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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
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 */
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700118#define is_sync_wait(wait) (!(wait) || ((wait)->private))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
120extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
121extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
122extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
123
124static 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 */
132static 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
138static inline void __remove_wait_queue(wait_queue_head_t *head,
139 wait_queue_t *old)
140{
141 list_del(&old->task_list);
142}
143
144void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key));
145extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
146extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
147void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int));
148int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
149int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
150void FASTCALL(wake_up_bit(void *, int));
151int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
152int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
153wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int));
154
155#define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL)
156#define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL)
157#define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL)
158#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
159#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
160#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
161#define wake_up_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE)
162#define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)
163
164#define __wait_event(wq, condition) \
165do { \
166 DEFINE_WAIT(__wait); \
167 \
168 for (;;) { \
169 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
170 if (condition) \
171 break; \
172 schedule(); \
173 } \
174 finish_wait(&wq, &__wait); \
175} while (0)
176
177/**
178 * wait_event - sleep until a condition gets true
179 * @wq: the waitqueue to wait on
180 * @condition: a C expression for the event to wait for
181 *
182 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
183 * @condition evaluates to true. The @condition is checked each time
184 * the waitqueue @wq is woken up.
185 *
186 * wake_up() has to be called after changing any variable that could
187 * change the result of the wait condition.
188 */
189#define wait_event(wq, condition) \
190do { \
191 if (condition) \
192 break; \
193 __wait_event(wq, condition); \
194} while (0)
195
196#define __wait_event_timeout(wq, condition, ret) \
197do { \
198 DEFINE_WAIT(__wait); \
199 \
200 for (;;) { \
201 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
202 if (condition) \
203 break; \
204 ret = schedule_timeout(ret); \
205 if (!ret) \
206 break; \
207 } \
208 finish_wait(&wq, &__wait); \
209} while (0)
210
211/**
212 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
213 * @wq: the waitqueue to wait on
214 * @condition: a C expression for the event to wait for
215 * @timeout: timeout, in jiffies
216 *
217 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
218 * @condition evaluates to true. The @condition is checked each time
219 * the waitqueue @wq is woken up.
220 *
221 * wake_up() has to be called after changing any variable that could
222 * change the result of the wait condition.
223 *
224 * The function returns 0 if the @timeout elapsed, and the remaining
225 * jiffies if the condition evaluated to true before the timeout elapsed.
226 */
227#define wait_event_timeout(wq, condition, timeout) \
228({ \
229 long __ret = timeout; \
230 if (!(condition)) \
231 __wait_event_timeout(wq, condition, __ret); \
232 __ret; \
233})
234
235#define __wait_event_interruptible(wq, condition, ret) \
236do { \
237 DEFINE_WAIT(__wait); \
238 \
239 for (;;) { \
240 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
241 if (condition) \
242 break; \
243 if (!signal_pending(current)) { \
244 schedule(); \
245 continue; \
246 } \
247 ret = -ERESTARTSYS; \
248 break; \
249 } \
250 finish_wait(&wq, &__wait); \
251} while (0)
252
253/**
254 * wait_event_interruptible - sleep until a condition gets true
255 * @wq: the waitqueue to wait on
256 * @condition: a C expression for the event to wait for
257 *
258 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
259 * @condition evaluates to true or a signal is received.
260 * The @condition is checked each time the waitqueue @wq is woken up.
261 *
262 * wake_up() has to be called after changing any variable that could
263 * change the result of the wait condition.
264 *
265 * The function will return -ERESTARTSYS if it was interrupted by a
266 * signal and 0 if @condition evaluated to true.
267 */
268#define wait_event_interruptible(wq, condition) \
269({ \
270 int __ret = 0; \
271 if (!(condition)) \
272 __wait_event_interruptible(wq, condition, __ret); \
273 __ret; \
274})
275
276#define __wait_event_interruptible_timeout(wq, condition, ret) \
277do { \
278 DEFINE_WAIT(__wait); \
279 \
280 for (;;) { \
281 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
282 if (condition) \
283 break; \
284 if (!signal_pending(current)) { \
285 ret = schedule_timeout(ret); \
286 if (!ret) \
287 break; \
288 continue; \
289 } \
290 ret = -ERESTARTSYS; \
291 break; \
292 } \
293 finish_wait(&wq, &__wait); \
294} while (0)
295
296/**
297 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
298 * @wq: the waitqueue to wait on
299 * @condition: a C expression for the event to wait for
300 * @timeout: timeout, in jiffies
301 *
302 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
303 * @condition evaluates to true or a signal is received.
304 * The @condition is checked each time the waitqueue @wq is woken up.
305 *
306 * wake_up() has to be called after changing any variable that could
307 * change the result of the wait condition.
308 *
309 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
310 * was interrupted by a signal, and the remaining jiffies otherwise
311 * if the condition evaluated to true before the timeout elapsed.
312 */
313#define wait_event_interruptible_timeout(wq, condition, timeout) \
314({ \
315 long __ret = timeout; \
316 if (!(condition)) \
317 __wait_event_interruptible_timeout(wq, condition, __ret); \
318 __ret; \
319})
320
321#define __wait_event_interruptible_exclusive(wq, condition, ret) \
322do { \
323 DEFINE_WAIT(__wait); \
324 \
325 for (;;) { \
326 prepare_to_wait_exclusive(&wq, &__wait, \
327 TASK_INTERRUPTIBLE); \
328 if (condition) \
329 break; \
330 if (!signal_pending(current)) { \
331 schedule(); \
332 continue; \
333 } \
334 ret = -ERESTARTSYS; \
335 break; \
336 } \
337 finish_wait(&wq, &__wait); \
338} while (0)
339
340#define wait_event_interruptible_exclusive(wq, condition) \
341({ \
342 int __ret = 0; \
343 if (!(condition)) \
344 __wait_event_interruptible_exclusive(wq, condition, __ret);\
345 __ret; \
346})
347
348/*
349 * Must be called with the spinlock in the wait_queue_head_t held.
350 */
351static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
352 wait_queue_t * wait)
353{
354 wait->flags |= WQ_FLAG_EXCLUSIVE;
355 __add_wait_queue_tail(q, wait);
356}
357
358/*
359 * Must be called with the spinlock in the wait_queue_head_t held.
360 */
361static inline void remove_wait_queue_locked(wait_queue_head_t *q,
362 wait_queue_t * wait)
363{
364 __remove_wait_queue(q, wait);
365}
366
367/*
368 * These are the old interfaces to sleep waiting for an event.
Ingo Molnar0fec1712007-07-09 18:52:01 +0200369 * They are racy. DO NOT use them, use the wait_event* interfaces above.
370 * We plan to remove these interfaces.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 */
Ingo Molnar0fec1712007-07-09 18:52:01 +0200372extern void sleep_on(wait_queue_head_t *q);
373extern long sleep_on_timeout(wait_queue_head_t *q,
374 signed long timeout);
375extern void interruptible_sleep_on(wait_queue_head_t *q);
376extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
377 signed long timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379/*
380 * Waitqueues which are removed from the waitqueue_head at wakeup time
381 */
382void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
383 wait_queue_t *wait, int state));
384void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
385 wait_queue_t *wait, int state));
386void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
387int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
388int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
389
390#define DEFINE_WAIT(name) \
391 wait_queue_t name = { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700392 .private = current, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 .func = autoremove_wake_function, \
blaisorblade@yahoo.it7e43c842005-05-25 01:31:42 +0200394 .task_list = LIST_HEAD_INIT((name).task_list), \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 }
396
397#define DEFINE_WAIT_BIT(name, word, bit) \
398 struct wait_bit_queue name = { \
399 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
400 .wait = { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700401 .private = current, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 .func = wake_bit_function, \
403 .task_list = \
404 LIST_HEAD_INIT((name).wait.task_list), \
405 }, \
406 }
407
408#define init_wait(wait) \
409 do { \
Benjamin LaHaisec43dc2f2005-06-23 00:10:27 -0700410 (wait)->private = current; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 (wait)->func = autoremove_wake_function; \
412 INIT_LIST_HEAD(&(wait)->task_list); \
413 } while (0)
414
415/**
416 * wait_on_bit - wait for a bit to be cleared
417 * @word: the word being waited on, a kernel virtual address
418 * @bit: the bit of the word being waited on
419 * @action: the function used to sleep, which may take special actions
420 * @mode: the task state to sleep in
421 *
422 * There is a standard hashed waitqueue table for generic use. This
423 * is the part of the hashtable's accessor API that waits on a bit.
424 * For instance, if one were to have waiters on a bitflag, one would
425 * call wait_on_bit() in threads waiting for the bit to clear.
426 * One uses wait_on_bit() where one is waiting for the bit to clear,
427 * but has no intention of setting it.
428 */
429static inline int wait_on_bit(void *word, int bit,
430 int (*action)(void *), unsigned mode)
431{
432 if (!test_bit(bit, word))
433 return 0;
434 return out_of_line_wait_on_bit(word, bit, action, mode);
435}
436
437/**
438 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
439 * @word: the word being waited on, a kernel virtual address
440 * @bit: the bit of the word being waited on
441 * @action: the function used to sleep, which may take special actions
442 * @mode: the task state to sleep in
443 *
444 * There is a standard hashed waitqueue table for generic use. This
445 * is the part of the hashtable's accessor API that waits on a bit
446 * when one intends to set it, for instance, trying to lock bitflags.
447 * For instance, if one were to have waiters trying to set bitflag
448 * and waiting for it to clear before setting it, one would call
449 * wait_on_bit() in threads waiting to be able to set the bit.
450 * One uses wait_on_bit_lock() where one is waiting for the bit to
451 * clear with the intention of setting it, and when done, clearing it.
452 */
453static inline int wait_on_bit_lock(void *word, int bit,
454 int (*action)(void *), unsigned mode)
455{
456 if (!test_and_set_bit(bit, word))
457 return 0;
458 return out_of_line_wait_on_bit_lock(word, bit, action, mode);
459}
460
461#endif /* __KERNEL__ */
462
463#endif