freebsd-skq/sys/sys/eventvar.h
jmg bc1805c6e8 Add locking to the kqueue subsystem. This also makes the kqueue subsystem
a more complete subsystem, and removes the knowlege of how things are
implemented from the drivers.  Include locking around filter ops, so a
module like aio will know when not to be unloaded if there are outstanding
knotes using it's filter ops.

Currently, it uses the MTX_DUPOK even though it is not always safe to
aquire duplicate locks.  Witness currently doesn't support the ability
to discover if a dup lock is ok (in some cases).

Reviewed by:	green, rwatson (both earlier versions)
2004-08-15 06:24:42 +00:00

66 lines
2.4 KiB
C

/*-
* Copyright (c) 1999,2000 Jonathan Lemon <jlemon@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SYS_EVENTVAR_H_
#define _SYS_EVENTVAR_H_
#ifndef _KERNEL
#error "no user-servicable parts inside"
#endif
#include <sys/_task.h>
#define KQ_NEVENTS 8 /* minimize copy{in,out} calls */
#define KQEXTENT 256 /* linear growth by this amount */
struct kqueue {
struct mtx kq_lock;
int kq_refcnt;
SLIST_ENTRY(kqueue) kq_list;
TAILQ_HEAD(, knote) kq_head; /* list of pending event */
int kq_count; /* number of pending events */
struct selinfo kq_sel;
struct sigio *kq_sigio;
struct filedesc *kq_fdp;
int kq_state;
#define KQ_SEL 0x01
#define KQ_SLEEP 0x02
#define KQ_FLUXWAIT 0x04 /* waiting for a in flux kn */
#define KQ_ASYNC 0x08
#define KQ_CLOSING 0x10
#define KQ_TASKSCHED 0x20 /* task scheduled */
#define KQ_TASKDRAIN 0x40 /* waiting for task to drain */
int kq_knlistsize; /* size of knlist */
struct klist *kq_knlist; /* list of knotes */
u_long kq_knhashmask; /* size of knhash */
struct klist *kq_knhash; /* hash table for knotes */
struct task kq_task;
};
#endif /* !_SYS_EVENTVAR_H_ */