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: stable/10/sys/sys/event.h 336647 2018-07-23 18:47:04Z dab $
27 */
28
29#ifndef _SYS_EVENT_H_
30#define _SYS_EVENT_H_
31
32#include <sys/queue.h>
33
34#define EVFILT_READ		(-1)
35#define EVFILT_WRITE		(-2)
36#define EVFILT_AIO		(-3)	/* attached to aio requests */
37#define EVFILT_VNODE		(-4)	/* attached to vnodes */
38#define EVFILT_PROC		(-5)	/* attached to struct proc */
39#define EVFILT_SIGNAL		(-6)	/* attached to struct proc */
40#define EVFILT_TIMER		(-7)	/* timers */
41/*	EVFILT_NETDEV		(-8)	   no longer supported */
42#define EVFILT_FS		(-9)	/* filesystem events */
43#define EVFILT_LIO		(-10)	/* attached to lio requests */
44#define EVFILT_USER		(-11)	/* User events */
45#define EVFILT_SYSCOUNT		11
46
47#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
48#define	EV_SET(kevp_, a, b, c, d, e, f) do {	\
49	*(kevp_) = (struct kevent){		\
50	    .ident = (a),			\
51	    .filter = (b),			\
52	    .flags = (c),			\
53	    .fflags = (d),			\
54	    .data = (e),			\
55	    .udata = (f),			\
56	};					\
57} while(0)
58#else /* Pre-C99 or not STDC (e.g., C++) */
59/* The definition of the local variable kevp could possibly conflict
60 * with a user-defined value passed in parameters a-f.
61 */
62#define EV_SET(kevp_, a, b, c, d, e, f) do {	\
63	struct kevent *kevp = (kevp_);		\
64	(kevp)->ident = (a);			\
65	(kevp)->filter = (b);			\
66	(kevp)->flags = (c);			\
67	(kevp)->fflags = (d);			\
68	(kevp)->data = (e);			\
69	(kevp)->udata = (f);			\
70} while(0)
71#endif
72
73struct kevent {
74	uintptr_t	ident;		/* identifier for this event */
75	short		filter;		/* filter for event */
76	u_short		flags;		/* action flags for kqueue */
77	u_int		fflags;		/* filter flag value */
78	intptr_t	data;		/* filter data value */
79	void		*udata;		/* opaque user data identifier */
80};
81
82/* actions */
83#define EV_ADD		0x0001		/* add event to kq (implies enable) */
84#define EV_DELETE	0x0002		/* delete event from kq */
85#define EV_ENABLE	0x0004		/* enable event */
86#define EV_DISABLE	0x0008		/* disable event (not reported) */
87
88/* flags */
89#define EV_ONESHOT	0x0010		/* only report one occurrence */
90#define EV_CLEAR	0x0020		/* clear event state after reporting */
91#define EV_RECEIPT	0x0040		/* force EV_ERROR on success, data=0 */
92#define EV_DISPATCH	0x0080		/* disable event after reporting */
93
94#define EV_SYSFLAGS	0xF000		/* reserved by system */
95#define	EV_DROP		0x1000		/* note should be dropped */
96#define EV_FLAG1	0x2000		/* filter-specific flag */
97#define EV_FLAG2	0x4000		/* filter-specific flag */
98
99/* returned values */
100#define EV_EOF		0x8000		/* EOF detected */
101#define EV_ERROR	0x4000		/* error, data contains errno */
102
103 /*
104  * data/hint flags/masks for EVFILT_USER, shared with userspace
105  *
106  * On input, the top two bits of fflags specifies how the lower twenty four
107  * bits should be applied to the stored value of fflags.
108  *
109  * On output, the top two bits will always be set to NOTE_FFNOP and the
110  * remaining twenty four bits will contain the stored fflags value.
111  */
112#define NOTE_FFNOP	0x00000000		/* ignore input fflags */
113#define NOTE_FFAND	0x40000000		/* AND fflags */
114#define NOTE_FFOR	0x80000000		/* OR fflags */
115#define NOTE_FFCOPY	0xc0000000		/* copy fflags */
116#define NOTE_FFCTRLMASK	0xc0000000		/* masks for operations */
117#define NOTE_FFLAGSMASK	0x00ffffff
118
119#define NOTE_TRIGGER	0x01000000		/* Cause the event to be
120						   triggered for output. */
121
122/*
123 * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
124 */
125#define NOTE_LOWAT	0x0001			/* low water mark */
126
127/*
128 * data/hint flags for EVFILT_VNODE, shared with userspace
129 */
130#define	NOTE_DELETE	0x0001			/* vnode was removed */
131#define	NOTE_WRITE	0x0002			/* data contents changed */
132#define	NOTE_EXTEND	0x0004			/* size increased */
133#define	NOTE_ATTRIB	0x0008			/* attributes changed */
134#define	NOTE_LINK	0x0010			/* link count changed */
135#define	NOTE_RENAME	0x0020			/* vnode was renamed */
136#define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
137#define	NOTE_OPEN	0x0080			/* vnode was opened */
138#define	NOTE_CLOSE	0x0100			/* file closed, fd did not
139						   allowed write */
140#define	NOTE_CLOSE_WRITE 0x0200			/* file closed, fd did allowed
141						   write */
142#define	NOTE_READ	0x0400			/* file was read */
143
144/*
145 * data/hint flags for EVFILT_PROC, shared with userspace
146 */
147#define	NOTE_EXIT	0x80000000		/* process exited */
148#define	NOTE_FORK	0x40000000		/* process forked */
149#define	NOTE_EXEC	0x20000000		/* process exec'd */
150#define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
151#define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
152
153/* additional flags for EVFILT_PROC */
154#define	NOTE_TRACK	0x00000001		/* follow across forks */
155#define	NOTE_TRACKERR	0x00000002		/* could not track child */
156#define	NOTE_CHILD	0x00000004		/* am a child process */
157
158/* additional flags for EVFILE_TIMER */
159#define NOTE_SECONDS		0x00000001	/* data is seconds */
160#define NOTE_MSECONDS		0x00000002	/* data is milliseconds */
161#define NOTE_USECONDS		0x00000004	/* data is microseconds */
162#define NOTE_NSECONDS		0x00000008	/* data is nanoseconds */
163
164struct knote;
165SLIST_HEAD(klist, knote);
166struct kqueue;
167TAILQ_HEAD(kqlist, kqueue);
168struct knlist {
169	struct	klist	kl_list;
170	void    (*kl_lock)(void *);	/* lock function */
171	void    (*kl_unlock)(void *);
172	void	(*kl_assert_locked)(void *);
173	void	(*kl_assert_unlocked)(void *);
174	void *kl_lockarg;		/* argument passed to kl_lockf() */
175};
176
177
178#ifdef _KERNEL
179
180/*
181 * Flags for knote call
182 */
183#define	KNF_LISTLOCKED	0x0001			/* knlist is locked */
184#define	KNF_NOKQLOCK	0x0002			/* do not keep KQ_LOCK */
185
186#define KNOTE(list, hist, flags)	knote(list, hist, flags)
187#define KNOTE_LOCKED(list, hint)	knote(list, hint, KNF_LISTLOCKED)
188#define KNOTE_UNLOCKED(list, hint)	knote(list, hint, 0)
189
190#define	KNLIST_EMPTY(list)		SLIST_EMPTY(&(list)->kl_list)
191
192/*
193 * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
194 * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
195 */
196#define NOTE_SIGNAL	0x08000000
197
198/*
199 * Hint values for the optional f_touch event filter.  If f_touch is not set
200 * to NULL and f_isfd is zero the f_touch filter will be called with the type
201 * argument set to EVENT_REGISTER during a kevent() system call.  It is also
202 * called under the same conditions with the type argument set to EVENT_PROCESS
203 * when the event has been triggered.
204 */
205#define EVENT_REGISTER	1
206#define EVENT_PROCESS	2
207
208struct filterops {
209	int	f_isfd;		/* true if ident == filedescriptor */
210	int	(*f_attach)(struct knote *kn);
211	void	(*f_detach)(struct knote *kn);
212	int	(*f_event)(struct knote *kn, long hint);
213	void	(*f_touch)(struct knote *kn, struct kevent *kev, u_long type);
214};
215
216/*
217 * Setting the KN_INFLUX flag enables you to unlock the kq that this knote
218 * is on, and modify kn_status as if you had the KQ lock.
219 *
220 * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
221 */
222struct knote {
223	SLIST_ENTRY(knote)	kn_link;	/* for kq */
224	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
225	struct			knlist *kn_knlist;	/* f_attach populated */
226	TAILQ_ENTRY(knote)	kn_tqe;
227	struct			kqueue *kn_kq;	/* which queue we are on */
228	struct 			kevent kn_kevent;
229	int			kn_status;	/* protected by kq lock */
230#define KN_ACTIVE	0x01			/* event has been triggered */
231#define KN_QUEUED	0x02			/* event is on queue */
232#define KN_DISABLED	0x04			/* event is disabled */
233#define KN_DETACHED	0x08			/* knote is detached */
234#define KN_INFLUX	0x10			/* knote is in flux */
235#define KN_MARKER	0x20			/* ignore this knote */
236#define KN_KQUEUE	0x40			/* this knote belongs to a kq */
237#define KN_HASKQLOCK	0x80			/* for _inevent */
238#define	KN_SCAN		0x100			/* flux set in kqueue_scan() */
239	int			kn_sfflags;	/* saved filter flags */
240	intptr_t		kn_sdata;	/* saved data field */
241	union {
242		struct		file *p_fp;	/* file data pointer */
243		struct		proc *p_proc;	/* proc pointer */
244		struct		aiocblist *p_aio;	/* AIO job pointer */
245		struct		aioliojob *p_lio;	/* LIO job pointer */
246		sbintime_t	*p_nexttime;	/* next timer event fires at */
247		void		*p_v;		/* generic other pointer */
248	} kn_ptr;
249	struct			filterops *kn_fop;
250	void			*kn_hook;
251	int			kn_hookid;
252
253#define kn_id		kn_kevent.ident
254#define kn_filter	kn_kevent.filter
255#define kn_flags	kn_kevent.flags
256#define kn_fflags	kn_kevent.fflags
257#define kn_data		kn_kevent.data
258#define kn_fp		kn_ptr.p_fp
259};
260struct kevent_copyops {
261	void	*arg;
262	int	(*k_copyout)(void *arg, struct kevent *kevp, int count);
263	int	(*k_copyin)(void *arg, struct kevent *kevp, int count);
264};
265
266struct thread;
267struct proc;
268struct knlist;
269struct mtx;
270struct rwlock;
271
272void	knote(struct knlist *list, long hint, int lockflags);
273void	knote_fork(struct knlist *list, int pid);
274void	knlist_add(struct knlist *knl, struct knote *kn, int islocked);
275void	knlist_remove(struct knlist *knl, struct knote *kn, int islocked);
276void	knlist_remove_inevent(struct knlist *knl, struct knote *kn);
277int	knlist_empty(struct knlist *knl);
278void	knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *),
279    void (*kl_unlock)(void *), void (*kl_assert_locked)(void *),
280    void (*kl_assert_unlocked)(void *));
281void	knlist_init_mtx(struct knlist *knl, struct mtx *lock);
282void	knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock);
283void	knlist_destroy(struct knlist *knl);
284void	knlist_cleardel(struct knlist *knl, struct thread *td,
285	int islocked, int killkn);
286#define knlist_clear(knl, islocked)				\
287	knlist_cleardel((knl), NULL, (islocked), 0)
288#define knlist_delete(knl, td, islocked)			\
289	knlist_cleardel((knl), (td), (islocked), 1)
290void	knote_fdclose(struct thread *p, int fd);
291int 	kqfd_register(int fd, struct kevent *kev, struct thread *p,
292	    int waitok);
293int	kqueue_add_filteropts(int filt, struct filterops *filtops);
294int	kqueue_del_filteropts(int filt);
295
296#else 	/* !_KERNEL */
297
298#include <sys/cdefs.h>
299struct timespec;
300
301__BEGIN_DECLS
302int     kqueue(void);
303int     kevent(int kq, const struct kevent *changelist, int nchanges,
304	    struct kevent *eventlist, int nevents,
305	    const struct timespec *timeout);
306__END_DECLS
307
308#endif /* !_KERNEL */
309
310#endif /* !_SYS_EVENT_H_ */
311