event.h revision 1.25 
1/*	$NetBSD: event.h,v 1.25 2015/12/08 14:52:06 christos 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		0U
40#define	EVFILT_WRITE		1U
41#define	EVFILT_AIO		2U	/* attached to aio requests */
42#define	EVFILT_VNODE		3U	/* attached to vnodes */
43#define	EVFILT_PROC		4U	/* attached to struct proc */
44#define	EVFILT_SIGNAL		5U	/* attached to struct proc */
45#define	EVFILT_TIMER		6U	/* arbitrary timer (in ms) */
46#define	EVFILT_SYSCOUNT		7U	/* number of filters */
47
48#define	EV_SET(kevp, a, b, c, d, e, f)					\
49do {									\
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
59struct 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		0x0001U		/* add event to kq (implies ENABLE) */
70#define	EV_DELETE	0x0002U		/* delete event from kq */
71#define	EV_ENABLE	0x0004U		/* enable event */
72#define	EV_DISABLE	0x0008U		/* disable event (not reported) */
73
74/* flags */
75#define	EV_ONESHOT	0x0010U		/* only report one occurrence */
76#define	EV_CLEAR	0x0020U		/* clear event state after reporting */
77#define EV_RECEIPT	0x0040U		/* force EV_ERROR on success, data=0 */
78#define EV_DISPATCH	0x0080U		/* disable event after reporting */
79
80#define	EV_SYSFLAGS	0xF000U		/* reserved by system */
81#define	EV_FLAG1	0x2000U		/* filter-specific flag */
82
83/* returned values */
84#define	EV_EOF		0x8000U		/* EOF detected */
85#define	EV_ERROR	0x4000U		/* error, data contains errno */
86
87/*
88 * hint flag for in-kernel use - must not equal any existing note
89 */
90#ifdef _KERNEL
91#define NOTE_SUBMIT	0x01000000U		/* initial knote submission */
92#endif
93/*
94 * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
95 */
96#define	NOTE_LOWAT	0x0001U			/* low water mark */
97
98/*
99 * data/hint flags for EVFILT_VNODE, shared with userspace
100 */
101#define	NOTE_DELETE	0x0001U			/* vnode was removed */
102#define	NOTE_WRITE	0x0002U			/* data contents changed */
103#define	NOTE_EXTEND	0x0004U			/* size increased */
104#define	NOTE_ATTRIB	0x0008U			/* attributes changed */
105#define	NOTE_LINK	0x0010U			/* link count changed */
106#define	NOTE_RENAME	0x0020U			/* vnode was renamed */
107#define	NOTE_REVOKE	0x0040U			/* vnode access was revoked */
108
109/*
110 * data/hint flags for EVFILT_PROC, shared with userspace
111 */
112#define	NOTE_EXIT	0x80000000U		/* process exited */
113#define	NOTE_FORK	0x40000000U		/* process forked */
114#define	NOTE_EXEC	0x20000000U		/* process exec'd */
115#define	NOTE_PCTRLMASK	0xf0000000U		/* mask for hint bits */
116#define	NOTE_PDATAMASK	0x000fffffU		/* mask for pid */
117
118/* additional flags for EVFILT_PROC */
119#define	NOTE_TRACK	0x00000001U		/* follow across forks */
120#define	NOTE_TRACKERR	0x00000002U		/* could not track child */
121#define	NOTE_CHILD	0x00000004U		/* am a child process */
122
123/*
124 * This is currently visible to userland to work around broken
125 * programs which pull in <sys/proc.h> or <sys/select.h>.
126 */
127#include <sys/queue.h>
128struct knote;
129SLIST_HEAD(klist, knote);
130
131
132/*
133 * ioctl(2)s supported on kqueue descriptors.
134 */
135#include <sys/ioctl.h>
136
137struct kfilter_mapping {
138	char		*name;		/* name to lookup or return */
139	size_t		len;		/* length of name */
140	uint32_t	filter;		/* filter to lookup or return */
141};
142
143/* map filter to name (max size len) */
144#define KFILTER_BYFILTER	_IOWR('k', 0, struct kfilter_mapping)
145/* map name to filter (len ignored) */
146#define KFILTER_BYNAME		_IOWR('k', 1, struct kfilter_mapping)
147
148#ifdef _KERNEL
149
150#define	KNOTE(list, hint)	if (!SLIST_EMPTY(list)) knote(list, hint)
151
152/*
153 * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
154 * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
155 */
156#define	NOTE_SIGNAL	0x08000000U
157
158/*
159 * Callback methods for each filter type.
160 */
161struct filterops {
162	int	f_isfd;			/* true if ident == filedescriptor */
163	int	(*f_attach)	(struct knote *);
164					/* called when knote is ADDed */
165	void	(*f_detach)	(struct knote *);
166					/* called when knote is DELETEd */
167	int	(*f_event)	(struct knote *, long);
168					/* called when event is triggered */
169};
170
171/*
172 * Field locking:
173 *
174 * f	kn_kq->kq_fdp->fd_lock
175 * q	kn_kq->kq_lock
176 * o	object mutex (e.g. device driver or vnode interlock)
177 */
178struct kfilter;
179
180struct knote {
181	SLIST_ENTRY(knote)	kn_link;	/* f: for fd */
182	SLIST_ENTRY(knote)	kn_selnext;	/* o: for struct selinfo */
183	TAILQ_ENTRY(knote)	kn_tqe;		/* q: for struct kqueue */
184	struct kqueue		*kn_kq;		/* q: which queue we are on */
185	struct kevent		kn_kevent;
186	uint32_t		kn_status;
187	uint32_t		kn_sfflags;	/*   saved filter flags */
188	uintptr_t		kn_sdata;	/*   saved data field */
189	void			*kn_obj;	/*   pointer to monitored obj */
190	const struct filterops	*kn_fop;
191	struct kfilter		*kn_kfilter;
192	void 			*kn_hook;
193
194#define	KN_ACTIVE	0x01U			/* event has been triggered */
195#define	KN_QUEUED	0x02U			/* event is on queue */
196#define	KN_DISABLED	0x04U			/* event is disabled */
197#define	KN_DETACHED	0x08U			/* knote is detached */
198#define	KN_MARKER	0x10U			/* is a marker */
199
200#define	kn_id		kn_kevent.ident
201#define	kn_filter	kn_kevent.filter
202#define	kn_flags	kn_kevent.flags
203#define	kn_fflags	kn_kevent.fflags
204#define	kn_data		kn_kevent.data
205};
206
207#include <sys/systm.h> /* for copyin_t */
208
209struct lwp;
210struct timespec;
211
212void	kqueue_init(void);
213void	knote(struct klist *, long);
214void	knote_fdclose(int);
215
216typedef	int (*kevent_fetch_changes_t)(void *, const struct kevent *,
217    struct kevent *, size_t, int);
218typedef	int (*kevent_put_events_t)(void *, struct kevent *, struct kevent *,
219    size_t, int);
220
221struct kevent_ops {
222	void *keo_private;
223	copyin_t keo_fetch_timeout;
224	kevent_fetch_changes_t keo_fetch_changes;
225	kevent_put_events_t keo_put_events;
226};
227
228
229int	kevent_fetch_changes(void *, const struct kevent *, struct kevent *,
230    size_t, int);
231int 	kevent_put_events(void *, struct kevent *, struct kevent *, size_t,
232    int);
233int	kevent1(register_t *, int, const struct kevent *,
234    size_t, struct kevent *, size_t, const struct timespec *,
235    const struct kevent_ops *);
236
237int	kfilter_register(const char *, const struct filterops *, int *);
238int	kfilter_unregister(const char *);
239
240int	filt_seltrue(struct knote *, long);
241extern const struct filterops seltrue_filtops;
242
243#else 	/* !_KERNEL */
244
245#include <sys/cdefs.h>
246struct timespec;
247
248__BEGIN_DECLS
249#if defined(_NETBSD_SOURCE)
250int	kqueue(void);
251int	kqueue1(int);
252#ifndef __LIBC12_SOURCE__
253int	kevent(int, const struct kevent *, size_t, struct kevent *, size_t,
254		    const struct timespec *) __RENAME(__kevent50);
255#endif
256#endif /* !_POSIX_C_SOURCE */
257__END_DECLS
258
259#endif /* !_KERNEL */
260
261#endif /* !_SYS_EVENT_H_ */
262