[linux.git] / include / linux / wait.h

#ifndef _LINUX_WAIT_H
#define _LINUX_WAIT_H

#define WNOHANG		0x00000001
#define WUNTRACED	0x00000002
#define WSTOPPED	WUNTRACED
#define WEXITED		0x00000004
#define WCONTINUED	0x00000008
#define WNOWAIT		0x01000000	/* Don't reap, just poll status.  */

#define __WNOTHREAD	0x20000000	/* Don't wait on children of other threads in this group */
#define __WALL		0x40000000	/* Wait on all children, regardless of type */
#define __WCLONE	0x80000000	/* Wait only on non-SIGCHLD children */

/* First argument to waitid: */
#define P_ALL		0
#define P_PID		1
#define P_PGID		2

#ifdef __KERNEL__

#include <linux/list.h>
#include <linux/stddef.h>
#include <linux/spinlock.h>
#include <asm/system.h>
#include <asm/current.h>

typedef struct __wait_queue wait_queue_t;
typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key);
int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);

struct __wait_queue {
	unsigned int flags;
#define WQ_FLAG_EXCLUSIVE	0x01
	void *private;
	wait_queue_func_t func;
	struct list_head task_list;
};

struct wait_bit_key {
	void *flags;
	int bit_nr;
};

struct wait_bit_queue {
	struct wait_bit_key key;
	wait_queue_t wait;
};

struct __wait_queue_head {
	spinlock_t lock;
	struct list_head task_list;
};
typedef struct __wait_queue_head wait_queue_head_t;

struct task_struct;

/*
 * Macros for declaration and initialisaton of the datatypes
 */

#define __WAITQUEUE_INITIALIZER(name, tsk) {				\
	.private	= tsk,						\
	.func		= default_wake_function,			\
	.task_list	= { NULL, NULL } }

#define DECLARE_WAITQUEUE(name, tsk)					\
	wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)

#define __WAIT_QUEUE_HEAD_INITIALIZER(name) {				\
	.lock		= __SPIN_LOCK_UNLOCKED(name.lock),		\
	.task_list	= { &(name).task_list, &(name).task_list } }

#define DECLARE_WAIT_QUEUE_HEAD(name) \
	wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)

#define __WAIT_BIT_KEY_INITIALIZER(word, bit)				\
	{ .flags = word, .bit_nr = bit, }

extern void init_waitqueue_head(wait_queue_head_t *q);

static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
{
	q->flags = 0;
	q->private = p;
	q->func = default_wake_function;
}

static inline void init_waitqueue_func_entry(wait_queue_t *q,
					wait_queue_func_t func)
{
	q->flags = 0;
	q->private = NULL;
	q->func = func;
}

static inline int waitqueue_active(wait_queue_head_t *q)
{
	return !list_empty(&q->task_list);
}

/*
 * Used to distinguish between sync and async io wait context:
 * sync i/o typically specifies a NULL wait queue entry or a wait
 * queue entry bound to a task (current task) to wake up.
 * aio specifies a wait queue entry with an async notification
 * callback routine, not associated with any task.
 */
#define is_sync_wait(wait)	(!(wait) || ((wait)->private))

extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));

static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
{
	list_add(&new->task_list, &head->task_list);
}

/*
 * Used for wake-one threads:
 */
static inline void __add_wait_queue_tail(wait_queue_head_t *head,
						wait_queue_t *new)
{
	list_add_tail(&new->task_list, &head->task_list);
}

static inline void __remove_wait_queue(wait_queue_head_t *head,
							wait_queue_t *old)
{
	list_del(&old->task_list);
}

void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key));
extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int));
int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
void FASTCALL(wake_up_bit(void *, int));
int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int));

#define wake_up(x)			__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL)
#define wake_up_nr(x, nr)		__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL)
#define wake_up_all(x)			__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL)
#define wake_up_interruptible(x)	__wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
#define wake_up_interruptible_nr(x, nr)	__wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
#define wake_up_interruptible_all(x)	__wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
#define	wake_up_locked(x)		__wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE)
#define wake_up_interruptible_sync(x)   __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)

#define __wait_event(wq, condition) 					\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		schedule();						\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event - sleep until a condition gets true
 * @wq: the waitqueue to wait on
 * @condition: a C expression for the event to wait for
 *
 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 * @condition evaluates to true. The @condition is checked each time
 * the waitqueue @wq is woken up.
 *
 * wake_up() has to be called after changing any variable that could
 * change the result of the wait condition.
 */
#define wait_event(wq, condition) 					\
do {									\
	if (condition)	 						\
		break;							\
	__wait_event(wq, condition);					\
} while (0)

#define __wait_event_timeout(wq, condition, ret)			\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		ret = schedule_timeout(ret);				\
		if (!ret)						\
			break;						\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
 * @wq: the waitqueue to wait on
 * @condition: a C expression for the event to wait for
 * @timeout: timeout, in jiffies
 *
 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 * @condition evaluates to true. The @condition is checked each time
 * the waitqueue @wq is woken up.
 *
 * wake_up() has to be called after changing any variable that could
 * change the result of the wait condition.
 *
 * The function returns 0 if the @timeout elapsed, and the remaining
 * jiffies if the condition evaluated to true before the timeout elapsed.
 */
#define wait_event_timeout(wq, condition, timeout)			\
({									\
	long __ret = timeout;						\
	if (!(condition)) 						\
		__wait_event_timeout(wq, condition, __ret);		\
	__ret;								\
})

#define __wait_event_interruptible(wq, condition, ret)			\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			schedule();					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event_interruptible - sleep until a condition gets true
 * @wq: the waitqueue to wait on
 * @condition: a C expression for the event to wait for
 *
 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 * @condition evaluates to true or a signal is received.
 * The @condition is checked each time the waitqueue @wq is woken up.
 *
 * wake_up() has to be called after changing any variable that could
 * change the result of the wait condition.
 *
 * The function will return -ERESTARTSYS if it was interrupted by a
 * signal and 0 if @condition evaluated to true.
 */
#define wait_event_interruptible(wq, condition)				\
({									\
	int __ret = 0;							\
	if (!(condition))						\
		__wait_event_interruptible(wq, condition, __ret);	\
	__ret;								\
})

#define __wait_event_interruptible_timeout(wq, condition, ret)		\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			ret = schedule_timeout(ret);			\
			if (!ret)					\
				break;					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
 * @wq: the waitqueue to wait on
 * @condition: a C expression for the event to wait for
 * @timeout: timeout, in jiffies
 *
 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 * @condition evaluates to true or a signal is received.
 * The @condition is checked each time the waitqueue @wq is woken up.
 *
 * wake_up() has to be called after changing any variable that could
 * change the result of the wait condition.
 *
 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
 * was interrupted by a signal, and the remaining jiffies otherwise
 * if the condition evaluated to true before the timeout elapsed.
 */
#define wait_event_interruptible_timeout(wq, condition, timeout)	\
({									\
	long __ret = timeout;						\
	if (!(condition))						\
		__wait_event_interruptible_timeout(wq, condition, __ret); \
	__ret;								\
})

#define __wait_event_interruptible_exclusive(wq, condition, ret)	\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait_exclusive(&wq, &__wait,			\
					TASK_INTERRUPTIBLE);		\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			schedule();					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

#define wait_event_interruptible_exclusive(wq, condition)		\
({									\
	int __ret = 0;							\
	if (!(condition))						\
		__wait_event_interruptible_exclusive(wq, condition, __ret);\
	__ret;								\
})

/*
 * Must be called with the spinlock in the wait_queue_head_t held.
 */
static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
						   wait_queue_t * wait)
{
	wait->flags |= WQ_FLAG_EXCLUSIVE;
	__add_wait_queue_tail(q,  wait);
}

/*
 * Must be called with the spinlock in the wait_queue_head_t held.
 */
static inline void remove_wait_queue_locked(wait_queue_head_t *q,
					    wait_queue_t * wait)
{
	__remove_wait_queue(q,  wait);
}

/*
 * These are the old interfaces to sleep waiting for an event.
 * They are racy.  DO NOT use them, use the wait_event* interfaces above.  
 * We plan to remove these interfaces during 2.7.
 */
extern void FASTCALL(sleep_on(wait_queue_head_t *q));
extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
				      signed long timeout));
extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q,
						    signed long timeout));

/*
 * Waitqueues which are removed from the waitqueue_head at wakeup time
 */
void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
				wait_queue_t *wait, int state));
void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
				wait_queue_t *wait, int state));
void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);

#define DEFINE_WAIT(name)						\
	wait_queue_t name = {						\
		.private	= current,				\
		.func		= autoremove_wake_function,		\
		.task_list	= LIST_HEAD_INIT((name).task_list),	\
	}

#define DEFINE_WAIT_BIT(name, word, bit)				\
	struct wait_bit_queue name = {					\
		.key = __WAIT_BIT_KEY_INITIALIZER(word, bit),		\
		.wait	= {						\
			.private	= current,			\
			.func		= wake_bit_function,		\
			.task_list	=				\
				LIST_HEAD_INIT((name).wait.task_list),	\
		},							\
	}

#define init_wait(wait)							\
	do {								\
		(wait)->private = current;				\
		(wait)->func = autoremove_wake_function;		\
		INIT_LIST_HEAD(&(wait)->task_list);			\
	} while (0)

/**
 * wait_on_bit - wait for a bit to be cleared
 * @word: the word being waited on, a kernel virtual address
 * @bit: the bit of the word being waited on
 * @action: the function used to sleep, which may take special actions
 * @mode: the task state to sleep in
 *
 * There is a standard hashed waitqueue table for generic use. This
 * is the part of the hashtable's accessor API that waits on a bit.
 * For instance, if one were to have waiters on a bitflag, one would
 * call wait_on_bit() in threads waiting for the bit to clear.
 * One uses wait_on_bit() where one is waiting for the bit to clear,
 * but has no intention of setting it.
 */
static inline int wait_on_bit(void *word, int bit,
				int (*action)(void *), unsigned mode)
{
	if (!test_bit(bit, word))
		return 0;
	return out_of_line_wait_on_bit(word, bit, action, mode);
}

/**
 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
 * @word: the word being waited on, a kernel virtual address
 * @bit: the bit of the word being waited on
 * @action: the function used to sleep, which may take special actions
 * @mode: the task state to sleep in
 *
 * There is a standard hashed waitqueue table for generic use. This
 * is the part of the hashtable's accessor API that waits on a bit
 * when one intends to set it, for instance, trying to lock bitflags.
 * For instance, if one were to have waiters trying to set bitflag
 * and waiting for it to clear before setting it, one would call
 * wait_on_bit() in threads waiting to be able to set the bit.
 * One uses wait_on_bit_lock() where one is waiting for the bit to
 * clear with the intention of setting it, and when done, clearing it.
 */
static inline int wait_on_bit_lock(void *word, int bit,
				int (*action)(void *), unsigned mode)
{
	if (!test_and_set_bit(bit, word))
		return 0;
	return out_of_line_wait_on_bit_lock(word, bit, action, mode);
}
	
#endif /* __KERNEL__ */

#endif
Commit	Line	Data
1da177e4 LT	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
1da177e4 LT	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
c43dc2fd	35	void *private;
1da177e4 LT	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
8c65b4a6	56	struct task_struct;
1da177e4 LT	57
	58	/*
	59	* Macros for declaration and initialisaton of the datatypes
	60	*/
	61
	62	#define __WAITQUEUE_INITIALIZER(name, tsk) { \
c43dc2fd	63	.private = tsk, \
1da177e4 LT	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) { \
e4d91918	71	.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
1da177e4 LT	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
21d71f51	80	extern void init_waitqueue_head(wait_queue_head_t *q);
1da177e4 LT	81
	82	static inline void init_waitqueue_entry(wait_queue_t q, struct task_struct p)
	83	{
	84	q->flags = 0;
c43dc2fd	85	q->private = p;
1da177e4 LT	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;
c43dc2fd	93	q->private = NULL;
1da177e4 LT	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	*/
c43dc2fd	109	#define is_sync_wait(wait) (!(wait) \|\| ((wait)->private))
1da177e4 LT	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 = { \
c43dc2fd	383	.private = current, \
1da177e4	384	.func = autoremove_wake_function, \
7e43c84e	385	.task_list = LIST_HEAD_INIT((name).task_list), \
1da177e4 LT	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 = { \
c43dc2fd	392	.private = current, \
1da177e4 LT	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 { \
c43dc2fd	401	(wait)->private = current; \
1da177e4 LT	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