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MOXA linux-2.6.x / linux-2.6.19-uc1 from UC-7110-LX-BOOTLOADER-1.9_VERSION-4.2.tgz
[linux-2.6.19-moxart.git] / include / linux / wait.h
blobe820d00e13836af125710e67753ad5fee2b9bc36
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_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) \
165 do { \
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) \
190 do { \
191 if (condition) \
192 break; \
193 __wait_event(wq, condition); \
194 } while (0)
195
196 #define __wait_event_timeout(wq, condition, ret) \
197 do { \
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) \
236 do { \
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) \
277 do { \
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) \
322 do { \
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 */
351 static 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 */
361 static 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.
369 * They are racy. DO NOT use them, use the wait_event* interfaces above.
370 * We plan to remove these interfaces during 2.7.
371 */
372 extern void FASTCALL(sleep_on(wait_queue_head_t *q));
373 extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
374 signed long timeout));
375 extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
376 extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q,
377 signed long timeout));
378
379 /*
380 * Waitqueues which are removed from the waitqueue_head at wakeup time
381 */
382 void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
383 wait_queue_t *wait, int state));
384 void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
385 wait_queue_t *wait, int state));
386 void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
387 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
388 int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
389
390 #define DEFINE_WAIT(name) \
391 wait_queue_t name = { \
392 .private = current, \
393 .func = autoremove_wake_function, \
394 .task_list = LIST_HEAD_INIT((name).task_list), \
395 }
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 = { \
401 .private = current, \
402 .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 { \
410 (wait)->private = current; \
411 (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 */
429 static 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 */
453 static 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
MOXA 2.6.19 from UC-7110-LX-BOOTLOADER-1.9_VERSION-4.2.tgz