xref: /netbsd-src/sys/sys/event.h (revision f82d7874c259b2a6cc59b714f844919f32bf7b51)
1 /*	$NetBSD: event.h,v 1.20 2008/03/21 21:53:35 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  *	$FreeBSD: src/sys/sys/event.h,v 1.12 2001/02/24 01:44:03 jlemon Exp $
29  */
30 
31 #ifndef _SYS_EVENT_H_
32 #define	_SYS_EVENT_H_
33 
34 #include <sys/featuretest.h>
35 #include <sys/types.h>			/* for size_t */
36 #include <sys/inttypes.h>		/* for uintptr_t */
37 #include <sys/null.h>			/* for NULL */
38 
39 #define	EVFILT_READ		0
40 #define	EVFILT_WRITE		1
41 #define	EVFILT_AIO		2	/* attached to aio requests */
42 #define	EVFILT_VNODE		3	/* attached to vnodes */
43 #define	EVFILT_PROC		4	/* attached to struct proc */
44 #define	EVFILT_SIGNAL		5	/* attached to struct proc */
45 #define	EVFILT_TIMER		6	/* arbitrary timer (in ms) */
46 #define	EVFILT_SYSCOUNT		7	/* number of filters */
47 
48 #define	EV_SET(kevp, a, b, c, d, e, f)					\
49 do {									\
50 	(kevp)->ident = (a);						\
51 	(kevp)->filter = (b);						\
52 	(kevp)->flags = (c);						\
53 	(kevp)->fflags = (d);						\
54 	(kevp)->data = (e);						\
55 	(kevp)->udata = (f);						\
56 } while (/* CONSTCOND */ 0)
57 
58 
59 struct kevent {
60 	uintptr_t	ident;		/* identifier for this event */
61 	uint32_t	filter;		/* filter for event */
62 	uint32_t	flags;		/* action flags for kqueue */
63 	uint32_t	fflags;		/* filter flag value */
64 	int64_t		data;		/* filter data value */
65 	intptr_t	udata;		/* opaque user data identifier */
66 };
67 
68 /* actions */
69 #define	EV_ADD		0x0001		/* add event to kq (implies ENABLE) */
70 #define	EV_DELETE	0x0002		/* delete event from kq */
71 #define	EV_ENABLE	0x0004		/* enable event */
72 #define	EV_DISABLE	0x0008		/* disable event (not reported) */
73 
74 /* flags */
75 #define	EV_ONESHOT	0x0010		/* only report one occurrence */
76 #define	EV_CLEAR	0x0020		/* clear event state after reporting */
77 
78 #define	EV_SYSFLAGS	0xF000		/* reserved by system */
79 #define	EV_FLAG1	0x2000		/* filter-specific flag */
80 
81 /* returned values */
82 #define	EV_EOF		0x8000		/* EOF detected */
83 #define	EV_ERROR	0x4000		/* error, data contains errno */
84 
85 /*
86  * hint flag for in-kernel use - must not equal any existing note
87  */
88 #ifdef _KERNEL
89 #define NOTE_SUBMIT	0x01000000		/* initial knote submission */
90 #endif
91 /*
92  * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
93  */
94 #define	NOTE_LOWAT	0x0001			/* low water mark */
95 
96 /*
97  * data/hint flags for EVFILT_VNODE, shared with userspace
98  */
99 #define	NOTE_DELETE	0x0001			/* vnode was removed */
100 #define	NOTE_WRITE	0x0002			/* data contents changed */
101 #define	NOTE_EXTEND	0x0004			/* size increased */
102 #define	NOTE_ATTRIB	0x0008			/* attributes changed */
103 #define	NOTE_LINK	0x0010			/* link count changed */
104 #define	NOTE_RENAME	0x0020			/* vnode was renamed */
105 #define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
106 
107 /*
108  * data/hint flags for EVFILT_PROC, shared with userspace
109  */
110 #define	NOTE_EXIT	0x80000000		/* process exited */
111 #define	NOTE_FORK	0x40000000		/* process forked */
112 #define	NOTE_EXEC	0x20000000		/* process exec'd */
113 #define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
114 #define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
115 
116 /* additional flags for EVFILT_PROC */
117 #define	NOTE_TRACK	0x00000001		/* follow across forks */
118 #define	NOTE_TRACKERR	0x00000002		/* could not track child */
119 #define	NOTE_CHILD	0x00000004		/* am a child process */
120 
121 /*
122  * This is currently visible to userland to work around broken
123  * programs which pull in <sys/proc.h> or <sys/select.h>.
124  */
125 #include <sys/queue.h>
126 struct knote;
127 SLIST_HEAD(klist, knote);
128 
129 
130 /*
131  * ioctl(2)s supported on kqueue descriptors.
132  */
133 #include <sys/ioctl.h>
134 
135 struct kfilter_mapping {
136 	char		*name;		/* name to lookup or return */
137 	size_t		len;		/* length of name */
138 	uint32_t	filter;		/* filter to lookup or return */
139 };
140 
141 /* map filter to name (max size len) */
142 #define KFILTER_BYFILTER	_IOWR('k', 0, struct kfilter_mapping)
143 /* map name to filter (len ignored) */
144 #define KFILTER_BYNAME		_IOWR('k', 1, struct kfilter_mapping)
145 
146 #ifdef _KERNEL
147 #include <sys/mallocvar.h>		/* for malloc types */
148 
149 MALLOC_DECLARE(M_KEVENT);
150 
151 #define	KNOTE(list, hint)	if (!SLIST_EMPTY(list)) knote(list, hint)
152 
153 /*
154  * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
155  * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
156  */
157 #define	NOTE_SIGNAL	0x08000000
158 
159 /*
160  * Callback methods for each filter type.
161  */
162 struct filterops {
163 	int	f_isfd;			/* true if ident == filedescriptor */
164 	int	(*f_attach)	(struct knote *);
165 					/* called when knote is ADDed */
166 	void	(*f_detach)	(struct knote *);
167 					/* called when knote is DELETEd */
168 	int	(*f_event)	(struct knote *, long);
169 					/* called when event is triggered */
170 };
171 
172 /*
173  * Field locking:
174  *
175  * f	kn_kq->kq_fdp->fd_lock
176  * q	kn_kq->kq_lock
177  * o	object mutex (e.g. device driver or vnode interlock)
178  */
179 struct kfilter;
180 
181 struct knote {
182 	SLIST_ENTRY(knote)	kn_link;	/* f: for fd */
183 	SLIST_ENTRY(knote)	kn_selnext;	/* o: for struct selinfo */
184 	TAILQ_ENTRY(knote)	kn_tqe;		/* q: for struct kqueue */
185 	struct kqueue		*kn_kq;		/* q: which queue we are on */
186 	struct kevent		kn_kevent;
187 	uint32_t		kn_status;
188 	uint32_t		kn_sfflags;	/*   saved filter flags */
189 	uintptr_t		kn_sdata;	/*   saved data field */
190 	void			*kn_obj;	/*   pointer to monitored obj */
191 	const struct filterops	*kn_fop;
192 	struct kfilter		*kn_kfilter;
193 	void 			*kn_hook;
194 
195 #define	KN_ACTIVE	0x01			/* event has been triggered */
196 #define	KN_QUEUED	0x02			/* event is on queue */
197 #define	KN_DISABLED	0x04			/* event is disabled */
198 #define	KN_DETACHED	0x08			/* knote is detached */
199 #define	KN_MARKER	0x10			/* is a marker */
200 
201 #define	kn_id		kn_kevent.ident
202 #define	kn_filter	kn_kevent.filter
203 #define	kn_flags	kn_kevent.flags
204 #define	kn_fflags	kn_kevent.fflags
205 #define	kn_data		kn_kevent.data
206 };
207 
208 #include <sys/systm.h> /* for copyin_t */
209 
210 struct lwp;
211 struct timespec;
212 
213 void	kqueue_init(void);
214 void	knote(struct klist *, long);
215 void	knote_fdclose(int);
216 
217 typedef	int (*kevent_fetch_changes_t)(void *, const struct kevent *,
218     struct kevent *, size_t, int);
219 typedef	int (*kevent_put_events_t)(void *, struct kevent *, struct kevent *,
220     size_t, int);
221 
222 struct kevent_ops {
223 	void *keo_private;
224 	copyin_t keo_fetch_timeout;
225 	kevent_fetch_changes_t keo_fetch_changes;
226 	kevent_put_events_t keo_put_events;
227 };
228 
229 int	kevent1(register_t *, int, const struct kevent *, size_t,
230 		struct kevent *, size_t, const struct timespec *,
231 		const struct kevent_ops *);
232 
233 int	kfilter_register(const char *, const struct filterops *, int *);
234 int	kfilter_unregister(const char *);
235 
236 int	filt_seltrue(struct knote *, long);
237 extern const struct filterops seltrue_filtops;
238 
239 #else 	/* !_KERNEL */
240 
241 #include <sys/cdefs.h>
242 struct timespec;
243 
244 __BEGIN_DECLS
245 #if defined(_NETBSD_SOURCE)
246 int	kqueue(void);
247 int	kevent(int, const struct kevent *, size_t, struct kevent *, size_t,
248 		    const struct timespec *);
249 #endif /* !_POSIX_C_SOURCE */
250 __END_DECLS
251 
252 #endif /* !_KERNEL */
253 
254 #endif /* !_SYS_EVENT_H_ */
255