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	

#define __WNOTHREAD	0x20000000	
#define __WALL		0x40000000	
#define __WCLONE	0x80000000	

#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/current.h>

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


#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, const char *name, struct lock_class_key *);

#define init_waitqueue_head(q)				\
	do {						\
		static struct lock_class_key __key;	\
							\
		__init_waitqueue_head((q), #q, &__key);	\
	} while (0)

#ifdef CONFIG_LOCKDEP
# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
	({ init_waitqueue_head(&name); name; })
# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
	wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
#else
# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
#endif

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);
}

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

static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
					      wait_queue_t *wait)
{
	wait->flags |= WQ_FLAG_EXCLUSIVE;
	__add_wait_queue(q, wait);
}

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 __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
					      wait_queue_t *wait)
{
	wait->flags |= WQ_FLAG_EXCLUSIVE;
	__add_wait_queue_tail(q, wait);
}

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

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

#define wake_up(x)			__wake_up(x, TASK_NORMAL, 1, NULL)
#define wake_up_nr(x, nr)		__wake_up(x, TASK_NORMAL, nr, NULL)
#define wake_up_all(x)			__wake_up(x, TASK_NORMAL, 0, NULL)
#define wake_up_locked(x)		__wake_up_locked((x), TASK_NORMAL, 1)
#define wake_up_all_locked(x)		__wake_up_locked((x), TASK_NORMAL, 0)

#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_interruptible_sync(x)	__wake_up_sync((x), TASK_INTERRUPTIBLE, 1)

#define wake_up_poll(x, m)				\
	__wake_up(x, TASK_NORMAL, 1, (void *) (m))
#define wake_up_locked_poll(x, m)				\
	__wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
#define wake_up_interruptible_poll(x, m)			\
	__wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
#define wake_up_interruptible_sync_poll(x, m)				\
	__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))

#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)

#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)

#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)

#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)

#define wait_event_interruptible_timeout(wq, condition, timeout)	\
({									\
	long __ret = timeout;						\
	if (!(condition))						\
		__wait_event_interruptible_timeout(wq, condition, __ret); \
	__ret;								\
})

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

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

#define __wait_io_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 = io_schedule_timeout(ret);			\
			if (!ret)					\
				break;					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)


#define wait_io_event_interruptible_timeout(wq, condition, timeout)	\
({									\
	long __ret = timeout;						\
	if (!(condition))						\
		__wait_io_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) {					\
			finish_wait(&wq, &__wait);			\
			break;						\
		}							\
		if (!signal_pending(current)) {				\
			schedule();					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		abort_exclusive_wait(&wq, &__wait, 			\
				TASK_INTERRUPTIBLE, NULL);		\
		break;							\
	}								\
} while (0)

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


#define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
({									\
	int __ret = 0;							\
	DEFINE_WAIT(__wait);						\
	if (exclusive)							\
		__wait.flags |= WQ_FLAG_EXCLUSIVE;			\
	do {								\
		if (likely(list_empty(&__wait.task_list)))		\
			__add_wait_queue_tail(&(wq), &__wait);		\
		set_current_state(TASK_INTERRUPTIBLE);			\
		if (signal_pending(current)) {				\
			__ret = -ERESTARTSYS;				\
			break;						\
		}							\
		if (irq)						\
			spin_unlock_irq(&(wq).lock);			\
		else							\
			spin_unlock(&(wq).lock);			\
		schedule();						\
		if (irq)						\
			spin_lock_irq(&(wq).lock);			\
		else							\
			spin_lock(&(wq).lock);				\
	} while (!(condition));						\
	__remove_wait_queue(&(wq), &__wait);				\
	__set_current_state(TASK_RUNNING);				\
	__ret;								\
})


#define wait_event_interruptible_locked(wq, condition)			\
	((condition)							\
	 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))

#define wait_event_interruptible_locked_irq(wq, condition)		\
	((condition)							\
	 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1))

#define wait_event_interruptible_exclusive_locked(wq, condition)	\
	((condition)							\
	 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0))

#define wait_event_interruptible_exclusive_locked_irq(wq, condition)	\
	((condition)							\
	 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))



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

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

extern void sleep_on(wait_queue_head_t *q);
extern long sleep_on_timeout(wait_queue_head_t *q,
				      signed long timeout);
extern void interruptible_sleep_on(wait_queue_head_t *q);
extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
					   signed long timeout);

void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
			unsigned int mode, void *key);
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_FUNC(name, function)				\
	wait_queue_t name = {						\
		.private	= current,				\
		.func		= function,				\
		.task_list	= LIST_HEAD_INIT((name).task_list),	\
	}

#define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)

#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);			\
		(wait)->flags = 0;					\
	} while (0)

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);
}

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 

#endif