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/9/sys/sys/event.h 264369 2014-04-12 14:09:35Z kib $
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 #define EV_SET(kevp_, a, b, c, d, e, f) do {	\
48 	struct kevent *kevp = (kevp_);		\
49 	(kevp)->ident = (a);			\
50 	(kevp)->filter = (b);			\
51 	(kevp)->flags = (c);			\
52 	(kevp)->fflags = (d);			\
53 	(kevp)->data = (e);			\
54 	(kevp)->udata = (f);			\
55 } while(0)
56 
57 struct kevent {
58 	uintptr_t	ident;		/* identifier for this event */
59 	short		filter;		/* filter for event */
60 	u_short		flags;
61 	u_int		fflags;
62 	intptr_t	data;
63 	void		*udata;		/* opaque user data identifier */
64 };
65 
66 /* actions */
67 #define EV_ADD		0x0001		/* add event to kq (implies enable) */
68 #define EV_DELETE	0x0002		/* delete event from kq */
69 #define EV_ENABLE	0x0004		/* enable event */
70 #define EV_DISABLE	0x0008		/* disable event (not reported) */
71 
72 /* flags */
73 #define EV_ONESHOT	0x0010		/* only report one occurrence */
74 #define EV_CLEAR	0x0020		/* clear event state after reporting */
75 #define EV_RECEIPT	0x0040		/* force EV_ERROR on success, data=0 */
76 #define EV_DISPATCH	0x0080		/* disable event after reporting */
77 
78 #define EV_SYSFLAGS	0xF000		/* reserved by system */
79 #define	EV_DROP		0x1000		/* note should be dropped */
80 #define EV_FLAG1	0x2000		/* filter-specific flag */
81 
82 /* returned values */
83 #define EV_EOF		0x8000		/* EOF detected */
84 #define EV_ERROR	0x4000		/* error, data contains errno */
85 
86  /*
87   * data/hint flags/masks for EVFILT_USER, shared with userspace
88   *
89   * On input, the top two bits of fflags specifies how the lower twenty four
90   * bits should be applied to the stored value of fflags.
91   *
92   * On output, the top two bits will always be set to NOTE_FFNOP and the
93   * remaining twenty four bits will contain the stored fflags value.
94   */
95 #define NOTE_FFNOP	0x00000000		/* ignore input fflags */
96 #define NOTE_FFAND	0x40000000		/* AND fflags */
97 #define NOTE_FFOR	0x80000000		/* OR fflags */
98 #define NOTE_FFCOPY	0xc0000000		/* copy fflags */
99 #define NOTE_FFCTRLMASK	0xc0000000		/* masks for operations */
100 #define NOTE_FFLAGSMASK	0x00ffffff
101 
102 #define NOTE_TRIGGER	0x01000000		/* Cause the event to be
103 						   triggered for output. */
104 
105 /*
106  * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
107  */
108 #define NOTE_LOWAT	0x0001			/* low water mark */
109 
110 /*
111  * data/hint flags for EVFILT_VNODE, shared with userspace
112  */
113 #define	NOTE_DELETE	0x0001			/* vnode was removed */
114 #define	NOTE_WRITE	0x0002			/* data contents changed */
115 #define	NOTE_EXTEND	0x0004			/* size increased */
116 #define	NOTE_ATTRIB	0x0008			/* attributes changed */
117 #define	NOTE_LINK	0x0010			/* link count changed */
118 #define	NOTE_RENAME	0x0020			/* vnode was renamed */
119 #define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
120 
121 /*
122  * data/hint flags for EVFILT_PROC, shared with userspace
123  */
124 #define	NOTE_EXIT	0x80000000		/* process exited */
125 #define	NOTE_FORK	0x40000000		/* process forked */
126 #define	NOTE_EXEC	0x20000000		/* process exec'd */
127 #define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
128 #define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
129 
130 /* additional flags for EVFILT_PROC */
131 #define	NOTE_TRACK	0x00000001		/* follow across forks */
132 #define	NOTE_TRACKERR	0x00000002		/* could not track child */
133 #define	NOTE_CHILD	0x00000004		/* am a child process */
134 
135 struct knote;
136 SLIST_HEAD(klist, knote);
137 struct kqueue;
138 TAILQ_HEAD(kqlist, kqueue);
139 struct knlist {
140 	struct	klist	kl_list;
141 	void    (*kl_lock)(void *);	/* lock function */
142 	void    (*kl_unlock)(void *);
143 	void	(*kl_assert_locked)(void *);
144 	void	(*kl_assert_unlocked)(void *);
145 	void *kl_lockarg;		/* argument passed to kl_lockf() */
146 };
147 
148 
149 #ifdef _KERNEL
150 
151 #ifdef MALLOC_DECLARE
152 MALLOC_DECLARE(M_KQUEUE);
153 #endif
154 
155 /*
156  * Flags for knote call
157  */
158 #define	KNF_LISTLOCKED	0x0001			/* knlist is locked */
159 #define	KNF_NOKQLOCK	0x0002			/* do not keep KQ_LOCK */
160 
161 #define KNOTE(list, hist, flags)	knote(list, hist, flags)
162 #define KNOTE_LOCKED(list, hint)	knote(list, hint, KNF_LISTLOCKED)
163 #define KNOTE_UNLOCKED(list, hint)	knote(list, hint, 0)
164 
165 #define	KNLIST_EMPTY(list)		SLIST_EMPTY(&(list)->kl_list)
166 
167 /*
168  * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
169  * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
170  */
171 #define NOTE_SIGNAL	0x08000000
172 
173 /*
174  * Hint values for the optional f_touch event filter.  If f_touch is not set
175  * to NULL and f_isfd is zero the f_touch filter will be called with the type
176  * argument set to EVENT_REGISTER during a kevent() system call.  It is also
177  * called under the same conditions with the type argument set to EVENT_PROCESS
178  * when the event has been triggered.
179  */
180 #define EVENT_REGISTER	1
181 #define EVENT_PROCESS	2
182 
183 struct filterops {
184 	int	f_isfd;		/* true if ident == filedescriptor */
185 	int	(*f_attach)(struct knote *kn);
186 	void	(*f_detach)(struct knote *kn);
187 	int	(*f_event)(struct knote *kn, long hint);
188 	void	(*f_touch)(struct knote *kn, struct kevent *kev, u_long type);
189 };
190 
191 /*
192  * Setting the KN_INFLUX flag enables you to unlock the kq that this knote
193  * is on, and modify kn_status as if you had the KQ lock.
194  *
195  * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
196  */
197 struct knote {
198 	SLIST_ENTRY(knote)	kn_link;	/* for kq */
199 	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
200 	struct			knlist *kn_knlist;	/* f_attach populated */
201 	TAILQ_ENTRY(knote)	kn_tqe;
202 	struct			kqueue *kn_kq;	/* which queue we are on */
203 	struct 			kevent kn_kevent;
204 	int			kn_status;	/* protected by kq lock */
205 #define KN_ACTIVE	0x01			/* event has been triggered */
206 #define KN_QUEUED	0x02			/* event is on queue */
207 #define KN_DISABLED	0x04			/* event is disabled */
208 #define KN_DETACHED	0x08			/* knote is detached */
209 #define KN_INFLUX	0x10			/* knote is in flux */
210 #define KN_MARKER	0x20			/* ignore this knote */
211 #define KN_KQUEUE	0x40			/* this knote belongs to a kq */
212 #define KN_HASKQLOCK	0x80			/* for _inevent */
213 #define	KN_SCAN		0x100			/* flux set in kqueue_scan() */
214 	int			kn_sfflags;	/* saved filter flags */
215 	intptr_t		kn_sdata;	/* saved data field */
216 	union {
217 		struct		file *p_fp;	/* file data pointer */
218 		struct		proc *p_proc;	/* proc pointer */
219 		struct		aiocblist *p_aio;	/* AIO job pointer */
220 		struct		aioliojob *p_lio;	/* LIO job pointer */
221 	} kn_ptr;
222 	struct			filterops *kn_fop;
223 	void			*kn_hook;
224 	int			kn_hookid;
225 
226 #define kn_id		kn_kevent.ident
227 #define kn_filter	kn_kevent.filter
228 #define kn_flags	kn_kevent.flags
229 #define kn_fflags	kn_kevent.fflags
230 #define kn_data		kn_kevent.data
231 #define kn_fp		kn_ptr.p_fp
232 };
233 struct kevent_copyops {
234 	void	*arg;
235 	int	(*k_copyout)(void *arg, struct kevent *kevp, int count);
236 	int	(*k_copyin)(void *arg, struct kevent *kevp, int count);
237 };
238 
239 struct thread;
240 struct proc;
241 struct knlist;
242 struct mtx;
243 
244 extern void	knote(struct knlist *list, long hint, int lockflags);
245 extern void	knote_fork(struct knlist *list, int pid);
246 extern void	knlist_add(struct knlist *knl, struct knote *kn, int islocked);
247 extern void	knlist_remove(struct knlist *knl, struct knote *kn, int islocked);
248 extern void	knlist_remove_inevent(struct knlist *knl, struct knote *kn);
249 extern int	knlist_empty(struct knlist *knl);
250 extern void	knlist_init(struct knlist *knl, void *lock,
251     void (*kl_lock)(void *), void (*kl_unlock)(void *),
252     void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *));
253 extern void	knlist_init_mtx(struct knlist *knl, struct mtx *lock);
254 extern void	knlist_destroy(struct knlist *knl);
255 extern void	knlist_cleardel(struct knlist *knl, struct thread *td,
256 	int islocked, int killkn);
257 #define knlist_clear(knl, islocked)				\
258 		knlist_cleardel((knl), NULL, (islocked), 0)
259 #define knlist_delete(knl, td, islocked)			\
260 		knlist_cleardel((knl), (td), (islocked), 1)
261 extern void	knote_fdclose(struct thread *p, int fd);
262 extern int 	kqfd_register(int fd, struct kevent *kev, struct thread *p,
263 		    int waitok);
264 extern int	kqueue_add_filteropts(int filt, struct filterops *filtops);
265 extern int	kqueue_del_filteropts(int filt);
266 
267 #else 	/* !_KERNEL */
268 
269 #include <sys/cdefs.h>
270 struct timespec;
271 
272 __BEGIN_DECLS
273 int     kqueue(void);
274 int     kevent(int kq, const struct kevent *changelist, int nchanges,
275 	    struct kevent *eventlist, int nevents,
276 	    const struct timespec *timeout);
277 __END_DECLS
278 
279 #endif /* !_KERNEL */
280 
281 #endif /* !_SYS_EVENT_H_ */
282