Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

- kqueue_scan: work around problem noted by yamt@: if an event fires while 

we have unlocked the kqueue to check its state, leave it queued and
  re-check later.
- knote_dequeue: fold into knote_detach since nothing else uses it.
- Note a couple more problems.
This commit is contained in:
ad 2008-03-26 13:32:32 +00:00
parent 0e8428c0f6
commit 78656b1e91
1 changed files with 25 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
sys/kern/kern_event.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: kern_event.c,v 1.52 2008/03/24 09:09:55 yamt Exp $ */
/* $NetBSD: kern_event.c,v 1.53 2008/03/26 13:32:32 ad Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@ -62,7 +62,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_event.c,v 1.52 2008/03/24 09:09:55 yamt Exp $");
__KERNEL_RCSID(0, "$NetBSD: kern_event.c,v 1.53 2008/03/26 13:32:32 ad Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@ -98,7 +98,6 @@ static void kqueue_doclose(struct kqueue *, struct klist *, int);
static void knote_detach(struct knote *, filedesc_t *fdp, bool);
static void knote_enqueue(struct knote *);
static void knote_dequeue(struct knote *);
static void knote_activate(struct knote *);
static void filt_kqdetach(struct knote *);
@ -1157,17 +1156,20 @@ kqueue_scan(file_t *fp, size_t maxevents, struct kevent *ulistp,
KERNEL_LOCK(1, NULL); /* XXXSMP */
rv = (*kn->kn_fop->f_event)(kn, 0);
KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */
mutex_spin_enter(&kq->kq_lock);
/* Re-poll if note was re-enqueued. */
if ((kn->kn_status & KN_QUEUED) != 0)
continue;
if (rv == 0) {
/*
* non-ONESHOT event that hasn't
* triggered again, so de-queue.
*/
mutex_spin_enter(&kq->kq_lock);
kn->kn_status &= ~KN_ACTIVE;
continue;
}
mutex_spin_enter(&kq->kq_lock);
}
/* XXXAD should be got from f_event if !oneshot. */
*kevp++ = kn->kn_kevent;
nkev++;
if (kn->kn_flags & EV_ONESHOT) {
@ -1466,23 +1468,40 @@ static void
knote_detach(struct knote *kn, filedesc_t *fdp, bool dofop)
{
struct klist *list;
struct kqueue *kq;
kq = kn->kn_kq;
KASSERT((kn->kn_status & KN_MARKER) == 0);
KASSERT(mutex_owned(&fdp->fd_lock));
/* Remove from monitored object. */
if (dofop) {
KERNEL_LOCK(1, NULL); /* XXXSMP */
(*kn->kn_fop->f_detach)(kn);
KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */
}
/* Remove from descriptor table. */
if (kn->kn_fop->f_isfd)
list = (struct klist *)&fdp->fd_ofiles[kn->kn_id]->ff_knlist;
else
list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
SLIST_REMOVE(list, kn, knote, kn_link);
knote_dequeue(kn);
/* Remove from kqueue. */
/* XXXAD should verify not in use by kqueue_scan. */
mutex_spin_enter(&kq->kq_lock);
if ((kn->kn_status & KN_QUEUED) != 0) {
kq_check(kq);
TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
kn->kn_status &= ~KN_QUEUED;
kq->kq_count--;
kq_check(kq);
}
mutex_spin_exit(&kq->kq_lock);
mutex_exit(&fdp->fd_lock);
if (kn->kn_fop->f_isfd)
fd_putfile(kn->kn_id);
@ -1517,30 +1536,6 @@ knote_enqueue(struct knote *kn)
}
mutex_spin_exit(&kq->kq_lock);
}
/*
* Dequeue event for knote.
*/
static void
knote_dequeue(struct knote *kn)
{
struct kqueue *kq;
KASSERT((kn->kn_status & KN_MARKER) == 0);
kq = kn->kn_kq;
mutex_spin_enter(&kq->kq_lock);
if ((kn->kn_status & KN_QUEUED) != 0) {
kq_check(kq);
TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
kn->kn_status &= ~KN_QUEUED;
kq->kq_count--;
kq_check(kq);
}
mutex_spin_exit(&kq->kq_lock);
}
/*
* Queue new event for knote.
*/