1/* $NetBSD: event.h,v 1.32 2018/01/09 03:31:13 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_FS 7U /* filesystem events */
47#define EVFILT_SYSCOUNT 8U /* number of filters */
48
49struct kevent {
50 uintptr_t ident; /* identifier for this event */
51 uint32_t filter; /* filter for event */
52 uint32_t flags; /* action flags for kqueue */
53 uint32_t fflags; /* filter flag value */
54 int64_t data; /* filter data value */
55 intptr_t udata; /* opaque user data identifier */
56};
57
58#define EV_SET(kevp, ident, filter, flags, fflags, data, udata) \
59 _EV_SET((kevp), __CAST(uintptr_t, (ident)), (filter), (flags), \
60 (fflags), (data), __CAST(intptr_t, (udata)))
61
62static __inline void
63_EV_SET(struct kevent *_kevp, uintptr_t _ident, uint32_t _filter,
64 uint32_t _flags, uint32_t _fflags, int64_t _data, intptr_t _udata)
65{
66 _kevp->ident = _ident;
67 _kevp->filter = _filter;
68 _kevp->flags = _flags;
69 _kevp->fflags = _fflags;
70 _kevp->data = _data;
71 _kevp->udata = _udata;
72}
73
74/* actions */
75#define EV_ADD 0x0001U /* add event to kq (implies ENABLE) */
76#define EV_DELETE 0x0002U /* delete event from kq */
77#define EV_ENABLE 0x0004U /* enable event */
78#define EV_DISABLE 0x0008U /* disable event (not reported) */
79
80/* flags */
81#define EV_ONESHOT 0x0010U /* only report one occurrence */
82#define EV_CLEAR 0x0020U /* clear event state after reporting */
83#define EV_RECEIPT 0x0040U /* force EV_ERROR on success, data=0 */
84#define EV_DISPATCH 0x0080U /* disable event after reporting */
85
86#define EV_SYSFLAGS 0xF000U /* reserved by system */
87#define EV_FLAG1 0x2000U /* filter-specific flag */
88
89/* returned values */
90#define EV_EOF 0x8000U /* EOF detected */
91#define EV_ERROR 0x4000U /* error, data contains errno */
92
93/*
94 * hint flag for in-kernel use - must not equal any existing note
95 */
96#ifdef _KERNEL
97#define NOTE_SUBMIT 0x01000000U /* initial knote submission */
98#endif
99/*
100 * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
101 */
102#define NOTE_LOWAT 0x0001U /* low water mark */
103
104/*
105 * data/hint flags for EVFILT_VNODE, shared with userspace
106 */
107#define NOTE_DELETE 0x0001U /* vnode was removed */
108#define NOTE_WRITE 0x0002U /* data contents changed */
109#define NOTE_EXTEND 0x0004U /* size increased */
110#define NOTE_ATTRIB 0x0008U /* attributes changed */
111#define NOTE_LINK 0x0010U /* link count changed */
112#define NOTE_RENAME 0x0020U /* vnode was renamed */
113#define NOTE_REVOKE 0x0040U /* vnode access was revoked */
114
115/*
116 * data/hint flags for EVFILT_PROC, shared with userspace
117 */
118#define NOTE_EXIT 0x80000000U /* process exited */
119#define NOTE_FORK 0x40000000U /* process forked */
120#define NOTE_EXEC 0x20000000U /* process exec'd */
121#define NOTE_PCTRLMASK 0xf0000000U /* mask for hint bits */
122#define NOTE_PDATAMASK 0x000fffffU /* mask for pid */
123
124/* additional flags for EVFILT_PROC */
125#define NOTE_TRACK 0x00000001U /* follow across forks */
126#define NOTE_TRACKERR 0x00000002U /* could not track child */
127#define NOTE_CHILD 0x00000004U /* am a child process */
128
129/*
130 * This is currently visible to userland to work around broken
131 * programs which pull in <sys/proc.h> or <sys/select.h>.
132 */
133#include <sys/queue.h>
134struct knote;
135SLIST_HEAD(klist, knote);
136
137
138/*
139 * ioctl(2)s supported on kqueue descriptors.
140 */
141#include <sys/ioctl.h>
142
143struct kfilter_mapping {
144 char *name; /* name to lookup or return */
145 size_t len; /* length of name */
146 uint32_t filter; /* filter to lookup or return */
147};
148
149/* map filter to name (max size len) */
150#define KFILTER_BYFILTER _IOWR('k', 0, struct kfilter_mapping)
151/* map name to filter (len ignored) */
152#define KFILTER_BYNAME _IOWR('k', 1, struct kfilter_mapping)
153
154#ifdef _KERNEL
155
156#define KNOTE(list, hint) if (!SLIST_EMPTY(list)) knote(list, hint)
157
158/*
159 * Flag indicating hint is a signal. Used by EVFILT_SIGNAL, and also
160 * shared by EVFILT_PROC (all knotes attached to p->p_klist)
161 */
162#define NOTE_SIGNAL 0x08000000U
163
164/*
165 * Callback methods for each filter type.
166 */
167struct filterops {
168 int f_isfd; /* true if ident == filedescriptor */
169 int (*f_attach) (struct knote *);
170 /* called when knote is ADDed */
171 void (*f_detach) (struct knote *);
172 /* called when knote is DELETEd */
173 int (*f_event) (struct knote *, long);
174 /* called when event is triggered */
175};
176
177/*
178 * Field locking:
179 *
180 * f kn_kq->kq_fdp->fd_lock
181 * q kn_kq->kq_lock
182 * o object mutex (e.g. device driver or vnode interlock)
183 */
184struct kfilter;
185
186struct knote {
187 SLIST_ENTRY(knote) kn_link; /* f: for fd */
188 SLIST_ENTRY(knote) kn_selnext; /* o: for struct selinfo */
189 TAILQ_ENTRY(knote) kn_tqe; /* q: for struct kqueue */
190 struct kqueue *kn_kq; /* q: which queue we are on */
191 struct kevent kn_kevent;
192 uint32_t kn_status; /* q: flags below */
193 uint32_t kn_sfflags; /* saved filter flags */
194 uintptr_t kn_sdata; /* saved data field */
195 void *kn_obj; /* monitored obj */
196 const struct filterops *kn_fop;
197 struct kfilter *kn_kfilter;
198 void *kn_hook;
199
200#define KN_ACTIVE 0x01U /* event has been triggered */
201#define KN_QUEUED 0x02U /* event is on queue */
202#define KN_DISABLED 0x04U /* event is disabled */
203#define KN_DETACHED 0x08U /* knote is detached */
204#define KN_MARKER 0x10U /* is a marker */
205#define KN_BUSY 0x20U /* is being scanned */
206/* Toggling KN_BUSY also requires kn_kq->kq_fdp->fd_lock. */
207#define __KN_FLAG_BITS \
208 "\20" \
209 "\1ACTIVE" \
210 "\2QUEUED" \
211 "\3DISABLED" \
212 "\4DETACHED" \
213 "\5MARKER" \
214 "\6BUSY"
215
216
217#define kn_id kn_kevent.ident
218#define kn_filter kn_kevent.filter
219#define kn_flags kn_kevent.flags
220#define kn_fflags kn_kevent.fflags
221#define kn_data kn_kevent.data
222};
223
224#include <sys/systm.h> /* for copyin_t */
225
226struct lwp;
227struct timespec;
228
229void kqueue_init(void);
230void knote(struct klist *, long);
231void knote_fdclose(int);
232
233typedef int (*kevent_fetch_changes_t)(void *, const struct kevent *,
234 struct kevent *, size_t, int);
235typedef int (*kevent_put_events_t)(void *, struct kevent *, struct kevent *,
236 size_t, int);
237
238struct kevent_ops {
239 void *keo_private;
240 copyin_t keo_fetch_timeout;
241 kevent_fetch_changes_t keo_fetch_changes;
242 kevent_put_events_t keo_put_events;
243};
244
245
246int kevent_fetch_changes(void *, const struct kevent *, struct kevent *,
247 size_t, int);
248int kevent_put_events(void *, struct kevent *, struct kevent *, size_t,
249 int);
250int kevent1(register_t *, int, const struct kevent *,
251 size_t, struct kevent *, size_t, const struct timespec *,
252 const struct kevent_ops *);
253
254int kfilter_register(const char *, const struct filterops *, int *);
255int kfilter_unregister(const char *);
256
257int filt_seltrue(struct knote *, long);
258extern const struct filterops seltrue_filtops;
259
260extern struct klist fs_klist; /* EVFILT_FS */
261
262#else /* !_KERNEL */
263
264#include <sys/cdefs.h>
265struct timespec;
266
267__BEGIN_DECLS
268#if defined(_NETBSD_SOURCE)
269int kqueue(void);
270int kqueue1(int);
271#ifndef __LIBC12_SOURCE__
272int kevent(int, const struct kevent *, size_t, struct kevent *, size_t,
273 const struct timespec *) __RENAME(__kevent50);
274#endif
275#endif /* !_POSIX_C_SOURCE */
276__END_DECLS
277
278#endif /* !_KERNEL */
279
280#endif /* !_SYS_EVENT_H_ */
281