/*-
 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * © Portions copyright (c) 2007 Symbian Software Ltd. All rights reserved.
 * $FreeBSD: src/sys/sys/event.h,v 1.32 2005/07/01 16:28:32 ssouhlal Exp $
 */

#ifndef _SYS_EVENT_H_
#define _SYS_EVENT_H_

#define EVFILT_READ		(-1)
#define EVFILT_WRITE		(-2)
#define EVFILT_AIO		(-3)	/* attached to aio requests */
#define EVFILT_VNODE		(-4)	/* attached to vnodes */
#define EVFILT_PROC		(-5)	/* attached to struct proc */
#define EVFILT_SIGNAL		(-6)	/* attached to struct proc */
#define EVFILT_TIMER		(-7)	/* timers */
#define EVFILT_NETDEV		(-8)	/* network devices */
#define EVFILT_FS		(-9)	/* filesystem events */

#define EVFILT_SYSCOUNT		9

#define EV_SET(kevp_, a, b, c, d, e, f) do {	\
	struct kevent *kevp = (kevp_);		\
	(kevp)->ident = (a);			\
	(kevp)->filter = (b);			\
	(kevp)->flags = (c);			\
	(kevp)->fflags = (d);			\
	(kevp)->data = (e);			\
	(kevp)->udata = (f);			\
} while(0)

struct kevent {
	uintptr_t	ident;		/* identifier for this event */
	short		filter;		/* filter for event */
	u_short		flags;
	u_int		fflags;
	intptr_t	data;
	void		*udata;		/* opaque user data identifier */
};

/* actions */
#define EV_ADD		0x0001		/* add event to kq (implies enable) */
#define EV_DELETE	0x0002		/* delete event from kq */
#define EV_ENABLE	0x0004		/* enable event */
#define EV_DISABLE	0x0008		/* disable event (not reported) */

/* flags */
#define EV_ONESHOT	0x0010		/* only report one occurrence */
#define EV_CLEAR	0x0020		/* clear event state after reporting */

#define EV_SYSFLAGS	0xF000		/* reserved by system */
#define EV_FLAG1	0x2000		/* filter-specific flag */

/* returned values */
#define EV_EOF		0x8000		/* EOF detected */
#define EV_ERROR	0x4000		/* error, data contains errno */

/*
 * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
 */
#define NOTE_LOWAT	0x0001			/* low water mark */

/*
 * data/hint flags for EVFILT_VNODE, shared with userspace
 */
#define	NOTE_DELETE	0x0001			/* vnode was removed */
#define	NOTE_WRITE	0x0002			/* data contents changed */
#define	NOTE_EXTEND	0x0004			/* size increased */
#define	NOTE_ATTRIB	0x0008			/* attributes changed */
#define	NOTE_LINK	0x0010			/* link count changed */
#define	NOTE_RENAME	0x0020			/* vnode was renamed */
#define	NOTE_REVOKE	0x0040			/* vnode access was revoked */

/*
 * data/hint flags for EVFILT_PROC, shared with userspace
 */
#define	NOTE_EXIT	0x80000000		/* process exited */
#define	NOTE_FORK	0x40000000		/* process forked */
#define	NOTE_EXEC	0x20000000		/* process exec'd */
#define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
#define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */

/* additional flags for EVFILT_PROC */
#define	NOTE_TRACK	0x00000001		/* follow across forks */
#define	NOTE_TRACKERR	0x00000002		/* could not track child */
#define	NOTE_CHILD	0x00000004		/* am a child process */

/*
 * data/hint flags for EVFILT_NETDEV, shared with userspace
 */
#define NOTE_LINKUP	0x0001			/* link is up */
#define NOTE_LINKDOWN	0x0002			/* link is down */
#define NOTE_LINKINV	0x0004			/* link state is invalid */

/*
 * This is currently visible to userland to work around broken
 * programs which pull in <sys/proc.h>.
 */
#include <sys/queue.h> 
#include <sys/_lock.h>
#include <sys/_mutex.h>
struct knote;
struct kqueue;
struct knlist {
	struct	klist	kl_list;
	void    (*kl_lock)(void *);	/* lock function */
	void    (*kl_unlock)(void *);
	int    (*kl_locked)(void *);
	void *kl_lockarg;		/* argument passed to kl_lockf() */
};


#ifdef _KERNEL

#define	KNLIST_EMPTY(list)		SLIST_EMPTY(&(list)->kl_list)

/*
 * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
 * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
 */
#define NOTE_SIGNAL	0x08000000

struct filterops {
	int	f_isfd;		/* true if ident == filedescriptor */
	int	(*f_attach)(struct knote *kn);
	void	(*f_detach)(struct knote *kn);
	int	(*f_event)(struct knote *kn, long hint);
};

/*
 * Setting the KN_INFLUX flag enables you to unlock the kq that this knote
 * is on, and modify kn_status as if you had the KQ lock.
 *
 * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
 */
struct knote {
	SLIST_ENTRY(knote)	kn_link;	/* for kq */
	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
	struct			knlist *kn_knlist;	/* f_attach populated */
	TAILQ_ENTRY(knote)	kn_tqe;
	struct			kqueue *kn_kq;	/* which queue we are on */
	struct 			kevent kn_kevent;
	int			kn_status;	/* protected by kq lock */
#define KN_ACTIVE	0x01			/* event has been triggered */
#define KN_QUEUED	0x02			/* event is on queue */
#define KN_DISABLED	0x04			/* event is disabled */
#define KN_DETACHED	0x08			/* knote is detached */
#define KN_INFLUX	0x10			/* knote is in flux */
#define KN_MARKER	0x20			/* ignore this knote */
#define KN_KQUEUE	0x40			/* this knote belongs to a kq */
#define KN_HASKQLOCK	0x80			/* for _inevent */
	int			kn_sfflags;	/* saved filter flags */
	intptr_t		kn_sdata;	/* saved data field */
	union {
		struct		file *p_fp;	/* file data pointer */
		struct		proc *p_proc;	/* proc pointer */
	} kn_ptr;
	struct			filterops *kn_fop;
	void			*kn_hook;

#define kn_id		kn_kevent.ident
#define kn_filter	kn_kevent.filter
#define kn_flags	kn_kevent.flags
#define kn_fflags	kn_kevent.fflags
#define kn_data		kn_kevent.data
#define kn_fp		kn_ptr.p_fp
};
struct kevent_copyops {
	void	*arg;
	int	(*k_copyout)(void *arg, struct kevent *kevp, int count);
	int	(*k_copyin)(void *arg, struct kevent *kevp, int count);
};

struct thread;
struct proc;
struct knlist;

#endif /* !_KERNEL */

#endif /* !_SYS_EVENT_H_ */
