1 /*-
2  * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  *	$FreeBSD: src/sys/sys/event.h,v 1.19 2002/03/23 08:46:51 bde Exp $
27  */
28 
29 #ifndef _SYS_EVENT_H_
30 #define _SYS_EVENT_H_
31 
32 #define EVFILT_READ		(-1)
33 #define EVFILT_WRITE		(-2)
34 #define EVFILT_AIO		(-3)	/* attached to aio requests */
35 #define EVFILT_VNODE		(-4)	/* attached to vnodes */
36 #define EVFILT_PROC		(-5)	/* attached to struct proc */
37 #define EVFILT_SIGNAL		(-6)	/* attached to struct proc */
38 #define EVFILT_TIMER		(-7)	/* timers */
39 #define EVFILT_NETDEV		(-8)	/* network devices */
40 
41 #define EVFILT_SYSCOUNT		8
42 
43 #define EV_SET(kevp, a, b, c, d, e, f) do {	\
44 	(kevp)->ident = (a);			\
45 	(kevp)->filter = (b);			\
46 	(kevp)->flags = (c);			\
47 	(kevp)->fflags = (d);			\
48 	(kevp)->data = (e);			\
49 	(kevp)->udata = (f);			\
50 } while(0)
51 
52 struct kevent {
53 	unsigned int *	ident;		/* identifier for this event */
54 	short		filter;		/* filter for event */
55 	u_short		flags;
56 	u_int		fflags;
57         int * 	        data;
58 	void		*udata;		/* opaque user data identifier */
59 };
60 
61 /* actions */
62 #define EV_ADD		0x0001		/* add event to kq (implies enable) */
63 #define EV_DELETE	0x0002		/* delete event from kq */
64 #define EV_ENABLE	0x0004		/* enable event */
65 #define EV_DISABLE	0x0008		/* disable event (not reported) */
66 
67 /* flags */
68 #define EV_ONESHOT	0x0010		/* only report one occurrence */
69 #define EV_CLEAR	0x0020		/* clear event state after reporting */
70 
71 #define EV_SYSFLAGS	0xF000		/* reserved by system */
72 #define EV_FLAG1	0x2000		/* filter-specific flag */
73 
74 /* returned values */
75 #define EV_EOF		0x8000		/* EOF detected */
76 #define EV_ERROR	0x4000		/* error, data contains errno */
77 
78 /*
79  * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
80  */
81 #define NOTE_LOWAT	0x0001			/* low water mark */
82 
83 /*
84  * data/hint flags for EVFILT_VNODE, shared with userspace
85  */
86 #define	NOTE_DELETE	0x0001			/* vnode was removed */
87 #define	NOTE_WRITE	0x0002			/* data contents changed */
88 #define	NOTE_EXTEND	0x0004			/* size increased */
89 #define	NOTE_ATTRIB	0x0008			/* attributes changed */
90 #define	NOTE_LINK	0x0010			/* link count changed */
91 #define	NOTE_RENAME	0x0020			/* vnode was renamed */
92 #define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
93 
94 /*
95  * data/hint flags for EVFILT_PROC, shared with userspace
96  */
97 #define	NOTE_EXIT	0x80000000		/* process exited */
98 #define	NOTE_FORK	0x40000000		/* process forked */
99 #define	NOTE_EXEC	0x20000000		/* process exec'd */
100 #define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
101 #define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
102 
103 /* additional flags for EVFILT_PROC */
104 #define	NOTE_TRACK	0x00000001		/* follow across forks */
105 #define	NOTE_TRACKERR	0x00000002		/* could not track child */
106 #define	NOTE_CHILD	0x00000004		/* am a child process */
107 
108 /*
109  * data/hint flags for EVFILT_NETDEV, shared with userspace
110  */
111 #define NOTE_LINKUP	0x0001			/* link is up */
112 #define NOTE_LINKDOWN	0x0002			/* link is down */
113 #define NOTE_LINKINV	0x0004			/* link state is invalid */
114 
115 /*
116  * This is currently visible to userland to work around broken
117  * programs which pull in <sys/proc.h> or <sys/select.h>.
118  */
119 #include <sys/queue.h>
120 struct knote;
121 
122 #ifdef _KERNEL
123 
124 #ifdef MALLOC_DECLARE
125 MALLOC_DECLARE(M_KQUEUE);
126 #endif
127 
128 #define KNOTE(list, hint)	if ((list) != NULL) knote(list, hint)
129 
130 /*
131  * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
132  * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
133  */
134 #define NOTE_SIGNAL	0x08000000
135 
136 struct filterops {
137 	int	f_isfd;		/* true if ident == filedescriptor */
138 	int	(*f_attach)(struct knote *kn);
139 	void	(*f_detach)(struct knote *kn);
140 	int	(*f_event)(struct knote *kn, long hint);
141 };
142 
143 struct knote {
144 	SLIST_ENTRY(knote)	kn_link;	/* for fd */
145 	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
146 	TAILQ_ENTRY(knote)	kn_tqe;
147 	struct			kqueue *kn_kq;	/* which queue we are on */
148 	struct 			kevent kn_kevent;
149 	int			kn_status;
150 	int			kn_sfflags;	/* saved filter flags */
151 	intptr_t		kn_sdata;	/* saved data field */
152 	union {
153 		struct		file *p_fp;	/* file data pointer */
154 		struct		proc *p_proc;	/* proc pointer */
155 	} kn_ptr;
156 	struct			filterops *kn_fop;
157 	caddr_t			kn_hook;
158 #define KN_ACTIVE	0x01			/* event has been triggered */
159 #define KN_QUEUED	0x02			/* event is on queue */
160 #define KN_DISABLED	0x04			/* event is disabled */
161 #define KN_DETACHED	0x08			/* knote is detached */
162 
163 #define kn_id		kn_kevent.ident
164 #define kn_filter	kn_kevent.filter
165 #define kn_flags	kn_kevent.flags
166 #define kn_fflags	kn_kevent.fflags
167 #define kn_data		kn_kevent.data
168 #define kn_fp		kn_ptr.p_fp
169 };
170 
171 struct thread;
172 struct proc;
173 
174 extern void	knote(struct klist *list, long hint);
175 extern void	knote_remove(struct thread *p, struct klist *list);
176 extern void	knote_fdclose(struct thread *p, int fd);
177 extern int 	kqueue_register(struct kqueue *kq,
178 		    struct kevent *kev, struct thread *p);
179 extern int	kqueue_add_filteropts(int filt, struct filterops *filtops);
180 extern int	kqueue_del_filteropts(int filt);
181 
182 #else 	/* !_KERNEL */
183 
184 #include <sys/cdefs.h>
185 struct timespec;
186 
187 __BEGIN_DECLS
188 int     kqueue(void);
189 int     kevent(int kq, const struct kevent *changelist, int nchanges,
190 	    struct kevent *eventlist, int nevents,
191 	    const struct timespec *timeout);
192 __END_DECLS
193 
194 #endif /* !_KERNEL */
195 
196 #endif /* !_SYS_EVENT_H_ */
197