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wait: Use TASK_NORMAL
[linux-2.6/mini2440.git] / include / linux / wait.h
blob0a410a449258e53b93c0f80b3dbc022a1127c3b0
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/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
35 void *private;
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
56 struct task_struct;
57
58 /*
59 * Macros for declaration and initialisaton of the datatypes
60 */
61
62 #define __WAITQUEUE_INITIALIZER(name, tsk) { \
63 .private = tsk, \
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) { \
71 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
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
80 extern void init_waitqueue_head(wait_queue_head_t *q);
81
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
91 static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
92 {
93 q->flags = 0;
94 q->private = p;
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;
102 q->private = NULL;
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 */
118 #define is_sync_wait(wait) (!(wait) || ((wait)->private))
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
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
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)
163 #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
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
349 /*
350 * Must be called with the spinlock in the wait_queue_head_t held.
351 */
352 static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
353 wait_queue_t * wait)
354 {
355 wait->flags |= WQ_FLAG_EXCLUSIVE;
356 __add_wait_queue_tail(q, wait);
357 }
358
359 /*
360 * Must be called with the spinlock in the wait_queue_head_t held.
361 */
362 static inline void remove_wait_queue_locked(wait_queue_head_t *q,
363 wait_queue_t * wait)
364 {
365 __remove_wait_queue(q, wait);
366 }
367
368 /*
369 * These are the old interfaces to sleep waiting for an event.
370 * They are racy. DO NOT use them, use the wait_event* interfaces above.
371 * We plan to remove these interfaces.
372 */
373 extern void sleep_on(wait_queue_head_t *q);
374 extern long sleep_on_timeout(wait_queue_head_t *q,
375 signed long timeout);
376 extern void interruptible_sleep_on(wait_queue_head_t *q);
377 extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
378 signed long timeout);
379
380 /*
381 * Waitqueues which are removed from the waitqueue_head at wakeup time
382 */
383 void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
384 wait_queue_t *wait, int state));
385 void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
386 wait_queue_t *wait, int state));
387 void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
388 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
389 int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
390
391 #define DEFINE_WAIT(name) \
392 wait_queue_t name = { \
393 .private = current, \
394 .func = autoremove_wake_function, \
395 .task_list = LIST_HEAD_INIT((name).task_list), \
396 }
397
398 #define DEFINE_WAIT_BIT(name, word, bit) \
399 struct wait_bit_queue name = { \
400 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
401 .wait = { \
402 .private = current, \
403 .func = wake_bit_function, \
404 .task_list = \
405 LIST_HEAD_INIT((name).wait.task_list), \
406 }, \
407 }
408
409 #define init_wait(wait) \
410 do { \
411 (wait)->private = current; \
412 (wait)->func = autoremove_wake_function; \
413 INIT_LIST_HEAD(&(wait)->task_list); \
414 } while (0)
415
416 /**
417 * wait_on_bit - wait for a bit to be cleared
418 * @word: the word being waited on, a kernel virtual address
419 * @bit: the bit of the word being waited on
420 * @action: the function used to sleep, which may take special actions
421 * @mode: the task state to sleep in
422 *
423 * There is a standard hashed waitqueue table for generic use. This
424 * is the part of the hashtable's accessor API that waits on a bit.
425 * For instance, if one were to have waiters on a bitflag, one would
426 * call wait_on_bit() in threads waiting for the bit to clear.
427 * One uses wait_on_bit() where one is waiting for the bit to clear,
428 * but has no intention of setting it.
429 */
430 static inline int wait_on_bit(void *word, int bit,
431 int (*action)(void *), unsigned mode)
432 {
433 if (!test_bit(bit, word))
434 return 0;
435 return out_of_line_wait_on_bit(word, bit, action, mode);
436 }
437
438 /**
439 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
440 * @word: the word being waited on, a kernel virtual address
441 * @bit: the bit of the word being waited on
442 * @action: the function used to sleep, which may take special actions
443 * @mode: the task state to sleep in
444 *
445 * There is a standard hashed waitqueue table for generic use. This
446 * is the part of the hashtable's accessor API that waits on a bit
447 * when one intends to set it, for instance, trying to lock bitflags.
448 * For instance, if one were to have waiters trying to set bitflag
449 * and waiting for it to clear before setting it, one would call
450 * wait_on_bit() in threads waiting to be able to set the bit.
451 * One uses wait_on_bit_lock() where one is waiting for the bit to
452 * clear with the intention of setting it, and when done, clearing it.
453 */
454 static inline int wait_on_bit_lock(void *word, int bit,
455 int (*action)(void *), unsigned mode)
456 {
457 if (!test_and_set_bit(bit, word))
458 return 0;
459 return out_of_line_wait_on_bit_lock(word, bit, action, mode);
460 }
461
462 #endif /* __KERNEL__ */
463
464 #endif
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