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