File: [local] / src / sys / kern / kern_event.c (download)
Revision 1.7, Thu Mar 1 20:54:33 2001 UTC (23 years, 3 months ago) by provos
Branch: MAIN
CVS Tags: OPENBSD_2_9_BASE, OPENBSD_2_9 Changes since 1.6: +67 -83 lines
port kqueue changes from freebsd, plus all required openbsd glue.
okay deraadt@, millert@
from jlemon@freebsd.org:
extend kqueue down to the device layer, backwards compatible approach
suggested by peter@freebsd.org
|
/* $OpenBSD: kern_event.c,v 1.7 2001/03/01 20:54:33 provos Exp $ */
/*-
* Copyright (c) 1999,2000,2001 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: src/sys/kern/kern_event.c,v 1.22 2001/02/23 20:32:42 jlemon Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/unistd.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/fcntl.h>
#include <sys/select.h>
#include <sys/queue.h>
#include <sys/event.h>
#include <sys/eventvar.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
int kqueue_scan(struct file *fp, int maxevents,
struct kevent *ulistp, const struct timespec *timeout,
struct proc *p, int *retval);
int kqueue_read(struct file *fp, off_t *poff, struct uio *uio,
struct ucred *cred);
int kqueue_write(struct file *fp, off_t *poff, struct uio *uio,
struct ucred *cred);
int kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
struct proc *p);
int kqueue_select(struct file *fp, int which, struct proc *p);
int kqueue_kqfilter(struct file *fp, struct knote *kn);
int kqueue_close(struct file *fp, struct proc *p);
void kqueue_wakeup(struct kqueue *kq);
struct fileops kqueueops = {
kqueue_read,
kqueue_write,
kqueue_ioctl,
kqueue_select,
kqueue_kqfilter,
kqueue_close
};
void knote_attach(struct knote *kn, struct filedesc *fdp);
void knote_drop(struct knote *kn, struct proc *p);
void knote_enqueue(struct knote *kn);
void knote_dequeue(struct knote *kn);
struct knote *knote_alloc(void);
void knote_free(struct knote *kn);
void filt_kqdetach(struct knote *kn);
int filt_kqueue(struct knote *kn, long hint);
int filt_procattach(struct knote *kn);
void filt_procdetach(struct knote *kn);
int filt_proc(struct knote *kn, long hint);
int filt_fileattach(struct knote *kn);
struct filterops kqread_filtops =
{ 1, NULL, filt_kqdetach, filt_kqueue };
struct filterops proc_filtops =
{ 0, filt_procattach, filt_procdetach, filt_proc };
struct filterops file_filtops =
{ 1, filt_fileattach, NULL, NULL };
#define KNOTE_ACTIVATE(kn) do { \
kn->kn_status |= KN_ACTIVE; \
if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
knote_enqueue(kn); \
} while(0)
#define KN_HASHSIZE 64 /* XXX should be tunable */
#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
extern struct filterops sig_filtops;
#ifdef notyet
extern struct filterops aio_filtops;
#endif
/*
* Table for for all system-defined filters.
*/
struct filterops *sysfilt_ops[] = {
&file_filtops, /* EVFILT_READ */
&file_filtops, /* EVFILT_WRITE */
NULL, /*&aio_filtops,*/ /* EVFILT_AIO */
&file_filtops, /* EVFILT_VNODE */
&proc_filtops, /* EVFILT_PROC */
&sig_filtops, /* EVFILT_SIGNAL */
};
int
filt_fileattach(struct knote *kn)
{
struct file *fp = kn->kn_fp;
return ((*fp->f_ops->fo_kqfilter)(fp, kn));
}
int
kqueue_kqfilter(struct file *fp, struct knote *kn)
{
struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
if (kn->kn_filter != EVFILT_READ)
return (1);
kn->kn_fop = &kqread_filtops;
SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext);
return (0);
}
void
filt_kqdetach(struct knote *kn)
{
struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext);
}
/*ARGSUSED*/
int
filt_kqueue(struct knote *kn, long hint)
{
struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
kn->kn_data = kq->kq_count;
return (kn->kn_data > 0);
}
int
filt_procattach(struct knote *kn)
{
struct proc *p;
p = pfind(kn->kn_id);
if (p == NULL)
return (ESRCH);
/*
* Fail if it's not owned by you, or the last exec gave us
* setuid/setgid privs (unless you're root).
*/
if ((p->p_cred->p_ruid != curproc->p_cred->p_ruid ||
(p->p_flag & P_SUGID)) &&
suser(curproc->p_ucred, &curproc->p_acflag) != 0)
return (EACCES);
kn->kn_ptr.p_proc = p;
kn->kn_flags |= EV_CLEAR; /* automatically set */
/*
* internal flag indicating registration done by kernel
*/
if (kn->kn_flags & EV_FLAG1) {
kn->kn_data = kn->kn_sdata; /* ppid */
kn->kn_fflags = NOTE_CHILD;
kn->kn_flags &= ~EV_FLAG1;
}
/* XXX lock the proc here while adding to the list? */
SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
return (0);
}
/*
* The knote may be attached to a different process, which may exit,
* leaving nothing for the knote to be attached to. So when the process
* exits, the knote is marked as DETACHED and also flagged as ONESHOT so
* it will be deleted when read out. However, as part of the knote deletion,
* this routine is called, so a check is needed to avoid actually performing
* a detach, because the original process does not exist any more.
*/
void
filt_procdetach(struct knote *kn)
{
struct proc *p = kn->kn_ptr.p_proc;
if (kn->kn_status & KN_DETACHED)
return;
/* XXX locking? this might modify another process. */
SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
}
int
filt_proc(struct knote *kn, long hint)
{
u_int event;
/*
* mask off extra data
*/
event = (u_int)hint & NOTE_PCTRLMASK;
/*
* if the user is interested in this event, record it.
*/
if (kn->kn_sfflags & event)
kn->kn_fflags |= event;
/*
* process is gone, so flag the event as finished.
*/
if (event == NOTE_EXIT) {
kn->kn_status |= KN_DETACHED;
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
return (1);
}
/*
* process forked, and user wants to track the new process,
* so attach a new knote to it, and immediately report an
* event with the parent's pid.
*/
if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) {
struct kevent kev;
int error;
/*
* register knote with new process.
*/
kev.ident = hint & NOTE_PDATAMASK; /* pid */
kev.filter = kn->kn_filter;
kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
kev.fflags = kn->kn_sfflags;
kev.data = kn->kn_id; /* parent */
kev.udata = kn->kn_kevent.udata; /* preserve udata */
error = kqueue_register(kn->kn_kq, &kev, NULL);
if (error)
kn->kn_fflags |= NOTE_TRACKERR;
}
return (kn->kn_fflags != 0);
}
int
sys_kqueue(struct proc *p, void *v, register_t *retval)
{
struct filedesc *fdp = p->p_fd;
struct kqueue *kq;
struct file *fp;
int fd, error;
error = falloc(p, &fp, &fd);
if (error)
return (error);
fp->f_flag = FREAD | FWRITE;
fp->f_type = DTYPE_KQUEUE;
fp->f_ops = &kqueueops;
kq = malloc(sizeof(struct kqueue), M_TEMP, M_WAITOK);
bzero(kq, sizeof(*kq));
TAILQ_INIT(&kq->kq_head);
fp->f_data = (caddr_t)kq;
*retval = fd;
if (fdp->fd_knlistsize < 0)
fdp->fd_knlistsize = 0; /* this process has a kq */
kq->kq_fdp = fdp;
return (error);
}
int
sys_kevent(struct proc *p, void *v, register_t *retval)
{
struct filedesc* fdp = p->p_fd;
struct sys_kevent_args /* {
syscallarg(int) fd;
syscallarg(const struct kevent *) changelist;
syscallarg(int) nchanges;
syscallarg(struct kevent *) eventlist;
syscallarg(int) nevents;
syscallarg(const struct timespec *) timeout;
} */ *uap = v;
struct kevent *kevp;
struct kqueue *kq;
struct file *fp = NULL;
struct timespec ts;
int i, n, nerrors, error;
if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
(fp->f_type != DTYPE_KQUEUE))
return (EBADF);
fp->f_count++;
if (SCARG(uap, timeout) != NULL) {
error = copyin(SCARG(uap, timeout), &ts, sizeof(ts));
if (error)
goto done;
SCARG(uap, timeout) = &ts;
}
kq = (struct kqueue *)fp->f_data;
nerrors = 0;
while (SCARG(uap, nchanges) > 0) {
n = SCARG(uap, nchanges) > KQ_NEVENTS
? KQ_NEVENTS : SCARG(uap, nchanges);
error = copyin(SCARG(uap, changelist), kq->kq_kev,
n * sizeof(struct kevent));
if (error)
goto done;
for (i = 0; i < n; i++) {
kevp = &kq->kq_kev[i];
kevp->flags &= ~EV_SYSFLAGS;
error = kqueue_register(kq, kevp, p);
if (error) {
if (SCARG(uap, nevents) != 0) {
kevp->flags = EV_ERROR;
kevp->data = error;
(void) copyout((caddr_t)kevp,
(caddr_t)SCARG(uap, eventlist),
sizeof(*kevp));
SCARG(uap, eventlist)++;
SCARG(uap, nevents)--;
nerrors++;
} else {
goto done;
}
}
}
SCARG(uap, nchanges) -= n;
SCARG(uap, changelist) += n;
}
if (nerrors) {
*retval = nerrors;
error = 0;
goto done;
}
error = kqueue_scan(fp, SCARG(uap, nevents), SCARG(uap, eventlist),
SCARG(uap, timeout), p, &n);
*retval = n;
done:
if (fp != NULL)
closef(fp, p);
return (error);
}
int
kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
{
struct filedesc *fdp = kq->kq_fdp;
struct filterops *fops = NULL;
struct file *fp = NULL;
struct knote *kn = NULL;
int s, error = 0;
if (kev->filter < 0) {
if (kev->filter + EVFILT_SYSCOUNT < 0)
return (EINVAL);
fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
}
if (fops == NULL) {
/*
* XXX
* filter attach routine is responsible for insuring that
* the identifier can be attached to it.
*/
printf("unknown filter: %d\n", kev->filter);
return (EINVAL);
}
if (fops->f_isfd) {
/* validate descriptor */
if ((u_int)kev->ident >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[kev->ident]) == NULL)
return (EBADF);
fp->f_count++;
if (kev->ident < fdp->fd_knlistsize) {
SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link)
if (kq == kn->kn_kq &&
kev->filter == kn->kn_filter)
break;
}
} else {
if (fdp->fd_knhashmask != 0) {
struct klist *list;
list = &fdp->fd_knhash[
KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)];
SLIST_FOREACH(kn, list, kn_link)
if (kev->ident == kn->kn_id &&
kq == kn->kn_kq &&
kev->filter == kn->kn_filter)
break;
}
}
if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
error = ENOENT;
goto done;
}
/*
* kn now contains the matching knote, or NULL if no match
*/
if (kev->flags & EV_ADD) {
if (kn == NULL) {
kn = knote_alloc();
if (kn == NULL) {
error = ENOMEM;
goto done;
}
kn->kn_fp = fp;
kn->kn_kq = kq;
kn->kn_fop = fops;
/*
* apply reference count to knote structure, and
* do not release it at the end of this routine.
*/
fp = NULL;
kn->kn_sfflags = kev->fflags;
kn->kn_sdata = kev->data;
kev->fflags = 0;
kev->data = 0;
kn->kn_kevent = *kev;
knote_attach(kn, fdp);
if ((error = fops->f_attach(kn)) != 0) {
knote_drop(kn, p);
goto done;
}
} else {
/*
* The user may change some filter values after the
* initial EV_ADD, but doing so will not reset any
* filter which have already been triggered.
*/
kn->kn_sfflags = kev->fflags;
kn->kn_sdata = kev->data;
kn->kn_kevent.udata = kev->udata;
}
s = splhigh();
if (kn->kn_fop->f_event(kn, 0))
KNOTE_ACTIVATE(kn);
splx(s);
} else if (kev->flags & EV_DELETE) {
kn->kn_fop->f_detach(kn);
knote_drop(kn, p);
goto done;
}
if ((kev->flags & EV_DISABLE) &&
((kn->kn_status & KN_DISABLED) == 0)) {
s = splhigh();
kn->kn_status |= KN_DISABLED;
splx(s);
}
if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
s = splhigh();
kn->kn_status &= ~KN_DISABLED;
if ((kn->kn_status & KN_ACTIVE) &&
((kn->kn_status & KN_QUEUED) == 0))
knote_enqueue(kn);
splx(s);
}
done:
if (fp != NULL)
closef(fp, p);
return (error);
}
int
kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp,
const struct timespec *tsp, struct proc *p, int *retval)
{
struct kqueue *kq = (struct kqueue *)fp->f_data;
struct kevent *kevp;
struct timeval atv;
struct knote *kn, marker;
int s, count, timeout, nkev = 0, error = 0;
count = maxevents;
if (count == 0)
goto done;
if (tsp != NULL) {
TIMESPEC_TO_TIMEVAL(&atv, tsp);
if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) {
/* No timeout, just poll */
timeout = -1;
goto start;
}
if (itimerfix(&atv)) {
error = EINVAL;
goto done;
}
s = splclock();
timeradd(&atv, &time, &atv);
timeout = hzto(&atv);
splx(s);
} else {
atv.tv_sec = 0;
atv.tv_usec = 0;
timeout = 0;
}
goto start;
retry:
if (atv.tv_sec || atv.tv_usec) {
timeout = hzto(&atv);
if (timeout <= 0)
goto done;
}
start:
kevp = kq->kq_kev;
s = splhigh();
if (kq->kq_count == 0) {
if (timeout < 0) {
error = EWOULDBLOCK;
} else {
kq->kq_state |= KQ_SLEEP;
error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout);
}
splx(s);
if (error == 0)
goto retry;
/* don't restart after signals... */
if (error == ERESTART)
error = EINTR;
else if (error == EWOULDBLOCK)
error = 0;
goto done;
}
TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe);
while (count) {
kn = TAILQ_FIRST(&kq->kq_head);
TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
if (kn == &marker) {
splx(s);
if (count == maxevents)
goto retry;
goto done;
}
if (kn->kn_status & KN_DISABLED) {
kn->kn_status &= ~KN_QUEUED;
kq->kq_count--;
continue;
}
if ((kn->kn_flags & EV_ONESHOT) == 0 &&
kn->kn_fop->f_event(kn, 0) == 0) {
kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
kq->kq_count--;
continue;
}
*kevp = kn->kn_kevent;
kevp++;
nkev++;
if (kn->kn_flags & EV_ONESHOT) {
kn->kn_status &= ~KN_QUEUED;
kq->kq_count--;
splx(s);
kn->kn_fop->f_detach(kn);
knote_drop(kn, p);
s = splhigh();
} else if (kn->kn_flags & EV_CLEAR) {
kn->kn_data = 0;
kn->kn_fflags = 0;
kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
kq->kq_count--;
} else {
TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
}
count--;
if (nkev == KQ_NEVENTS) {
splx(s);
error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
sizeof(struct kevent) * nkev);
ulistp += nkev;
nkev = 0;
kevp = kq->kq_kev;
s = splhigh();
if (error)
break;
}
}
TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe);
splx(s);
done:
if (nkev != 0)
error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
sizeof(struct kevent) * nkev);
*retval = maxevents - count;
return (error);
}
/*
* XXX
* This could be expanded to call kqueue_scan, if desired.
*/
/*ARGSUSED*/
int
kqueue_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred)
{
return (ENXIO);
}
/*ARGSUSED*/
int
kqueue_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred)
{
return (ENXIO);
}
/*ARGSUSED*/
int
kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p)
{
return (ENOTTY);
}
/*ARGSUSED*/
int
kqueue_select(struct file *fp, int which, struct proc *p)
{
struct kqueue *kq = (struct kqueue *)fp->f_data;
int res = 0;
int s = splnet();
if (which == FREAD) {
if (kq->kq_count) {
res = 1;
} else {
selrecord(p, &kq->kq_sel);
kq->kq_state |= KQ_SEL;
}
}
splx(s);
return (res);
}
/*ARGSUSED*/
int
kqueue_close(struct file *fp, struct proc *p)
{
struct kqueue *kq = (struct kqueue *)fp->f_data;
struct filedesc *fdp = p->p_fd;
struct knote **knp, *kn, *kn0;
int i;
for (i = 0; i < fdp->fd_knlistsize; i++) {
knp = &SLIST_FIRST(&fdp->fd_knlist[i]);
kn = *knp;
while (kn != NULL) {
kn0 = SLIST_NEXT(kn, kn_link);
if (kq == kn->kn_kq) {
kn->kn_fop->f_detach(kn);
closef(kn->kn_fp, p);
knote_free(kn);
*knp = kn0;
} else {
knp = &SLIST_NEXT(kn, kn_link);
}
kn = kn0;
}
}
if (fdp->fd_knhashmask != 0) {
for (i = 0; i < fdp->fd_knhashmask + 1; i++) {
knp = &SLIST_FIRST(&fdp->fd_knhash[i]);
kn = *knp;
while (kn != NULL) {
kn0 = SLIST_NEXT(kn, kn_link);
if (kq == kn->kn_kq) {
kn->kn_fop->f_detach(kn);
/* XXX non-fd release of kn->kn_ptr */
knote_free(kn);
*knp = kn0;
} else {
knp = &SLIST_NEXT(kn, kn_link);
}
kn = kn0;
}
}
}
free(kq, M_TEMP);
fp->f_data = NULL;
return (0);
}
void
kqueue_wakeup(struct kqueue *kq)
{
if (kq->kq_state & KQ_SLEEP) {
kq->kq_state &= ~KQ_SLEEP;
wakeup(kq);
}
if (kq->kq_state & KQ_SEL) {
kq->kq_state &= ~KQ_SEL;
selwakeup(&kq->kq_sel);
}
KNOTE(&kq->kq_sel.si_note, 0);
}
/*
* walk down a list of knotes, activating them if their event has triggered.
*/
void
knote(struct klist *list, long hint)
{
struct knote *kn;
SLIST_FOREACH(kn, list, kn_selnext)
if (kn->kn_fop->f_event(kn, hint))
KNOTE_ACTIVATE(kn);
}
/*
* remove all knotes from a specified klist
*/
void
knote_remove(struct proc *p, struct klist *list)
{
struct knote *kn;
while ((kn = SLIST_FIRST(list)) != NULL) {
kn->kn_fop->f_detach(kn);
knote_drop(kn, p);
}
}
/*
* remove all knotes referencing a specified fd
*/
void
knote_fdclose(struct proc *p, int fd)
{
struct filedesc *fdp = p->p_fd;
struct klist *list = &fdp->fd_knlist[fd];
knote_remove(p, list);
}
void
knote_attach(struct knote *kn, struct filedesc *fdp)
{
struct klist *list;
int size;
if (! kn->kn_fop->f_isfd) {
if (fdp->fd_knhashmask == 0)
fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP,
M_WAITOK, &fdp->fd_knhashmask);
list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
goto done;
}
if (fdp->fd_knlistsize <= kn->kn_id) {
size = fdp->fd_knlistsize;
while (size <= kn->kn_id)
size += KQEXTENT;
MALLOC(list, struct klist *,
size * sizeof(struct klist *), M_TEMP, M_WAITOK);
bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list,
fdp->fd_knlistsize * sizeof(struct klist *));
bzero((caddr_t)list +
fdp->fd_knlistsize * sizeof(struct klist *),
(size - fdp->fd_knlistsize) * sizeof(struct klist *));
if (fdp->fd_knlist != NULL)
FREE(fdp->fd_knlist, M_TEMP);
fdp->fd_knlistsize = size;
fdp->fd_knlist = list;
}
list = &fdp->fd_knlist[kn->kn_id];
done:
SLIST_INSERT_HEAD(list, kn, kn_link);
kn->kn_status = 0;
}
/*
* should be called at spl == 0, since we don't want to hold spl
* while calling closef and free.
*/
void
knote_drop(struct knote *kn, struct proc *p)
{
struct filedesc *fdp = p->p_fd;
struct klist *list;
if (kn->kn_fop->f_isfd)
list = &fdp->fd_knlist[kn->kn_id];
else
list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
SLIST_REMOVE(list, kn, knote, kn_link);
if (kn->kn_status & KN_QUEUED)
knote_dequeue(kn);
if (kn->kn_fop->f_isfd)
closef(kn->kn_fp, p);
knote_free(kn);
}
void
knote_enqueue(struct knote *kn)
{
struct kqueue *kq = kn->kn_kq;
int s = splhigh();
KASSERT((kn->kn_status & KN_QUEUED) == 0);
TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
kn->kn_status |= KN_QUEUED;
kq->kq_count++;
splx(s);
kqueue_wakeup(kq);
}
void
knote_dequeue(struct knote *kn)
{
struct kqueue *kq = kn->kn_kq;
int s = splhigh();
KASSERT(kn->kn_status & KN_QUEUED);
TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
kn->kn_status &= ~KN_QUEUED;
kq->kq_count--;
splx(s);
}
struct knote *
knote_alloc(void)
{
return (malloc(sizeof (struct knote), M_KNOTE, M_NOWAIT));
}
void
knote_free(struct knote *kn)
{
free(kn, M_KNOTE);
}