2 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/kern/kern_event.c,v 1.2.2.10 2004/04/04 07:03:14 cperciva Exp $
27 * $DragonFly: src/sys/kern/kern_event.c,v 1.33 2007/02/03 17:05:57 corecode Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/unistd.h>
38 #include <sys/fcntl.h>
39 #include <sys/select.h>
40 #include <sys/queue.h>
41 #include <sys/event.h>
42 #include <sys/eventvar.h>
44 #include <sys/protosw.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
48 #include <sys/sysctl.h>
49 #include <sys/sysproto.h>
51 #include <sys/thread2.h>
52 #include <sys/signalvar.h>
53 #include <sys/filio.h>
54 #include <sys/file2.h>
56 #include <vm/vm_zone.h>
58 MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
60 static int kqueue_scan(struct file *fp, int maxevents,
61 struct kevent *ulistp, const struct timespec *timeout,
62 struct thread *td, int *res);
63 static int kqueue_read(struct file *fp, struct uio *uio,
64 struct ucred *cred, int flags);
65 static int kqueue_write(struct file *fp, struct uio *uio,
66 struct ucred *cred, int flags);
67 static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
69 static int kqueue_poll(struct file *fp, int events, struct ucred *cred);
70 static int kqueue_kqfilter(struct file *fp, struct knote *kn);
71 static int kqueue_stat(struct file *fp, struct stat *st,
73 static int kqueue_close(struct file *fp);
74 static void kqueue_wakeup(struct kqueue *kq);
79 static struct fileops kqueueops = {
80 .fo_read = kqueue_read,
81 .fo_write = kqueue_write,
82 .fo_ioctl = kqueue_ioctl,
83 .fo_poll = kqueue_poll,
84 .fo_kqfilter = kqueue_kqfilter,
85 .fo_stat = kqueue_stat,
86 .fo_close = kqueue_close,
87 .fo_shutdown = nofo_shutdown
90 static void knote_attach(struct knote *kn, struct filedesc *fdp);
91 static void knote_drop(struct knote *kn, struct thread *td);
92 static void knote_enqueue(struct knote *kn);
93 static void knote_dequeue(struct knote *kn);
94 static void knote_init(void);
95 static struct knote *knote_alloc(void);
96 static void knote_free(struct knote *kn);
98 static void filt_kqdetach(struct knote *kn);
99 static int filt_kqueue(struct knote *kn, long hint);
100 static int filt_procattach(struct knote *kn);
101 static void filt_procdetach(struct knote *kn);
102 static int filt_proc(struct knote *kn, long hint);
103 static int filt_fileattach(struct knote *kn);
104 static void filt_timerexpire(void *knx);
105 static int filt_timerattach(struct knote *kn);
106 static void filt_timerdetach(struct knote *kn);
107 static int filt_timer(struct knote *kn, long hint);
109 static struct filterops file_filtops =
110 { 1, filt_fileattach, NULL, NULL };
111 static struct filterops kqread_filtops =
112 { 1, NULL, filt_kqdetach, filt_kqueue };
113 static struct filterops proc_filtops =
114 { 0, filt_procattach, filt_procdetach, filt_proc };
115 static struct filterops timer_filtops =
116 { 0, filt_timerattach, filt_timerdetach, filt_timer };
118 static vm_zone_t knote_zone;
119 static int kq_ncallouts = 0;
120 static int kq_calloutmax = (4 * 1024);
121 SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
122 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
124 #define KNOTE_ACTIVATE(kn) do { \
125 kn->kn_status |= KN_ACTIVE; \
126 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
130 #define KN_HASHSIZE 64 /* XXX should be tunable */
131 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
133 extern struct filterops aio_filtops;
134 extern struct filterops sig_filtops;
137 * Table for for all system-defined filters.
139 static struct filterops *sysfilt_ops[] = {
140 &file_filtops, /* EVFILT_READ */
141 &file_filtops, /* EVFILT_WRITE */
142 &aio_filtops, /* EVFILT_AIO */
143 &file_filtops, /* EVFILT_VNODE */
144 &proc_filtops, /* EVFILT_PROC */
145 &sig_filtops, /* EVFILT_SIGNAL */
146 &timer_filtops, /* EVFILT_TIMER */
150 filt_fileattach(struct knote *kn)
152 return (fo_kqfilter(kn->kn_fp, kn));
156 * MPALMOSTSAFE - acquires mplock
159 kqueue_kqfilter(struct file *fp, struct knote *kn)
161 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
164 if (kn->kn_filter != EVFILT_READ) {
169 kn->kn_fop = &kqread_filtops;
170 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext);
176 filt_kqdetach(struct knote *kn)
178 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
180 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext);
185 filt_kqueue(struct knote *kn, long hint)
187 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
189 kn->kn_data = kq->kq_count;
190 return (kn->kn_data > 0);
194 filt_procattach(struct knote *kn)
200 p = pfind(kn->kn_id);
201 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) {
202 p = zpfind(kn->kn_id);
207 if (! PRISON_CHECK(curproc->p_ucred, p->p_ucred))
210 kn->kn_ptr.p_proc = p;
211 kn->kn_flags |= EV_CLEAR; /* automatically set */
214 * internal flag indicating registration done by kernel
216 if (kn->kn_flags & EV_FLAG1) {
217 kn->kn_data = kn->kn_sdata; /* ppid */
218 kn->kn_fflags = NOTE_CHILD;
219 kn->kn_flags &= ~EV_FLAG1;
222 /* XXX lock the proc here while adding to the list? */
223 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
226 * Immediately activate any exit notes if the target process is a
227 * zombie. This is necessary to handle the case where the target
228 * process, e.g. a child, dies before the kevent is registered.
230 if (immediate && filt_proc(kn, NOTE_EXIT))
237 * The knote may be attached to a different process, which may exit,
238 * leaving nothing for the knote to be attached to. So when the process
239 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
240 * it will be deleted when read out. However, as part of the knote deletion,
241 * this routine is called, so a check is needed to avoid actually performing
242 * a detach, because the original process does not exist any more.
245 filt_procdetach(struct knote *kn)
247 struct proc *p = kn->kn_ptr.p_proc;
249 if (kn->kn_status & KN_DETACHED)
252 /* XXX locking? this might modify another process. */
253 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
257 filt_proc(struct knote *kn, long hint)
262 * mask off extra data
264 event = (u_int)hint & NOTE_PCTRLMASK;
267 * if the user is interested in this event, record it.
269 if (kn->kn_sfflags & event)
270 kn->kn_fflags |= event;
273 * process is gone, so flag the event as finished.
275 if (event == NOTE_EXIT) {
276 kn->kn_status |= KN_DETACHED;
277 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
282 * process forked, and user wants to track the new process,
283 * so attach a new knote to it, and immediately report an
284 * event with the parent's pid.
286 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) {
291 * register knote with new process.
293 kev.ident = hint & NOTE_PDATAMASK; /* pid */
294 kev.filter = kn->kn_filter;
295 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
296 kev.fflags = kn->kn_sfflags;
297 kev.data = kn->kn_id; /* parent */
298 kev.udata = kn->kn_kevent.udata; /* preserve udata */
299 error = kqueue_register(kn->kn_kq, &kev, NULL);
301 kn->kn_fflags |= NOTE_TRACKERR;
304 return (kn->kn_fflags != 0);
308 filt_timerexpire(void *knx)
310 struct knote *kn = knx;
311 struct callout *calloutp;
318 if ((kn->kn_flags & EV_ONESHOT) == 0) {
319 tv.tv_sec = kn->kn_sdata / 1000;
320 tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
321 tticks = tvtohz_high(&tv);
322 calloutp = (struct callout *)kn->kn_hook;
323 callout_reset(calloutp, tticks, filt_timerexpire, kn);
328 * data contains amount of time to sleep, in milliseconds
331 filt_timerattach(struct knote *kn)
333 struct callout *calloutp;
337 if (kq_ncallouts >= kq_calloutmax)
341 tv.tv_sec = kn->kn_sdata / 1000;
342 tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
343 tticks = tvtohz_high(&tv);
345 kn->kn_flags |= EV_CLEAR; /* automatically set */
346 MALLOC(calloutp, struct callout *, sizeof(*calloutp),
348 callout_init(calloutp);
349 kn->kn_hook = (caddr_t)calloutp;
350 callout_reset(calloutp, tticks, filt_timerexpire, kn);
356 filt_timerdetach(struct knote *kn)
358 struct callout *calloutp;
360 calloutp = (struct callout *)kn->kn_hook;
361 callout_stop(calloutp);
362 FREE(calloutp, M_KQUEUE);
367 filt_timer(struct knote *kn, long hint)
370 return (kn->kn_data != 0);
374 sys_kqueue(struct kqueue_args *uap)
376 struct proc *p = curproc;
377 struct filedesc *fdp = p->p_fd;
382 error = falloc(p, &fp, &fd);
385 fp->f_flag = FREAD | FWRITE;
386 fp->f_type = DTYPE_KQUEUE;
387 fp->f_ops = &kqueueops;
389 kq = kmalloc(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO);
390 TAILQ_INIT(&kq->kq_head);
395 uap->sysmsg_result = fd;
401 sys_kevent(struct kevent_args *uap)
403 struct thread *td = curthread;
404 struct proc *p = td->td_proc;
407 struct file *fp = NULL;
409 int i, n, nerrors, error;
413 fp = holdfp(p->p_fd, uap->fd, -1);
416 if (fp->f_type != DTYPE_KQUEUE) {
421 if (uap->timeout != NULL) {
422 error = copyin(uap->timeout, &ts, sizeof(ts));
428 kq = (struct kqueue *)fp->f_data;
431 while (uap->nchanges > 0) {
432 n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges;
433 error = copyin(uap->changelist, kq->kq_kev,
434 n * sizeof(struct kevent));
437 for (i = 0; i < n; i++) {
438 kevp = &kq->kq_kev[i];
439 kevp->flags &= ~EV_SYSFLAGS;
440 error = kqueue_register(kq, kevp, td);
442 if (uap->nevents != 0) {
443 kevp->flags = EV_ERROR;
445 (void) copyout((caddr_t)kevp,
446 (caddr_t)uap->eventlist,
457 uap->changelist += n;
460 uap->sysmsg_result = nerrors;
465 error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, td, &uap->sysmsg_result);
473 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td)
475 struct filedesc *fdp = kq->kq_fdp;
476 struct filterops *fops;
477 struct file *fp = NULL;
478 struct knote *kn = NULL;
481 if (kev->filter < 0) {
482 if (kev->filter + EVFILT_SYSCOUNT < 0)
484 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
488 * filter attach routine is responsible for insuring that
489 * the identifier can be attached to it.
491 kprintf("unknown filter: %d\n", kev->filter);
496 /* validate descriptor */
497 fp = holdfp(fdp, kev->ident, -1);
501 if (kev->ident < fdp->fd_knlistsize) {
502 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link)
503 if (kq == kn->kn_kq &&
504 kev->filter == kn->kn_filter)
508 if (fdp->fd_knhashmask != 0) {
511 list = &fdp->fd_knhash[
512 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)];
513 SLIST_FOREACH(kn, list, kn_link)
514 if (kev->ident == kn->kn_id &&
516 kev->filter == kn->kn_filter)
521 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
527 * kn now contains the matching knote, or NULL if no match
529 if (kev->flags & EV_ADD) {
542 * apply reference count to knote structure, and
543 * do not release it at the end of this routine.
547 kn->kn_sfflags = kev->fflags;
548 kn->kn_sdata = kev->data;
551 kn->kn_kevent = *kev;
553 knote_attach(kn, fdp);
554 if ((error = fops->f_attach(kn)) != 0) {
560 * The user may change some filter values after the
561 * initial EV_ADD, but doing so will not reset any
562 * filter which have already been triggered.
564 kn->kn_sfflags = kev->fflags;
565 kn->kn_sdata = kev->data;
566 kn->kn_kevent.udata = kev->udata;
570 if (kn->kn_fop->f_event(kn, 0))
573 } else if (kev->flags & EV_DELETE) {
574 kn->kn_fop->f_detach(kn);
579 if ((kev->flags & EV_DISABLE) &&
580 ((kn->kn_status & KN_DISABLED) == 0)) {
582 kn->kn_status |= KN_DISABLED;
586 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
588 kn->kn_status &= ~KN_DISABLED;
589 if ((kn->kn_status & KN_ACTIVE) &&
590 ((kn->kn_status & KN_QUEUED) == 0))
602 kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp,
603 const struct timespec *tsp, struct thread *td, int *res)
605 struct kqueue *kq = (struct kqueue *)fp->f_data;
607 struct timeval atv, rtv, ttv;
608 struct knote *kn, marker;
609 int count, timeout, nkev = 0, error = 0;
616 TIMESPEC_TO_TIMEVAL(&atv, tsp);
617 if (itimerfix(&atv)) {
621 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
624 timeout = atv.tv_sec > 24 * 60 * 60 ?
625 24 * 60 * 60 * hz : tvtohz_high(&atv);
626 getmicrouptime(&rtv);
627 timevaladd(&atv, &rtv);
636 if (atv.tv_sec || atv.tv_usec) {
637 getmicrouptime(&rtv);
638 if (timevalcmp(&rtv, &atv, >=))
641 timevalsub(&ttv, &rtv);
642 timeout = ttv.tv_sec > 24 * 60 * 60 ?
643 24 * 60 * 60 * hz : tvtohz_high(&ttv);
649 if (kq->kq_count == 0) {
653 kq->kq_state |= KQ_SLEEP;
654 error = tsleep(kq, PCATCH, "kqread", timeout);
659 /* don't restart after signals... */
660 if (error == ERESTART)
662 else if (error == EWOULDBLOCK)
667 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe);
669 kn = TAILQ_FIRST(&kq->kq_head);
670 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
673 if (count == maxevents)
677 if (kn->kn_status & KN_DISABLED) {
678 kn->kn_status &= ~KN_QUEUED;
682 if ((kn->kn_flags & EV_ONESHOT) == 0 &&
683 kn->kn_fop->f_event(kn, 0) == 0) {
684 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
688 *kevp = kn->kn_kevent;
691 if (kn->kn_flags & EV_ONESHOT) {
692 kn->kn_status &= ~KN_QUEUED;
695 kn->kn_fop->f_detach(kn);
698 } else if (kn->kn_flags & EV_CLEAR) {
701 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
704 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
707 if (nkev == KQ_NEVENTS) {
709 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
710 sizeof(struct kevent) * nkev);
719 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe);
723 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
724 sizeof(struct kevent) * nkev);
725 *res = maxevents - count;
731 * This could be expanded to call kqueue_scan, if desired.
736 kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags)
745 kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags)
754 kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct ucred *cred)
760 kq = (struct kqueue *)fp->f_data;
765 kq->kq_state |= KQ_ASYNC;
767 kq->kq_state &= ~KQ_ASYNC;
771 error = fsetown(*(int *)data, &kq->kq_sigio);
782 * MPALMOSTSAFE - acquires mplock
785 kqueue_poll(struct file *fp, int events, struct ucred *cred)
787 struct kqueue *kq = (struct kqueue *)fp->f_data;
792 if (events & (POLLIN | POLLRDNORM)) {
794 revents |= events & (POLLIN | POLLRDNORM);
796 selrecord(curthread, &kq->kq_sel);
797 kq->kq_state |= KQ_SEL;
809 kqueue_stat(struct file *fp, struct stat *st, struct ucred *cred)
811 struct kqueue *kq = (struct kqueue *)fp->f_data;
813 bzero((void *)st, sizeof(*st));
814 st->st_size = kq->kq_count;
815 st->st_blksize = sizeof(struct kevent);
816 st->st_mode = S_IFIFO;
821 * MPALMOSTSAFE - acquires mplock
824 kqueue_close(struct file *fp)
826 struct thread *td = curthread;
827 struct proc *p = td->td_proc;
828 struct kqueue *kq = (struct kqueue *)fp->f_data;
829 struct filedesc *fdp;
830 struct knote **knp, *kn, *kn0;
836 for (i = 0; i < fdp->fd_knlistsize; i++) {
837 knp = &SLIST_FIRST(&fdp->fd_knlist[i]);
840 kn0 = SLIST_NEXT(kn, kn_link);
841 if (kq == kn->kn_kq) {
842 kn->kn_fop->f_detach(kn);
847 knp = &SLIST_NEXT(kn, kn_link);
852 if (fdp->fd_knhashmask != 0) {
853 for (i = 0; i < fdp->fd_knhashmask + 1; i++) {
854 knp = &SLIST_FIRST(&fdp->fd_knhash[i]);
857 kn0 = SLIST_NEXT(kn, kn_link);
858 if (kq == kn->kn_kq) {
859 kn->kn_fop->f_detach(kn);
860 /* XXX non-fd release of kn->kn_ptr */
864 knp = &SLIST_NEXT(kn, kn_link);
871 funsetown(kq->kq_sigio);
879 kqueue_wakeup(struct kqueue *kq)
881 if (kq->kq_state & KQ_SLEEP) {
882 kq->kq_state &= ~KQ_SLEEP;
885 if (kq->kq_state & KQ_SEL) {
886 kq->kq_state &= ~KQ_SEL;
887 selwakeup(&kq->kq_sel);
889 KNOTE(&kq->kq_sel.si_note, 0);
893 * walk down a list of knotes, activating them if their event has triggered.
896 knote(struct klist *list, long hint)
900 SLIST_FOREACH(kn, list, kn_selnext)
901 if (kn->kn_fop->f_event(kn, hint))
906 * remove all knotes from a specified klist
909 knote_remove(struct thread *td, struct klist *list)
913 while ((kn = SLIST_FIRST(list)) != NULL) {
914 kn->kn_fop->f_detach(kn);
920 * remove all knotes referencing a specified fd
923 knote_fdclose(struct proc *p, int fd)
925 struct filedesc *fdp = p->p_fd;
926 struct klist *list = &fdp->fd_knlist[fd];
927 /* Take any thread of p */
928 struct thread *td = FIRST_LWP_IN_PROC(p)->lwp_thread;
930 knote_remove(td, list);
934 knote_attach(struct knote *kn, struct filedesc *fdp)
939 if (! kn->kn_fop->f_isfd) {
940 if (fdp->fd_knhashmask == 0)
941 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
942 &fdp->fd_knhashmask);
943 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
947 if (fdp->fd_knlistsize <= kn->kn_id) {
948 size = fdp->fd_knlistsize;
949 while (size <= kn->kn_id)
951 MALLOC(list, struct klist *,
952 size * sizeof(struct klist *), M_KQUEUE, M_WAITOK);
953 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list,
954 fdp->fd_knlistsize * sizeof(struct klist *));
955 bzero((caddr_t)list +
956 fdp->fd_knlistsize * sizeof(struct klist *),
957 (size - fdp->fd_knlistsize) * sizeof(struct klist *));
958 if (fdp->fd_knlist != NULL)
959 FREE(fdp->fd_knlist, M_KQUEUE);
960 fdp->fd_knlistsize = size;
961 fdp->fd_knlist = list;
963 list = &fdp->fd_knlist[kn->kn_id];
965 SLIST_INSERT_HEAD(list, kn, kn_link);
970 * should be called outside of a critical section, since we don't want to
971 * hold a critical section while calling fdrop and free.
974 knote_drop(struct knote *kn, struct thread *td)
976 struct filedesc *fdp;
979 KKASSERT(td->td_proc);
980 fdp = td->td_proc->p_fd;
981 if (kn->kn_fop->f_isfd)
982 list = &fdp->fd_knlist[kn->kn_id];
984 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
986 SLIST_REMOVE(list, kn, knote, kn_link);
987 if (kn->kn_status & KN_QUEUED)
989 if (kn->kn_fop->f_isfd)
996 knote_enqueue(struct knote *kn)
998 struct kqueue *kq = kn->kn_kq;
1001 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
1003 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
1004 kn->kn_status |= KN_QUEUED;
1008 * Send SIGIO on request (typically set up as a mailbox signal)
1010 if (kq->kq_sigio && (kq->kq_state & KQ_ASYNC) && kq->kq_count == 1)
1011 pgsigio(kq->kq_sigio, SIGIO, 0);
1017 knote_dequeue(struct knote *kn)
1019 struct kqueue *kq = kn->kn_kq;
1021 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
1024 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
1025 kn->kn_status &= ~KN_QUEUED;
1033 knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1);
1035 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL)
1037 static struct knote *
1040 return ((struct knote *)zalloc(knote_zone));
1044 knote_free(struct knote *kn)
1046 zfree(knote_zone, kn);