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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 | ||
22 | #include <linux/config.h> | |
23 | #include <linux/list.h> | |
24 | #include <linux/stddef.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <asm/system.h> | |
27 | #include <asm/current.h> | |
28 | ||
29 | typedef struct __wait_queue wait_queue_t; | |
30 | typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
31 | int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
32 | ||
33 | struct __wait_queue { | |
34 | unsigned int flags; | |
35 | #define WQ_FLAG_EXCLUSIVE 0x01 | |
c43dc2fd | 36 | void *private; |
1da177e4 LT |
37 | wait_queue_func_t func; |
38 | struct list_head task_list; | |
39 | }; | |
40 | ||
41 | struct wait_bit_key { | |
42 | void *flags; | |
43 | int bit_nr; | |
44 | }; | |
45 | ||
46 | struct wait_bit_queue { | |
47 | struct wait_bit_key key; | |
48 | wait_queue_t wait; | |
49 | }; | |
50 | ||
51 | struct __wait_queue_head { | |
52 | spinlock_t lock; | |
53 | struct list_head task_list; | |
54 | }; | |
55 | typedef struct __wait_queue_head wait_queue_head_t; | |
56 | ||
8c65b4a6 | 57 | struct task_struct; |
1da177e4 LT |
58 | |
59 | /* | |
60 | * Macros for declaration and initialisaton of the datatypes | |
61 | */ | |
62 | ||
63 | #define __WAITQUEUE_INITIALIZER(name, tsk) { \ | |
c43dc2fd | 64 | .private = tsk, \ |
1da177e4 LT |
65 | .func = default_wake_function, \ |
66 | .task_list = { NULL, NULL } } | |
67 | ||
68 | #define DECLARE_WAITQUEUE(name, tsk) \ | |
69 | wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk) | |
70 | ||
71 | #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ | |
72 | .lock = SPIN_LOCK_UNLOCKED, \ | |
73 | .task_list = { &(name).task_list, &(name).task_list } } | |
74 | ||
75 | #define DECLARE_WAIT_QUEUE_HEAD(name) \ | |
76 | wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name) | |
77 | ||
78 | #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \ | |
79 | { .flags = word, .bit_nr = bit, } | |
80 | ||
81 | static inline void init_waitqueue_head(wait_queue_head_t *q) | |
82 | { | |
83 | spin_lock_init(&q->lock); | |
84 | INIT_LIST_HEAD(&q->task_list); | |
85 | } | |
86 | ||
87 | static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) | |
88 | { | |
89 | q->flags = 0; | |
c43dc2fd | 90 | q->private = p; |
1da177e4 LT |
91 | q->func = default_wake_function; |
92 | } | |
93 | ||
94 | static inline void init_waitqueue_func_entry(wait_queue_t *q, | |
95 | wait_queue_func_t func) | |
96 | { | |
97 | q->flags = 0; | |
c43dc2fd | 98 | q->private = NULL; |
1da177e4 LT |
99 | q->func = func; |
100 | } | |
101 | ||
102 | static inline int waitqueue_active(wait_queue_head_t *q) | |
103 | { | |
104 | return !list_empty(&q->task_list); | |
105 | } | |
106 | ||
107 | /* | |
108 | * Used to distinguish between sync and async io wait context: | |
109 | * sync i/o typically specifies a NULL wait queue entry or a wait | |
110 | * queue entry bound to a task (current task) to wake up. | |
111 | * aio specifies a wait queue entry with an async notification | |
112 | * callback routine, not associated with any task. | |
113 | */ | |
c43dc2fd | 114 | #define is_sync_wait(wait) (!(wait) || ((wait)->private)) |
1da177e4 LT |
115 | |
116 | extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)); | |
117 | extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait)); | |
118 | extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)); | |
119 | ||
120 | static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) | |
121 | { | |
122 | list_add(&new->task_list, &head->task_list); | |
123 | } | |
124 | ||
125 | /* | |
126 | * Used for wake-one threads: | |
127 | */ | |
128 | static inline void __add_wait_queue_tail(wait_queue_head_t *head, | |
129 | wait_queue_t *new) | |
130 | { | |
131 | list_add_tail(&new->task_list, &head->task_list); | |
132 | } | |
133 | ||
134 | static inline void __remove_wait_queue(wait_queue_head_t *head, | |
135 | wait_queue_t *old) | |
136 | { | |
137 | list_del(&old->task_list); | |
138 | } | |
139 | ||
140 | void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key)); | |
141 | extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode)); | |
142 | extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr)); | |
143 | void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int)); | |
144 | int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); | |
145 | int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); | |
146 | void FASTCALL(wake_up_bit(void *, int)); | |
147 | int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned)); | |
148 | int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned)); | |
149 | wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int)); | |
150 | ||
151 | #define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL) | |
152 | #define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL) | |
153 | #define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL) | |
154 | #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) | |
155 | #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) | |
156 | #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) | |
157 | #define wake_up_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE) | |
158 | #define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1) | |
159 | ||
160 | #define __wait_event(wq, condition) \ | |
161 | do { \ | |
162 | DEFINE_WAIT(__wait); \ | |
163 | \ | |
164 | for (;;) { \ | |
165 | prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ | |
166 | if (condition) \ | |
167 | break; \ | |
168 | schedule(); \ | |
169 | } \ | |
170 | finish_wait(&wq, &__wait); \ | |
171 | } while (0) | |
172 | ||
173 | /** | |
174 | * wait_event - sleep until a condition gets true | |
175 | * @wq: the waitqueue to wait on | |
176 | * @condition: a C expression for the event to wait for | |
177 | * | |
178 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
179 | * @condition evaluates to true. The @condition is checked each time | |
180 | * the waitqueue @wq is woken up. | |
181 | * | |
182 | * wake_up() has to be called after changing any variable that could | |
183 | * change the result of the wait condition. | |
184 | */ | |
185 | #define wait_event(wq, condition) \ | |
186 | do { \ | |
187 | if (condition) \ | |
188 | break; \ | |
189 | __wait_event(wq, condition); \ | |
190 | } while (0) | |
191 | ||
192 | #define __wait_event_timeout(wq, condition, ret) \ | |
193 | do { \ | |
194 | DEFINE_WAIT(__wait); \ | |
195 | \ | |
196 | for (;;) { \ | |
197 | prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ | |
198 | if (condition) \ | |
199 | break; \ | |
200 | ret = schedule_timeout(ret); \ | |
201 | if (!ret) \ | |
202 | break; \ | |
203 | } \ | |
204 | finish_wait(&wq, &__wait); \ | |
205 | } while (0) | |
206 | ||
207 | /** | |
208 | * wait_event_timeout - sleep until a condition gets true or a timeout elapses | |
209 | * @wq: the waitqueue to wait on | |
210 | * @condition: a C expression for the event to wait for | |
211 | * @timeout: timeout, in jiffies | |
212 | * | |
213 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
214 | * @condition evaluates to true. The @condition is checked each time | |
215 | * the waitqueue @wq is woken up. | |
216 | * | |
217 | * wake_up() has to be called after changing any variable that could | |
218 | * change the result of the wait condition. | |
219 | * | |
220 | * The function returns 0 if the @timeout elapsed, and the remaining | |
221 | * jiffies if the condition evaluated to true before the timeout elapsed. | |
222 | */ | |
223 | #define wait_event_timeout(wq, condition, timeout) \ | |
224 | ({ \ | |
225 | long __ret = timeout; \ | |
226 | if (!(condition)) \ | |
227 | __wait_event_timeout(wq, condition, __ret); \ | |
228 | __ret; \ | |
229 | }) | |
230 | ||
231 | #define __wait_event_interruptible(wq, condition, ret) \ | |
232 | do { \ | |
233 | DEFINE_WAIT(__wait); \ | |
234 | \ | |
235 | for (;;) { \ | |
236 | prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ | |
237 | if (condition) \ | |
238 | break; \ | |
239 | if (!signal_pending(current)) { \ | |
240 | schedule(); \ | |
241 | continue; \ | |
242 | } \ | |
243 | ret = -ERESTARTSYS; \ | |
244 | break; \ | |
245 | } \ | |
246 | finish_wait(&wq, &__wait); \ | |
247 | } while (0) | |
248 | ||
249 | /** | |
250 | * wait_event_interruptible - sleep until a condition gets true | |
251 | * @wq: the waitqueue to wait on | |
252 | * @condition: a C expression for the event to wait for | |
253 | * | |
254 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
255 | * @condition evaluates to true or a signal is received. | |
256 | * The @condition is checked each time the waitqueue @wq is woken up. | |
257 | * | |
258 | * wake_up() has to be called after changing any variable that could | |
259 | * change the result of the wait condition. | |
260 | * | |
261 | * The function will return -ERESTARTSYS if it was interrupted by a | |
262 | * signal and 0 if @condition evaluated to true. | |
263 | */ | |
264 | #define wait_event_interruptible(wq, condition) \ | |
265 | ({ \ | |
266 | int __ret = 0; \ | |
267 | if (!(condition)) \ | |
268 | __wait_event_interruptible(wq, condition, __ret); \ | |
269 | __ret; \ | |
270 | }) | |
271 | ||
272 | #define __wait_event_interruptible_timeout(wq, condition, ret) \ | |
273 | do { \ | |
274 | DEFINE_WAIT(__wait); \ | |
275 | \ | |
276 | for (;;) { \ | |
277 | prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ | |
278 | if (condition) \ | |
279 | break; \ | |
280 | if (!signal_pending(current)) { \ | |
281 | ret = schedule_timeout(ret); \ | |
282 | if (!ret) \ | |
283 | break; \ | |
284 | continue; \ | |
285 | } \ | |
286 | ret = -ERESTARTSYS; \ | |
287 | break; \ | |
288 | } \ | |
289 | finish_wait(&wq, &__wait); \ | |
290 | } while (0) | |
291 | ||
292 | /** | |
293 | * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses | |
294 | * @wq: the waitqueue to wait on | |
295 | * @condition: a C expression for the event to wait for | |
296 | * @timeout: timeout, in jiffies | |
297 | * | |
298 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
299 | * @condition evaluates to true or a signal is received. | |
300 | * The @condition is checked each time the waitqueue @wq is woken up. | |
301 | * | |
302 | * wake_up() has to be called after changing any variable that could | |
303 | * change the result of the wait condition. | |
304 | * | |
305 | * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it | |
306 | * was interrupted by a signal, and the remaining jiffies otherwise | |
307 | * if the condition evaluated to true before the timeout elapsed. | |
308 | */ | |
309 | #define wait_event_interruptible_timeout(wq, condition, timeout) \ | |
310 | ({ \ | |
311 | long __ret = timeout; \ | |
312 | if (!(condition)) \ | |
313 | __wait_event_interruptible_timeout(wq, condition, __ret); \ | |
314 | __ret; \ | |
315 | }) | |
316 | ||
317 | #define __wait_event_interruptible_exclusive(wq, condition, ret) \ | |
318 | do { \ | |
319 | DEFINE_WAIT(__wait); \ | |
320 | \ | |
321 | for (;;) { \ | |
322 | prepare_to_wait_exclusive(&wq, &__wait, \ | |
323 | TASK_INTERRUPTIBLE); \ | |
324 | if (condition) \ | |
325 | break; \ | |
326 | if (!signal_pending(current)) { \ | |
327 | schedule(); \ | |
328 | continue; \ | |
329 | } \ | |
330 | ret = -ERESTARTSYS; \ | |
331 | break; \ | |
332 | } \ | |
333 | finish_wait(&wq, &__wait); \ | |
334 | } while (0) | |
335 | ||
336 | #define wait_event_interruptible_exclusive(wq, condition) \ | |
337 | ({ \ | |
338 | int __ret = 0; \ | |
339 | if (!(condition)) \ | |
340 | __wait_event_interruptible_exclusive(wq, condition, __ret);\ | |
341 | __ret; \ | |
342 | }) | |
343 | ||
344 | /* | |
345 | * Must be called with the spinlock in the wait_queue_head_t held. | |
346 | */ | |
347 | static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q, | |
348 | wait_queue_t * wait) | |
349 | { | |
350 | wait->flags |= WQ_FLAG_EXCLUSIVE; | |
351 | __add_wait_queue_tail(q, wait); | |
352 | } | |
353 | ||
354 | /* | |
355 | * Must be called with the spinlock in the wait_queue_head_t held. | |
356 | */ | |
357 | static inline void remove_wait_queue_locked(wait_queue_head_t *q, | |
358 | wait_queue_t * wait) | |
359 | { | |
360 | __remove_wait_queue(q, wait); | |
361 | } | |
362 | ||
363 | /* | |
364 | * These are the old interfaces to sleep waiting for an event. | |
365 | * They are racy. DO NOT use them, use the wait_event* interfaces above. | |
366 | * We plan to remove these interfaces during 2.7. | |
367 | */ | |
368 | extern void FASTCALL(sleep_on(wait_queue_head_t *q)); | |
369 | extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q, | |
370 | signed long timeout)); | |
371 | extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q)); | |
372 | extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q, | |
373 | signed long timeout)); | |
374 | ||
375 | /* | |
376 | * Waitqueues which are removed from the waitqueue_head at wakeup time | |
377 | */ | |
378 | void FASTCALL(prepare_to_wait(wait_queue_head_t *q, | |
379 | wait_queue_t *wait, int state)); | |
380 | void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q, | |
381 | wait_queue_t *wait, int state)); | |
382 | void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait)); | |
383 | int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
384 | int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
385 | ||
386 | #define DEFINE_WAIT(name) \ | |
387 | wait_queue_t name = { \ | |
c43dc2fd | 388 | .private = current, \ |
1da177e4 | 389 | .func = autoremove_wake_function, \ |
7e43c84e | 390 | .task_list = LIST_HEAD_INIT((name).task_list), \ |
1da177e4 LT |
391 | } |
392 | ||
393 | #define DEFINE_WAIT_BIT(name, word, bit) \ | |
394 | struct wait_bit_queue name = { \ | |
395 | .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ | |
396 | .wait = { \ | |
c43dc2fd | 397 | .private = current, \ |
1da177e4 LT |
398 | .func = wake_bit_function, \ |
399 | .task_list = \ | |
400 | LIST_HEAD_INIT((name).wait.task_list), \ | |
401 | }, \ | |
402 | } | |
403 | ||
404 | #define init_wait(wait) \ | |
405 | do { \ | |
c43dc2fd | 406 | (wait)->private = current; \ |
1da177e4 LT |
407 | (wait)->func = autoremove_wake_function; \ |
408 | INIT_LIST_HEAD(&(wait)->task_list); \ | |
409 | } while (0) | |
410 | ||
411 | /** | |
412 | * wait_on_bit - wait for a bit to be cleared | |
413 | * @word: the word being waited on, a kernel virtual address | |
414 | * @bit: the bit of the word being waited on | |
415 | * @action: the function used to sleep, which may take special actions | |
416 | * @mode: the task state to sleep in | |
417 | * | |
418 | * There is a standard hashed waitqueue table for generic use. This | |
419 | * is the part of the hashtable's accessor API that waits on a bit. | |
420 | * For instance, if one were to have waiters on a bitflag, one would | |
421 | * call wait_on_bit() in threads waiting for the bit to clear. | |
422 | * One uses wait_on_bit() where one is waiting for the bit to clear, | |
423 | * but has no intention of setting it. | |
424 | */ | |
425 | static inline int wait_on_bit(void *word, int bit, | |
426 | int (*action)(void *), unsigned mode) | |
427 | { | |
428 | if (!test_bit(bit, word)) | |
429 | return 0; | |
430 | return out_of_line_wait_on_bit(word, bit, action, mode); | |
431 | } | |
432 | ||
433 | /** | |
434 | * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it | |
435 | * @word: the word being waited on, a kernel virtual address | |
436 | * @bit: the bit of the word being waited on | |
437 | * @action: the function used to sleep, which may take special actions | |
438 | * @mode: the task state to sleep in | |
439 | * | |
440 | * There is a standard hashed waitqueue table for generic use. This | |
441 | * is the part of the hashtable's accessor API that waits on a bit | |
442 | * when one intends to set it, for instance, trying to lock bitflags. | |
443 | * For instance, if one were to have waiters trying to set bitflag | |
444 | * and waiting for it to clear before setting it, one would call | |
445 | * wait_on_bit() in threads waiting to be able to set the bit. | |
446 | * One uses wait_on_bit_lock() where one is waiting for the bit to | |
447 | * clear with the intention of setting it, and when done, clearing it. | |
448 | */ | |
449 | static inline int wait_on_bit_lock(void *word, int bit, | |
450 | int (*action)(void *), unsigned mode) | |
451 | { | |
452 | if (!test_and_set_bit(bit, word)) | |
453 | return 0; | |
454 | return out_of_line_wait_on_bit_lock(word, bit, action, mode); | |
455 | } | |
456 | ||
457 | #endif /* __KERNEL__ */ | |
458 | ||
459 | #endif |