[PATCH] fix remaining missing includes
[linux-2.6.git] / include / linux / wait.h
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
36         void *private;
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
57 struct task_struct;
58
59 /*
60  * Macros for declaration and initialisaton of the datatypes
61  */
62
63 #define __WAITQUEUE_INITIALIZER(name, tsk) {                            \
64         .private        = tsk,                                          \
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;
90         q->private = p;
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;
98         q->private = NULL;
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  */
114 #define is_sync_wait(wait)      (!(wait) || ((wait)->private))
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 = {                                           \
388                 .private        = current,                              \
389                 .func           = autoremove_wake_function,             \
390                 .task_list      = LIST_HEAD_INIT((name).task_list),     \
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   = {                                             \
397                         .private        = current,                      \
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 {                                                            \
406                 (wait)->private = current;                              \
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