xref: /openbsd/sys/sys/eventvar.h (revision a820167a)
1 /*	$OpenBSD: eventvar.h,v 1.17 2022/07/09 12:48:21 visa Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999,2000 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/eventvar.h,v 1.3 2000/05/26 02:06:54 jake Exp $
29  */
30 
31 #ifndef _SYS_EVENTVAR_H_
32 #define _SYS_EVENTVAR_H_
33 
34 #include <sys/mutex.h>
35 #include <sys/refcnt.h>
36 #include <sys/task.h>
37 
38 #define KQ_NEVENTS	8		/* minimize copy{in,out} calls */
39 #define KQEXTENT	256		/* linear growth by this amount */
40 
41 /*
42  * Locking:
43  *	I	immutable after creation
44  *	L	kqueue_klist_lock
45  *	a	atomic operations
46  *	q	kq_lock
47  */
48 struct kqueue {
49 	struct		mutex kq_lock;		/* lock for queue access */
50 	TAILQ_HEAD(, knote) kq_head;		/* [q] list of pending event */
51 	int		kq_count;		/* [q] # of pending events */
52 	struct		refcnt kq_refcnt;	/* [a] # of references */
53 	struct		klist kq_klist;		/* [L] knotes of other kqs */
54 	struct		filedesc *kq_fdp;	/* [I] fd table of this kq */
55 
56 	LIST_ENTRY(kqueue) kq_next;
57 
58 	u_int		kq_nknotes;		/* [q] # of registered knotes */
59 
60 	int		kq_knlistsize;		/* [q] size of kq_knlist */
61 	struct		knlist *kq_knlist;	/* [q] list of
62 						 *     attached knotes */
63 	u_long		kq_knhashmask;		/* [q] size of kq_knhash */
64 	struct		knlist *kq_knhash;	/* [q] hash table for
65 						 *     attached knotes */
66 	struct		task kq_task;		/* deferring of activation */
67 
68 	int		kq_state;		/* [q] */
69 #define KQ_SLEEP	0x02
70 #define KQ_DYING	0x04
71 #define KQ_TASK		0x08
72 };
73 
74 #endif /* !_SYS_EVENTVAR_H_ */
75