | |
308 | * change the result of the wait condition. | |
309 | * | |
310 | * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it | |
311 | * was interrupted by a signal, and the remaining jiffies otherwise | |
312 | * if the condition evaluated to true before the timeout elapsed. | |
313 | */ | |
314 | #define wait_event_interruptible_timeout(wq, condition, timeout) \ | |
315 | ({ \ | |
316 | long __ret = timeout; \ | |
317 | if (!(condition)) \ | |
318 | __wait_event_interruptible_timeout(wq, condition, __ret); \ | |
319 | __ret; \ | |
320 | }) | |
321 | ||
322 | #define __wait_event_interruptible_exclusive(wq, condition, ret) \ | |
323 | do { \ | |
324 | DEFINE_WAIT(__wait); \ | |
325 | \ | |
326 | for (;;) { \ | |
327 | prepare_to_wait_exclusive(&wq, &__wait, \ | |
328 | TASK_INTERRUPTIBLE); \ | |
329 | if (condition) \ | |
330 | break; \ | |
331 | if (!signal_pending(current)) { \ | |
332 | schedule(); \ | |
333 | continue; \ | |
334 | } \ | |
335 | ret = -ERESTARTSYS; \ | |
336 | break; \ | |
337 | } \ | |
338 | finish_wait(&wq, &__wait); \ | |
339 | } while (0) | |
340 | ||
341 | #define wait_event_interruptible_exclusive(wq, condition) \ | |
342 | ({ \ | |
343 | int __ret = 0; \ | |
344 | if (!(condition)) \ | |
345 | __wait_event_interruptible_exclusive(wq, condition, __ret);\ | |
346 | __ret; \ | |
347 | }) | |
348 | ||
1411d5a7 MW |
349 | #define __wait_event_killable(wq, condition, ret) \ |
350 | do { \ | |
351 | DEFINE_WAIT(__wait); \ | |
352 | \ | |
353 | for (;;) { \ | |
354 | prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \ | |
355 | if (condition) \ | |
356 | break; \ | |
357 | if (!fatal_signal_pending(current)) { \ | |
358 | schedule(); \ | |
359 | continue; \ | |
360 | } \ | |
361 | ret = -ERESTARTSYS; \ | |
362 | break; \ | |
363 | } \ | |
364 | finish_wait(&wq, &__wait); \ | |
365 | } while (0) | |
366 | ||
367 | /** | |
368 | * wait_event_killable - sleep until a condition gets true | |
369 | * @wq: the waitqueue to wait on | |
370 | * @condition: a C expression for the event to wait for | |
371 | * | |
372 | * The process is put to sleep (TASK_KILLABLE) until the | |
373 | * @condition evaluates to true or a signal is received. | |
374 | * The @condition is checked each time the waitqueue @wq is woken up. | |
375 | * | |
376 | * wake_up() has to be called after changing any variable that could | |
377 | * change the result of the wait condition. | |
378 | * | |
379 | * The function will return -ERESTARTSYS if it was interrupted by a | |
380 | * signal and 0 if @condition evaluated to true. | |
381 | */ | |
382 | #define wait_event_killable(wq, condition) \ | |
383 | ({ \ | |
384 | int __ret = 0; \ | |
385 | if (!(condition)) \ | |
386 | __wait_event_killable(wq, condition, __ret); \ | |
387 | __ret; \ | |
388 | }) | |
389 | ||
1da177e4 LT |
390 | /* |
391 | * Must be called with the spinlock in the wait_queue_head_t held. | |
392 | */ | |
393 | static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q, | |
394 | wait_queue_t * wait) | |
395 | { | |
396 | wait->flags |= WQ_FLAG_EXCLUSIVE; | |
397 | __add_wait_queue_tail(q, wait); | |
398 | } | |
399 | ||
400 | /* | |
401 | * Must be called with the spinlock in the wait_queue_head_t held. | |
402 | */ | |
403 | static inline void remove_wait_queue_locked(wait_queue_head_t *q, | |
404 | wait_queue_t * wait) | |
405 | { | |
406 | __remove_wait_queue(q, wait); | |
407 | } | |
408 | ||
409 | /* | |
410 | * These are the old interfaces to sleep waiting for an event. | |
0fec171c IM |
411 | * They are racy. DO NOT use them, use the wait_event* interfaces above. |
412 | * We plan to remove these interfaces. | |
1da177e4 | 413 | */ |
0fec171c IM |
414 | extern void sleep_on(wait_queue_head_t *q); |
415 | extern long sleep_on_timeout(wait_queue_head_t *q, | |
416 | signed long timeout); | |
417 | extern void interruptible_sleep_on(wait_queue_head_t *q); | |
418 | extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, | |
419 | signed long timeout); | |
1da177e4 LT |
420 | |
421 | /* | |
422 | * Waitqueues which are removed from the waitqueue_head at wakeup time | |
423 | */ | |
424 | void FASTCALL(prepare_to_wait(wait_queue_head_t *q, | |
425 | wait_queue_t *wait, int state)); | |
426 | void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q, | |
427 | wait_queue_t *wait, int state)); | |
428 | void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait)); | |
429 | int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
430 | int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
431 | ||
432 | #define DEFINE_WAIT(name) \ | |
433 | wait_queue_t name = { \ | |
c43dc2fd | 434 | .private = current, \ |
1da177e4 | 435 | .func = autoremove_wake_function, \ |
7e43c84e | 436 | .task_list = LIST_HEAD_INIT((name).task_list), \ |
1da177e4 LT |
437 | } |
438 | ||
439 | #define DEFINE_WAIT_BIT(name, word, bit) \ | |
440 | struct wait_bit_queue name = { \ | |
441 | .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ | |
442 | .wait = { \ | |
c43dc2fd | 443 | .private = current, \ |
1da177e4 LT |
444 | .func = wake_bit_function, \ |
445 | .task_list = \ | |
446 | LIST_HEAD_INIT((name).wait.task_list), \ | |
447 | }, \ | |
448 | } | |
449 | ||
450 | #define init_wait(wait) \ | |
451 | do { \ | |
c43dc2fd | 452 | (wait)->private = current; \ |
1da177e4 LT |
453 | (wait)->func = autoremove_wake_function; \ |
454 | INIT_LIST_HEAD(&(wait)->task_list); \ | |
455 | } while (0) | |
456 | ||
457 | /** | |
458 | * wait_on_bit - wait for a bit to be cleared | |
459 | * @word: the word being waited on, a kernel virtual address | |
460 | * @bit: the bit of the word being waited on | |
461 | * @action: the function used to sleep, which may take special actions | |
462 | * @mode: the task state to sleep in | |
463 | * | |
464 | * There is a standard hashed waitqueue table for generic use. This | |
465 | * is the part of the hashtable's accessor API that waits on a bit. | |
466 | * For instance, if one were to have waiters on a bitflag, one would | |
467 | * call wait_on_bit() in threads waiting for the bit to clear. | |
468 | * One uses wait_on_bit() where one is waiting for the bit to clear, | |
469 | * but has no intention of setting it. | |
470 | */ | |
471 | static inline int wait_on_bit(void *word, int bit, | |
472 | int (*action)(void *), unsigned mode) | |
473 | { | |
474 | if (!test_bit(bit, word)) | |
475 | return 0; | |
476 | return out_of_line_wait_on_bit(word, bit, action, mode); | |
477 | } | |
478 | ||
479 | /** | |
480 | * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it | |
481 | * @word: the word being waited on, a kernel virtual address | |
482 | * @bit: the bit of the word being waited on | |
483 | * @action: the function used to sleep, which may take special actions | |
484 | * @mode: the task state to sleep in | |
485 | * | |
486 | * There is a standard hashed waitqueue table for generic use. This | |
487 | * is the part of the hashtable's accessor API that waits on a bit | |
488 | * when one intends to set it, for instance, trying to lock bitflags. | |
489 | * For instance, if one were to have waiters trying to set bitflag | |
490 | * and waiting for it to clear before setting it, one would call | |
491 | * wait_on_bit() in threads waiting to be able to set the bit. | |
492 | * One uses wait_on_bit_lock() where one is waiting for the bit to | |
493 | * clear with the intention of setting it, and when done, clearing it. | |
494 | */ | |
495 | static inline int wait_on_bit_lock(void *word, int bit, | |
496 | int (*action)(void *), unsigned mode) | |
497 | { | |
498 | if (!test_and_set_bit(bit, word)) | |
499 | return 0; | |
500 | return out_of_line_wait_on_bit_lock(word, bit, action, mode); | |
501 | } | |
502 | ||
503 | #endif /* __KERNEL__ */ | |
504 | ||
505 | #endif |