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freebsd-nq/sys/kern/kern_event.c
Alfred Perlstein 13438f6823 When compiling the kernel do not implicitly include filedesc.h from proc.h, 
this was causing filedesc work to be very painful.
In order to make this work split out sigio definitions to thier own header
(sigio.h) which is included from proc.h for the time being.
2003-01-01 01:56:19 +00:00

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/*-
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.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/selinfo.h>
#include <sys/queue.h>
#include <sys/event.h>
#include <sys/eventvar.h>
#include <sys/poll.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/uio.h>
#include <vm/uma.h>
MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
static int kqueue_scan(struct file *fp, int maxevents,
struct kevent *ulistp, const struct timespec *timeout,
struct thread *td);
static void kqueue_wakeup(struct kqueue *kq);
static fo_rdwr_t kqueue_read;
static fo_rdwr_t kqueue_write;
static fo_ioctl_t kqueue_ioctl;
static fo_poll_t kqueue_poll;
static fo_kqfilter_t kqueue_kqfilter;
static fo_stat_t kqueue_stat;
static fo_close_t kqueue_close;
static struct fileops kqueueops = {
kqueue_read,
kqueue_write,
kqueue_ioctl,
kqueue_poll,
kqueue_kqfilter,
kqueue_stat,
kqueue_close
};
static void knote_attach(struct knote *kn, struct filedesc *fdp);
static void knote_drop(struct knote *kn, struct thread *td);
static void knote_enqueue(struct knote *kn);
static void knote_dequeue(struct knote *kn);
static void knote_init(void);
static struct knote *knote_alloc(void);
static void knote_free(struct knote *kn);
static void filt_kqdetach(struct knote *kn);
static int filt_kqueue(struct knote *kn, long hint);
static int filt_procattach(struct knote *kn);
static void filt_procdetach(struct knote *kn);
static int filt_proc(struct knote *kn, long hint);
static int filt_fileattach(struct knote *kn);
static void filt_timerexpire(void *knx);
static int filt_timerattach(struct knote *kn);
static void filt_timerdetach(struct knote *kn);
static int filt_timer(struct knote *kn, long hint);
static struct filterops file_filtops =
{ 1, filt_fileattach, NULL, NULL };
static struct filterops kqread_filtops =
{ 1, NULL, filt_kqdetach, filt_kqueue };
static struct filterops proc_filtops =
{ 0, filt_procattach, filt_procdetach, filt_proc };
static struct filterops timer_filtops =
{ 0, filt_timerattach, filt_timerdetach, filt_timer };
static uma_zone_t knote_zone;
static int kq_ncallouts = 0;
static int kq_calloutmax = (4 * 1024);
SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
&kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
#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))
static int
filt_nullattach(struct knote *kn)
{
return (ENXIO);
};
struct filterops null_filtops =
{ 0, filt_nullattach, NULL, NULL };
extern struct filterops sig_filtops;
/*
* Table for for all system-defined filters.
*/
static struct filterops *sysfilt_ops[] = {
&file_filtops, /* EVFILT_READ */
&file_filtops, /* EVFILT_WRITE */
&null_filtops, /* EVFILT_AIO */
&file_filtops, /* EVFILT_VNODE */
&proc_filtops, /* EVFILT_PROC */
&sig_filtops, /* EVFILT_SIGNAL */
&timer_filtops, /* EVFILT_TIMER */
&file_filtops, /* EVFILT_NETDEV */
};
static int
filt_fileattach(struct knote *kn)
{
return (fo_kqfilter(kn->kn_fp, kn));
}
/*ARGSUSED*/
static 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);
}
static 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*/
static 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);
}
static int
filt_procattach(struct knote *kn)
{
struct proc *p;
int error;
p = pfind(kn->kn_id);
if (p == NULL)
return (ESRCH);
if ((error = p_cansee(curthread, p))) {
PROC_UNLOCK(p);
return (error);
}
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;
}
SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
PROC_UNLOCK(p);
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.
*/
static void
filt_procdetach(struct knote *kn)
{
struct proc *p = kn->kn_ptr.p_proc;
if (kn->kn_status & KN_DETACHED)
return;
PROC_LOCK(p);
SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
PROC_UNLOCK(p);
}
static 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);
}
static void
filt_timerexpire(void *knx)
{
struct knote *kn = knx;
struct callout *calloutp;
struct timeval tv;
int tticks;
kn->kn_data++;
KNOTE_ACTIVATE(kn);
if ((kn->kn_flags & EV_ONESHOT) == 0) {
tv.tv_sec = kn->kn_sdata / 1000;
tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
tticks = tvtohz(&tv);
calloutp = (struct callout *)kn->kn_hook;
callout_reset(calloutp, tticks, filt_timerexpire, kn);
}
}
/*
* data contains amount of time to sleep, in milliseconds
*/
static int
filt_timerattach(struct knote *kn)
{
struct callout *calloutp;
struct timeval tv;
int tticks;
if (kq_ncallouts >= kq_calloutmax)
return (ENOMEM);
kq_ncallouts++;
tv.tv_sec = kn->kn_sdata / 1000;
tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
tticks = tvtohz(&tv);
kn->kn_flags |= EV_CLEAR; /* automatically set */
MALLOC(calloutp, struct callout *, sizeof(*calloutp),
M_KQUEUE, M_WAITOK);
callout_init(calloutp, 0);
callout_reset(calloutp, tticks, filt_timerexpire, kn);
kn->kn_hook = calloutp;
return (0);
}
static void
filt_timerdetach(struct knote *kn)
{
struct callout *calloutp;
calloutp = (struct callout *)kn->kn_hook;
callout_stop(calloutp);
FREE(calloutp, M_KQUEUE);
kq_ncallouts--;
}
static int
filt_timer(struct knote *kn, long hint)
{
return (kn->kn_data != 0);
}
/*
* MPSAFE
*/
int
kqueue(struct thread *td, struct kqueue_args *uap)
{
struct filedesc *fdp;
struct kqueue *kq;
struct file *fp;
int fd, error;
mtx_lock(&Giant);
fdp = td->td_proc->p_fd;
error = falloc(td, &fp, &fd);
if (error)
goto done2;
kq = malloc(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO);
TAILQ_INIT(&kq->kq_head);
FILE_LOCK(fp);
fp->f_flag = FREAD | FWRITE;
fp->f_type = DTYPE_KQUEUE;
fp->f_ops = &kqueueops;
TAILQ_INIT(&kq->kq_head);
fp->f_data = kq;
FILE_UNLOCK(fp);
FILEDESC_LOCK(fdp);
td->td_retval[0] = fd;
if (fdp->fd_knlistsize < 0)
fdp->fd_knlistsize = 0; /* this process has a kq */
FILEDESC_UNLOCK(fdp);
kq->kq_fdp = fdp;
done2:
mtx_unlock(&Giant);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct kevent_args {
int fd;
const struct kevent *changelist;
int nchanges;
struct kevent *eventlist;
int nevents;
const struct timespec *timeout;
};
#endif
/*
* MPSAFE
*/
int
kevent(struct thread *td, struct kevent_args *uap)
{
struct kevent *kevp;
struct kqueue *kq;
struct file *fp;
struct timespec ts;
int i, n, nerrors, error;
if ((error = fget(td, uap->fd, &fp)) != 0)
return (error);
if (fp->f_type != DTYPE_KQUEUE) {
fdrop(fp, td);
return (EBADF);
}
if (uap->timeout != NULL) {
error = copyin(uap->timeout, &ts, sizeof(ts));
if (error)
goto done_nogiant;
uap->timeout = &ts;
}
mtx_lock(&Giant);
kq = (struct kqueue *)fp->f_data;
nerrors = 0;
while (uap->nchanges > 0) {
n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges;
error = copyin(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, td);
if (error) {
if (uap->nevents != 0) {
kevp->flags = EV_ERROR;
kevp->data = error;
(void) copyout(kevp,
uap->eventlist,
sizeof(*kevp));
uap->eventlist++;
uap->nevents--;
nerrors++;
} else {
goto done;
}
}
}
uap->nchanges -= n;
uap->changelist += n;
}
if (nerrors) {
td->td_retval[0] = nerrors;
error = 0;
goto done;
}
error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, td);
done:
mtx_unlock(&Giant);
done_nogiant:
if (fp != NULL)
fdrop(fp, td);
return (error);
}
int
kqueue_add_filteropts(int filt, struct filterops *filtops)
{
if (filt > 0)
panic("filt(%d) > 0", filt);
if (filt + EVFILT_SYSCOUNT < 0)
panic("filt(%d) + EVFILT_SYSCOUNT(%d) == %d < 0",
filt, EVFILT_SYSCOUNT, filt + EVFILT_SYSCOUNT);
if (sysfilt_ops[~filt] != &null_filtops)
panic("sysfilt_ops[~filt(%d)] != &null_filtops", filt);
sysfilt_ops[~filt] = filtops;
return (0);
}
int
kqueue_del_filteropts(int filt)
{
if (filt > 0)
panic("filt(%d) > 0", filt);
if (filt + EVFILT_SYSCOUNT < 0)
panic("filt(%d) + EVFILT_SYSCOUNT(%d) == %d < 0",
filt, EVFILT_SYSCOUNT, filt + EVFILT_SYSCOUNT);
if (sysfilt_ops[~filt] == &null_filtops)
panic("sysfilt_ops[~filt(%d)] != &null_filtops", filt);
sysfilt_ops[~filt] = &null_filtops;
return (0);
}
int
kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td)
{
struct filedesc *fdp = kq->kq_fdp;
struct filterops *fops;
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 */
} else {
/*
* 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);
}
FILEDESC_LOCK(fdp);
if (fops->f_isfd) {
/* validate descriptor */
if ((u_int)kev->ident >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[kev->ident]) == NULL) {
FILEDESC_UNLOCK(fdp);
return (EBADF);
}
fhold(fp);
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;
}
}
FILEDESC_UNLOCK(fdp);
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, td);
goto done;
}
} else {
/*
* The user may change some filter values after the
* initial EV_ADD, but doing so will not reset any
* filter which has 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, td);
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)
fdrop(fp, td);
return (error);
}
static int
kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp,
const struct timespec *tsp, struct thread *td)
{
struct kqueue *kq;
struct kevent *kevp;
struct timeval atv, rtv, ttv;
struct knote *kn, marker;
int s, count, timeout, nkev = 0, error = 0;
FILE_LOCK_ASSERT(fp, MA_NOTOWNED);
kq = (struct kqueue *)fp->f_data;
count = maxevents;
if (count == 0)
goto done;
if (tsp != NULL) {
TIMESPEC_TO_TIMEVAL(&atv, tsp);
if (itimerfix(&atv)) {
error = EINVAL;
goto done;
}
if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
timeout = -1;
else
timeout = atv.tv_sec > 24 * 60 * 60 ?
24 * 60 * 60 * hz : tvtohz(&atv);
getmicrouptime(&rtv);
timevaladd(&atv, &rtv);
} else {
atv.tv_sec = 0;
atv.tv_usec = 0;
timeout = 0;
}
goto start;
retry:
if (atv.tv_sec || atv.tv_usec) {
getmicrouptime(&rtv);
if (timevalcmp(&rtv, &atv, >=))
goto done;
ttv = atv;
timevalsub(&ttv, &rtv);
timeout = ttv.tv_sec > 24 * 60 * 60 ?
24 * 60 * 60 * hz : tvtohz(&ttv);
}
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, td);
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(&kq->kq_kev, 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(&kq->kq_kev, ulistp,
sizeof(struct kevent) * nkev);
td->td_retval[0] = maxevents - count;
return (error);
}
/*
* XXX
* This could be expanded to call kqueue_scan, if desired.
*/
/*ARGSUSED*/
static int
kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
return (ENXIO);
}
/*ARGSUSED*/
static int
kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
return (ENXIO);
}
/*ARGSUSED*/
static int
kqueue_ioctl(struct file *fp, u_long com, void *data,
struct ucred *active_cred, struct thread *td)
{
return (ENOTTY);
}
/*ARGSUSED*/
static int
kqueue_poll(struct file *fp, int events, struct ucred *active_cred,
struct thread *td)
{
struct kqueue *kq;
int revents = 0;
int s = splnet();
kq = (struct kqueue *)fp->f_data;
if (events & (POLLIN | POLLRDNORM)) {
if (kq->kq_count) {
revents |= events & (POLLIN | POLLRDNORM);
} else {
selrecord(td, &kq->kq_sel);
kq->kq_state |= KQ_SEL;
}
}
splx(s);
return (revents);
}
/*ARGSUSED*/
static int
kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
struct thread *td)
{
struct kqueue *kq;
kq = (struct kqueue *)fp->f_data;
bzero((void *)st, sizeof(*st));
st->st_size = kq->kq_count;
st->st_blksize = sizeof(struct kevent);
st->st_mode = S_IFIFO;
return (0);
}
/*ARGSUSED*/
static int
kqueue_close(struct file *fp, struct thread *td)
{
struct kqueue *kq = (struct kqueue *)fp->f_data;
struct filedesc *fdp = td->td_proc->p_fd;
struct knote **knp, *kn, *kn0;
int i;
FILEDESC_LOCK(fdp);
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);
*knp = kn0;
FILE_LOCK(kn->kn_fp);
FILEDESC_UNLOCK(fdp);
fdrop_locked(kn->kn_fp, td);
knote_free(kn);
FILEDESC_LOCK(fdp);
} 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);
*knp = kn0;
/* XXX non-fd release of kn->kn_ptr */
FILEDESC_UNLOCK(fdp);
knote_free(kn);
FILEDESC_LOCK(fdp);
} else {
knp = &SLIST_NEXT(kn, kn_link);
}
kn = kn0;
}
}
}
FILEDESC_UNLOCK(fdp);
free(kq, M_KQUEUE);
fp->f_data = NULL;
return (0);
}
static 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 thread *td, struct klist *list)
{
struct knote *kn;
while ((kn = SLIST_FIRST(list)) != NULL) {
kn->kn_fop->f_detach(kn);
knote_drop(kn, td);
}
}
/*
* remove all knotes referencing a specified fd
*/
void
knote_fdclose(struct thread *td, int fd)
{
struct filedesc *fdp = td->td_proc->p_fd;
struct klist *list;
FILEDESC_LOCK(fdp);
list = &fdp->fd_knlist[fd];
FILEDESC_UNLOCK(fdp);
knote_remove(td, list);
}
static void
knote_attach(struct knote *kn, struct filedesc *fdp)
{
struct klist *list, *oldlist, *tmp_knhash;
u_long tmp_knhashmask;
int size, newsize;
FILEDESC_LOCK(fdp);
if (! kn->kn_fop->f_isfd) {
if (fdp->fd_knhashmask == 0) {
FILEDESC_UNLOCK(fdp);
tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
&tmp_knhashmask);
FILEDESC_LOCK(fdp);
if (fdp->fd_knhashmask == 0) {
fdp->fd_knhash = tmp_knhash;
fdp->fd_knhashmask = tmp_knhashmask;
} else {
FILEDESC_UNLOCK(fdp);
free(tmp_knhash, M_KQUEUE);
FILEDESC_LOCK(fdp);
}
}
list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
goto done;
}
if (fdp->fd_knlistsize <= kn->kn_id) {
retry:
size = fdp->fd_knlistsize;
while (size <= kn->kn_id)
size += KQEXTENT;
FILEDESC_UNLOCK(fdp);
MALLOC(list, struct klist *,
size * sizeof(struct klist *), M_KQUEUE, M_WAITOK);
FILEDESC_LOCK(fdp);
newsize = fdp->fd_knlistsize;
while (newsize <= kn->kn_id)
newsize += KQEXTENT;
if (newsize != size) {
FILEDESC_UNLOCK(fdp);
free(list, M_TEMP);
FILEDESC_LOCK(fdp);
goto retry;
}
bcopy(fdp->fd_knlist, 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)
oldlist = fdp->fd_knlist;
else
oldlist = NULL;
fdp->fd_knlistsize = size;
fdp->fd_knlist = list;
FILEDESC_UNLOCK(fdp);
if (oldlist != NULL)
FREE(oldlist, M_KQUEUE);
FILEDESC_LOCK(fdp);
}
list = &fdp->fd_knlist[kn->kn_id];
done:
FILEDESC_UNLOCK(fdp);
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 fdrop and free.
*/
static void
knote_drop(struct knote *kn, struct thread *td)
{
struct filedesc *fdp = td->td_proc->p_fd;
struct klist *list;
FILEDESC_LOCK(fdp);
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)];
if (kn->kn_fop->f_isfd)
FILE_LOCK(kn->kn_fp);
FILEDESC_UNLOCK(fdp);
SLIST_REMOVE(list, kn, knote, kn_link);
if (kn->kn_status & KN_QUEUED)
knote_dequeue(kn);
if (kn->kn_fop->f_isfd)
fdrop_locked(kn->kn_fp, td);
knote_free(kn);
}
static void
knote_enqueue(struct knote *kn)
{
struct kqueue *kq = kn->kn_kq;
int s = splhigh();
KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
kn->kn_status |= KN_QUEUED;
kq->kq_count++;
splx(s);
kqueue_wakeup(kq);
}
static void
knote_dequeue(struct knote *kn)
{
struct kqueue *kq = kn->kn_kq;
int s = splhigh();
KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
kn->kn_status &= ~KN_QUEUED;
kq->kq_count--;
splx(s);
}
static void
knote_init(void)
{
knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, 0);
}
SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL)
static struct knote *
knote_alloc(void)
{
return ((struct knote *)uma_zalloc(knote_zone, M_WAITOK));
}
static void
knote_free(struct knote *kn)
{
uma_zfree(knote_zone, kn);
}
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