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 $
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/unistd.h>
37 #include <sys/fcntl.h>
38 #include <sys/queue.h>
39 #include <sys/event.h>
40 #include <sys/eventvar.h>
41 #include <sys/protosw.h>
42 #include <sys/socket.h>
43 #include <sys/socketvar.h>
45 #include <sys/sysctl.h>
46 #include <sys/sysproto.h>
47 #include <sys/thread.h>
49 #include <sys/signalvar.h>
50 #include <sys/filio.h>
52 #include <sys/spinlock.h>
54 #include <sys/thread2.h>
55 #include <sys/file2.h>
56 #include <sys/mplock2.h>
57 #include <sys/spinlock2.h>
59 #define EVENT_REGISTER 1
60 #define EVENT_PROCESS 2
62 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
64 struct kevent_copyin_args {
65 struct kevent_args *ka;
69 #define KNOTE_CACHE_MAX 64
71 struct knote_cache_list {
72 struct klist knote_cache;
76 static int kqueue_scan(struct kqueue *kq, struct kevent *kevp, int count,
77 struct knote *marker, int closedcounter, int scan_flags);
78 static int kqueue_read(struct file *fp, struct uio *uio,
79 struct ucred *cred, int flags);
80 static int kqueue_write(struct file *fp, struct uio *uio,
81 struct ucred *cred, int flags);
82 static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
83 struct ucred *cred, struct sysmsg *msg);
84 static int kqueue_kqfilter(struct file *fp, struct knote *kn);
85 static int kqueue_stat(struct file *fp, struct stat *st,
87 static int kqueue_close(struct file *fp);
88 static void kqueue_wakeup(struct kqueue *kq);
89 static int filter_attach(struct knote *kn);
90 static int filter_event(struct knote *kn, long hint);
95 static struct fileops kqueueops = {
96 .fo_read = kqueue_read,
97 .fo_write = kqueue_write,
98 .fo_ioctl = kqueue_ioctl,
99 .fo_kqfilter = kqueue_kqfilter,
100 .fo_stat = kqueue_stat,
101 .fo_close = kqueue_close,
102 .fo_shutdown = nofo_shutdown
105 static void knote_attach(struct knote *kn);
106 static void knote_drop(struct knote *kn);
107 static void knote_detach_and_drop(struct knote *kn);
108 static void knote_enqueue(struct knote *kn);
109 static void knote_dequeue(struct knote *kn);
110 static struct knote *knote_alloc(void);
111 static void knote_free(struct knote *kn);
113 static void precise_sleep_intr(systimer_t info, int in_ipi,
114 struct intrframe *frame);
115 static int precise_sleep(void *ident, int flags, const char *wmesg,
118 static void filt_kqdetach(struct knote *kn);
119 static int filt_kqueue(struct knote *kn, long hint);
120 static int filt_procattach(struct knote *kn);
121 static void filt_procdetach(struct knote *kn);
122 static int filt_proc(struct knote *kn, long hint);
123 static int filt_fileattach(struct knote *kn);
124 static void filt_timerexpire(void *knx);
125 static int filt_timerattach(struct knote *kn);
126 static void filt_timerdetach(struct knote *kn);
127 static int filt_timer(struct knote *kn, long hint);
128 static int filt_userattach(struct knote *kn);
129 static void filt_userdetach(struct knote *kn);
130 static int filt_user(struct knote *kn, long hint);
131 static void filt_usertouch(struct knote *kn, struct kevent *kev,
133 static int filt_fsattach(struct knote *kn);
134 static void filt_fsdetach(struct knote *kn);
135 static int filt_fs(struct knote *kn, long hint);
137 static struct filterops file_filtops =
138 { FILTEROP_ISFD | FILTEROP_MPSAFE, filt_fileattach, NULL, NULL };
139 static struct filterops kqread_filtops =
140 { FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, filt_kqdetach, filt_kqueue };
141 static struct filterops proc_filtops =
142 { FILTEROP_MPSAFE, filt_procattach, filt_procdetach, filt_proc };
143 static struct filterops timer_filtops =
144 { FILTEROP_MPSAFE, filt_timerattach, filt_timerdetach, filt_timer };
145 static struct filterops user_filtops =
146 { FILTEROP_MPSAFE, filt_userattach, filt_userdetach, filt_user };
147 static struct filterops fs_filtops =
148 { FILTEROP_MPSAFE, filt_fsattach, filt_fsdetach, filt_fs };
150 static int kq_ncallouts = 0;
151 static int kq_calloutmax = 65536;
152 SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
153 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
154 static int kq_checkloop = 1000000;
155 SYSCTL_INT(_kern, OID_AUTO, kq_checkloop, CTLFLAG_RW,
156 &kq_checkloop, 0, "Maximum number of loops for kqueue scan");
157 static int kq_sleep_threshold = 20000;
158 SYSCTL_INT(_kern, OID_AUTO, kq_sleep_threshold, CTLFLAG_RW,
159 &kq_sleep_threshold, 0, "Minimum sleep duration without busy-looping");
161 #define KNOTE_ACTIVATE(kn) do { \
162 kn->kn_status |= KN_ACTIVE; \
163 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
167 #define KN_HASHSIZE 64 /* XXX should be tunable */
168 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
170 extern struct filterops aio_filtops;
171 extern struct filterops sig_filtops;
174 * Table for for all system-defined filters.
176 static struct filterops *sysfilt_ops[] = {
177 &file_filtops, /* EVFILT_READ */
178 &file_filtops, /* EVFILT_WRITE */
179 &aio_filtops, /* EVFILT_AIO */
180 &file_filtops, /* EVFILT_VNODE */
181 &proc_filtops, /* EVFILT_PROC */
182 &sig_filtops, /* EVFILT_SIGNAL */
183 &timer_filtops, /* EVFILT_TIMER */
184 &file_filtops, /* EVFILT_EXCEPT */
185 &user_filtops, /* EVFILT_USER */
186 &fs_filtops, /* EVFILT_FS */
189 static struct knote_cache_list knote_cache_lists[MAXCPU];
192 * Acquire a knote, return non-zero on success, 0 on failure.
194 * If we cannot acquire the knote we sleep and return 0. The knote
195 * may be stale on return in this case and the caller must restart
196 * whatever loop they are in.
198 * Related kq token must be held.
201 knote_acquire(struct knote *kn)
203 if (kn->kn_status & KN_PROCESSING) {
204 kn->kn_status |= KN_WAITING | KN_REPROCESS;
205 tsleep(kn, 0, "kqepts", hz);
206 /* knote may be stale now */
209 kn->kn_status |= KN_PROCESSING;
214 * Release an acquired knote, clearing KN_PROCESSING and handling any
215 * KN_REPROCESS events.
217 * Caller must be holding the related kq token
219 * Non-zero is returned if the knote is destroyed or detached.
222 knote_release(struct knote *kn)
226 while (kn->kn_status & KN_REPROCESS) {
227 kn->kn_status &= ~KN_REPROCESS;
228 if (kn->kn_status & KN_WAITING) {
229 kn->kn_status &= ~KN_WAITING;
232 if (kn->kn_status & KN_DELETING) {
233 knote_detach_and_drop(kn);
237 if (filter_event(kn, 0))
240 if (kn->kn_status & KN_DETACHED)
244 kn->kn_status &= ~KN_PROCESSING;
245 /* kn should not be accessed anymore */
250 filt_fileattach(struct knote *kn)
252 return (fo_kqfilter(kn->kn_fp, kn));
259 kqueue_kqfilter(struct file *fp, struct knote *kn)
261 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
263 if (kn->kn_filter != EVFILT_READ)
266 kn->kn_fop = &kqread_filtops;
267 knote_insert(&kq->kq_kqinfo.ki_note, kn);
272 filt_kqdetach(struct knote *kn)
274 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
276 knote_remove(&kq->kq_kqinfo.ki_note, kn);
281 filt_kqueue(struct knote *kn, long hint)
283 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
285 kn->kn_data = kq->kq_count;
286 return (kn->kn_data > 0);
290 filt_procattach(struct knote *kn)
296 p = pfind(kn->kn_id);
297 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) {
298 p = zpfind(kn->kn_id);
304 if (!PRISON_CHECK(curthread->td_ucred, p->p_ucred)) {
310 lwkt_gettoken(&p->p_token);
311 kn->kn_ptr.p_proc = p;
312 kn->kn_flags |= EV_CLEAR; /* automatically set */
315 * internal flag indicating registration done by kernel
317 if (kn->kn_flags & EV_FLAG1) {
318 kn->kn_data = kn->kn_sdata; /* ppid */
319 kn->kn_fflags = NOTE_CHILD;
320 kn->kn_flags &= ~EV_FLAG1;
323 knote_insert(&p->p_klist, kn);
326 * Immediately activate any exit notes if the target process is a
327 * zombie. This is necessary to handle the case where the target
328 * process, e.g. a child, dies before the kevent is negistered.
330 if (immediate && filt_proc(kn, NOTE_EXIT))
332 lwkt_reltoken(&p->p_token);
339 * The knote may be attached to a different process, which may exit,
340 * leaving nothing for the knote to be attached to. So when the process
341 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
342 * it will be deleted when read out. However, as part of the knote deletion,
343 * this routine is called, so a check is needed to avoid actually performing
344 * a detach, because the original process does not exist any more.
347 filt_procdetach(struct knote *kn)
351 if (kn->kn_status & KN_DETACHED)
353 p = kn->kn_ptr.p_proc;
354 knote_remove(&p->p_klist, kn);
358 filt_proc(struct knote *kn, long hint)
363 * mask off extra data
365 event = (u_int)hint & NOTE_PCTRLMASK;
368 * if the user is interested in this event, record it.
370 if (kn->kn_sfflags & event)
371 kn->kn_fflags |= event;
374 * Process is gone, so flag the event as finished. Detach the
375 * knote from the process now because the process will be poof,
378 if (event == NOTE_EXIT) {
379 struct proc *p = kn->kn_ptr.p_proc;
380 if ((kn->kn_status & KN_DETACHED) == 0) {
382 knote_remove(&p->p_klist, kn);
383 kn->kn_status |= KN_DETACHED;
384 kn->kn_data = p->p_xstat;
385 kn->kn_ptr.p_proc = NULL;
388 kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
393 * process forked, and user wants to track the new process,
394 * so attach a new knote to it, and immediately report an
395 * event with the parent's pid.
397 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) {
403 * register knote with new process.
405 kev.ident = hint & NOTE_PDATAMASK; /* pid */
406 kev.filter = kn->kn_filter;
407 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
408 kev.fflags = kn->kn_sfflags;
409 kev.data = kn->kn_id; /* parent */
410 kev.udata = kn->kn_kevent.udata; /* preserve udata */
412 error = kqueue_register(kn->kn_kq, &kev, &n);
414 kn->kn_fflags |= NOTE_TRACKERR;
417 return (kn->kn_fflags != 0);
421 filt_timerreset(struct knote *kn)
423 struct callout *calloutp;
427 tv.tv_sec = kn->kn_sdata / 1000;
428 tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
429 tticks = tvtohz_high(&tv);
430 calloutp = (struct callout *)kn->kn_hook;
431 callout_reset(calloutp, tticks, filt_timerexpire, kn);
435 * The callout interlocks with callout_stop() but can still
436 * race a deletion so if KN_DELETING is set we just don't touch
440 filt_timerexpire(void *knx)
442 struct knote *kn = knx;
443 struct kqueue *kq = kn->kn_kq;
445 lwkt_getpooltoken(kq);
448 * Open knote_acquire(), since we can't sleep in callout,
449 * however, we do need to record this expiration.
452 if (kn->kn_status & KN_PROCESSING) {
453 kn->kn_status |= KN_REPROCESS;
454 if ((kn->kn_status & KN_DELETING) == 0 &&
455 (kn->kn_flags & EV_ONESHOT) == 0)
457 lwkt_relpooltoken(kq);
460 KASSERT((kn->kn_status & KN_DELETING) == 0,
461 ("acquire a deleting knote %#x", kn->kn_status));
462 kn->kn_status |= KN_PROCESSING;
465 if ((kn->kn_flags & EV_ONESHOT) == 0)
470 lwkt_relpooltoken(kq);
474 * data contains amount of time to sleep, in milliseconds
477 filt_timerattach(struct knote *kn)
479 struct callout *calloutp;
482 prev_ncallouts = atomic_fetchadd_int(&kq_ncallouts, 1);
483 if (prev_ncallouts >= kq_calloutmax) {
484 atomic_subtract_int(&kq_ncallouts, 1);
489 kn->kn_flags |= EV_CLEAR; /* automatically set */
490 calloutp = kmalloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK);
491 callout_init_mp(calloutp);
492 kn->kn_hook = (caddr_t)calloutp;
499 * This function is called with the knote flagged locked but it is
500 * still possible to race a callout event due to the callback blocking.
503 filt_timerdetach(struct knote *kn)
505 struct callout *calloutp;
507 calloutp = (struct callout *)kn->kn_hook;
508 callout_terminate(calloutp);
510 kfree(calloutp, M_KQUEUE);
511 atomic_subtract_int(&kq_ncallouts, 1);
515 filt_timer(struct knote *kn, long hint)
517 return (kn->kn_data != 0);
524 filt_userattach(struct knote *kn)
529 if (kn->kn_sfflags & NOTE_TRIGGER)
530 kn->kn_ptr.hookid = 1;
532 kn->kn_ptr.hookid = 0;
534 ffctrl = kn->kn_sfflags & NOTE_FFCTRLMASK;
535 kn->kn_sfflags &= NOTE_FFLAGSMASK;
541 kn->kn_fflags &= kn->kn_sfflags;
545 kn->kn_fflags |= kn->kn_sfflags;
549 kn->kn_fflags = kn->kn_sfflags;
553 /* XXX Return error? */
556 /* We just happen to copy this value as well. Undocumented. */
557 kn->kn_data = kn->kn_sdata;
563 filt_userdetach(struct knote *kn)
569 filt_user(struct knote *kn, long hint)
571 return (kn->kn_ptr.hookid);
575 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type)
581 if (kev->fflags & NOTE_TRIGGER)
582 kn->kn_ptr.hookid = 1;
584 ffctrl = kev->fflags & NOTE_FFCTRLMASK;
585 kev->fflags &= NOTE_FFLAGSMASK;
591 kn->kn_fflags &= kev->fflags;
595 kn->kn_fflags |= kev->fflags;
599 kn->kn_fflags = kev->fflags;
603 /* XXX Return error? */
606 /* We just happen to copy this value as well. Undocumented. */
607 kn->kn_data = kev->data;
610 * This is not the correct use of EV_CLEAR in an event
611 * modification, it should have been passed as a NOTE instead.
612 * But we need to maintain compatibility with Apple & FreeBSD.
614 * Note however that EV_CLEAR can still be used when doing
615 * the initial registration of the event and works as expected
616 * (clears the event on reception).
618 if (kev->flags & EV_CLEAR) {
619 kn->kn_ptr.hookid = 0;
621 * Clearing kn->kn_data is fine, since it gets set
622 * every time anyway. We just shouldn't clear
623 * kn->kn_fflags here, since that would limit the
624 * possible uses of this API. NOTE_FFAND or
625 * NOTE_FFCOPY should be used for explicitly clearing
633 *kev = kn->kn_kevent;
634 kev->fflags = kn->kn_fflags;
635 kev->data = kn->kn_data;
636 if (kn->kn_flags & EV_CLEAR) {
637 kn->kn_ptr.hookid = 0;
638 /* kn_data, kn_fflags handled by parent */
643 panic("filt_usertouch() - invalid type (%ld)", type);
651 struct klist fs_klist = SLIST_HEAD_INITIALIZER(&fs_klist);
654 filt_fsattach(struct knote *kn)
656 kn->kn_flags |= EV_CLEAR;
657 knote_insert(&fs_klist, kn);
663 filt_fsdetach(struct knote *kn)
665 knote_remove(&fs_klist, kn);
669 filt_fs(struct knote *kn, long hint)
671 kn->kn_fflags |= hint;
672 return (kn->kn_fflags != 0);
676 * Initialize a kqueue.
678 * NOTE: The lwp/proc code initializes a kqueue for select/poll ops.
681 kqueue_init(struct kqueue *kq, struct filedesc *fdp)
683 bzero(kq, sizeof(*kq));
684 TAILQ_INIT(&kq->kq_knpend);
685 TAILQ_INIT(&kq->kq_knlist);
687 SLIST_INIT(&kq->kq_kqinfo.ki_note);
691 * Terminate a kqueue. Freeing the actual kq itself is left up to the
692 * caller (it might be embedded in a lwp so we don't do it here).
694 * The kq's knlist must be completely eradicated so block on any
698 kqueue_terminate(struct kqueue *kq)
702 lwkt_getpooltoken(kq);
703 while ((kn = TAILQ_FIRST(&kq->kq_knlist)) != NULL) {
704 if (knote_acquire(kn))
705 knote_detach_and_drop(kn);
707 lwkt_relpooltoken(kq);
710 hashdestroy(kq->kq_knhash, M_KQUEUE, kq->kq_knhashmask);
711 kq->kq_knhash = NULL;
712 kq->kq_knhashmask = 0;
720 sys_kqueue(struct kqueue_args *uap)
722 struct thread *td = curthread;
727 error = falloc(td->td_lwp, &fp, &fd);
730 fp->f_flag = FREAD | FWRITE;
731 fp->f_type = DTYPE_KQUEUE;
732 fp->f_ops = &kqueueops;
734 kq = kmalloc(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO);
735 kqueue_init(kq, td->td_proc->p_fd);
738 fsetfd(kq->kq_fdp, fp, fd);
739 uap->sysmsg_result = fd;
745 * Copy 'count' items into the destination list pointed to by uap->eventlist.
748 kevent_copyout(void *arg, struct kevent *kevp, int count, int *res)
750 struct kevent_copyin_args *kap;
753 kap = (struct kevent_copyin_args *)arg;
755 error = copyout(kevp, kap->ka->eventlist, count * sizeof(*kevp));
757 kap->ka->eventlist += count;
767 * Copy at most 'max' items from the list pointed to by kap->changelist,
768 * return number of items in 'events'.
771 kevent_copyin(void *arg, struct kevent *kevp, int max, int *events)
773 struct kevent_copyin_args *kap;
776 kap = (struct kevent_copyin_args *)arg;
778 count = min(kap->ka->nchanges - kap->pchanges, max);
779 error = copyin(kap->ka->changelist, kevp, count * sizeof *kevp);
781 kap->ka->changelist += count;
782 kap->pchanges += count;
793 kern_kevent(struct kqueue *kq, int nevents, int *res, void *uap,
794 k_copyin_fn kevent_copyinfn, k_copyout_fn kevent_copyoutfn,
795 struct timespec *tsp_in, int flags)
798 struct timespec *tsp, ats;
799 int i, n, total, error, nerrors = 0;
802 int limit = kq_checkloop;
805 struct kevent kev[KQ_NEVENTS];
807 struct lwkt_token *tok;
809 if (tsp_in == NULL || tsp_in->tv_sec || tsp_in->tv_nsec)
810 atomic_set_int(&curthread->td_mpflags, TDF_MP_BATCH_DEMARC);
815 closedcounter = kq->kq_fdp->fd_closedcounter;
819 error = kevent_copyinfn(uap, kev, KQ_NEVENTS, &n);
824 for (i = 0; i < n; ++i)
825 kev[i].flags &= ~EV_SYSFLAGS;
826 for (i = 0; i < n; ++i) {
828 error = kqueue_register(kq, &kev[i], &gobbled);
833 * If a registration returns an error we
834 * immediately post the error. The kevent()
835 * call itself will fail with the error if
836 * no space is available for posting.
838 * Such errors normally bypass the timeout/blocking
839 * code. However, if the copyoutfn function refuses
840 * to post the error (see sys_poll()), then we
843 if (error || (kevp->flags & EV_RECEIPT)) {
844 kevp->flags = EV_ERROR;
847 kevent_copyoutfn(uap, kevp, 1, res);
850 } else if (lres != *res) {
861 * Acquire/wait for events - setup timeout
863 * If no timeout specified clean up the run path by clearing the
867 if (tsp->tv_sec || tsp->tv_nsec) {
869 timespecadd(tsp, &ats, tsp); /* tsp = target time */
872 flags &= ~KEVENT_TIMEOUT_PRECISE;
878 * Collect as many events as we can. Sleeping on successive
879 * loops is disabled if copyoutfn has incremented (*res).
881 * The loop stops if an error occurs, all events have been
882 * scanned (the marker has been reached), or fewer than the
883 * maximum number of events is found.
885 * The copyoutfn function does not have to increment (*res) in
886 * order for the loop to continue.
888 * NOTE: doselect() usually passes 0x7FFFFFFF for nevents.
892 marker.kn_filter = EVFILT_MARKER;
893 marker.kn_status = KN_PROCESSING;
895 tok = lwkt_token_pool_lookup(kq);
896 scan_flags = KEVENT_SCAN_INSERT_MARKER;
898 while ((n = nevents - total) > 0) {
903 * Process all received events
904 * Account for all non-spurious events in our total
906 i = kqueue_scan(kq, kev, n, &marker, closedcounter, scan_flags);
907 scan_flags = KEVENT_SCAN_KEEP_MARKER;
910 error = kevent_copyoutfn(uap, kev, i, res);
911 total += *res - lres;
915 if (limit && --limit == 0)
916 panic("kqueue: checkloop failed i=%d", i);
919 * Normally when fewer events are returned than requested
920 * we can stop. However, if only spurious events were
921 * collected the copyout will not bump (*res) and we have
928 * If no events were recorded (no events happened or the events
929 * that did happen were all spurious), block until an event
930 * occurs or the timeout occurs and reload the marker.
932 * If we saturated n (i == n) loop up without sleeping to
933 * continue processing the list.
935 if (i != n && kq->kq_count == 0 && *res == 0) {
942 } else if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) {
946 struct timespec atx = *tsp;
949 timespecsub(&atx, &ats, &atx);
950 if (atx.tv_sec < 0 ||
951 (atx.tv_sec == 0 && atx.tv_nsec <= 0)) {
955 if (flags & KEVENT_TIMEOUT_PRECISE) {
956 if (atx.tv_sec == 0 &&
957 atx.tv_nsec < kq_sleep_threshold) {
958 ustimeout = kq_sleep_threshold /
960 } else if (atx.tv_sec < 60) {
962 atx.tv_sec * 1000000 +
965 ustimeout = 60 * 1000000;
970 } else if (atx.tv_sec > 60 * 60) {
971 timeout = 60 * 60 * hz;
974 timeout = tstohz_high(&atx);
980 if (kq->kq_count == 0) {
982 if (__predict_false(kq->kq_sleep_cnt == 0)) {
984 * Guard against possible wrapping. And
985 * set it to 2, so that kqueue_wakeup()
986 * can wake everyone up.
988 kq->kq_sleep_cnt = 2;
990 if (flags & KEVENT_TIMEOUT_PRECISE) {
991 error = precise_sleep(kq, PCATCH,
992 "kqread", ustimeout);
994 error = tsleep(kq, PCATCH,
998 /* don't restart after signals... */
999 if (error == ERESTART)
1001 if (error == EWOULDBLOCK)
1007 scan_flags = KEVENT_SCAN_RELOAD_MARKER;
1013 * Deal with an edge case where spurious events can cause
1014 * a loop to occur without moving the marker. This can
1015 * prevent kqueue_scan() from picking up new events which
1016 * race us. We must be sure to move the marker for this
1019 * NOTE: We do not want to move the marker if events
1020 * were scanned because normal kqueue operations
1021 * may reactivate events. Moving the marker in
1022 * that case could result in duplicates for the
1026 scan_flags = KEVENT_SCAN_RELOAD_MARKER;
1032 if (scan_flags != KEVENT_SCAN_INSERT_MARKER) {
1034 TAILQ_REMOVE(&kq->kq_knpend, &marker, kn_tqe);
1038 /* Timeouts do not return EWOULDBLOCK. */
1039 if (error == EWOULDBLOCK)
1048 sys_kevent(struct kevent_args *uap)
1050 struct thread *td = curthread;
1051 struct timespec ts, *tsp;
1053 struct file *fp = NULL;
1054 struct kevent_copyin_args *kap, ka;
1058 error = copyin(uap->timeout, &ts, sizeof(ts));
1065 fp = holdfp(td, uap->fd, -1);
1068 if (fp->f_type != DTYPE_KQUEUE) {
1073 kq = (struct kqueue *)fp->f_data;
1079 error = kern_kevent(kq, uap->nevents, &uap->sysmsg_result, kap,
1080 kevent_copyin, kevent_copyout, tsp, 0);
1082 dropfp(td, uap->fd, fp);
1088 * Efficiently load multiple file pointers. This significantly reduces
1089 * threaded overhead. When doing simple polling we can depend on the
1090 * per-thread (fd,fp) cache. With more descriptors, we batch.
1094 floadkevfps(thread_t td, struct filedesc *fdp, struct kevent *kev,
1095 struct file **fp, int climit)
1097 struct filterops *fops;
1100 if (climit <= 2 && td->td_proc && td->td_proc->p_fd == fdp) {
1104 spin_lock_shared(&fdp->fd_spin);
1109 if (kev->filter < 0 &&
1110 kev->filter + EVFILT_SYSCOUNT >= 0) {
1111 fops = sysfilt_ops[~kev->filter];
1112 if (fops->f_flags & FILTEROP_ISFD) {
1114 *fp = holdfp(td, kev->ident, -1);
1116 *fp = holdfp_fdp_locked(fdp,
1126 spin_unlock_shared(&fdp->fd_spin);
1130 * Register up to *countp kev's. Always registers at least 1.
1132 * The number registered is returned in *countp.
1134 * If an error occurs or a kev is flagged EV_RECEIPT, it is
1135 * processed and included in *countp, and processing then
1139 kqueue_register(struct kqueue *kq, struct kevent *kev, int *countp)
1141 struct filedesc *fdp = kq->kq_fdp;
1142 struct klist *list = NULL;
1143 struct filterops *fops;
1144 struct file *fp[KQ_NEVENTS];
1145 struct knote *kn = NULL;
1151 struct knote_cache_list *cache_list;
1155 if (climit > KQ_NEVENTS)
1156 climit = KQ_NEVENTS;
1157 closedcounter = fdp->fd_closedcounter;
1158 floadkevfps(td, fdp, kev, fp, climit);
1160 lwkt_getpooltoken(kq);
1164 * To avoid races, only one thread can register events on this
1167 while (__predict_false(kq->kq_regtd != NULL && kq->kq_regtd != td)) {
1168 kq->kq_state |= KQ_REGWAIT;
1169 tsleep(&kq->kq_regtd, 0, "kqreg", 0);
1171 if (__predict_false(kq->kq_regtd != NULL)) {
1172 /* Recursive calling of kqueue_register() */
1175 /* Owner of the kq_regtd, i.e. td != NULL */
1180 if (kev->filter < 0) {
1181 if (kev->filter + EVFILT_SYSCOUNT < 0) {
1186 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
1190 * filter attach routine is responsible for insuring that
1191 * the identifier can be attached to it.
1198 if (fops->f_flags & FILTEROP_ISFD) {
1199 /* validate descriptor */
1200 if (fp[count] == NULL) {
1207 cache_list = &knote_cache_lists[mycpuid];
1208 if (SLIST_EMPTY(&cache_list->knote_cache)) {
1209 struct knote *new_kn;
1211 new_kn = knote_alloc();
1213 SLIST_INSERT_HEAD(&cache_list->knote_cache, new_kn, kn_link);
1214 cache_list->knote_cache_cnt++;
1218 if (fp[count] != NULL) {
1219 list = &fp[count]->f_klist;
1220 } else if (kq->kq_knhashmask) {
1221 list = &kq->kq_knhash[
1222 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)];
1225 lwkt_getpooltoken(list);
1227 SLIST_FOREACH(kn, list, kn_link) {
1228 if (kn->kn_kq == kq &&
1229 kn->kn_filter == kev->filter &&
1230 kn->kn_id == kev->ident) {
1231 if (knote_acquire(kn) == 0)
1236 lwkt_relpooltoken(list);
1240 * NOTE: At this point if kn is non-NULL we will have acquired
1241 * it and set KN_PROCESSING.
1243 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
1250 * kn now contains the matching knote, or NULL if no match
1252 if (kev->flags & EV_ADD) {
1255 kn = SLIST_FIRST(&cache_list->knote_cache);
1260 SLIST_REMOVE_HEAD(&cache_list->knote_cache,
1262 cache_list->knote_cache_cnt--;
1265 kn->kn_fp = fp[count];
1270 * apply reference count to knote structure, and
1271 * do not release it at the end of this routine.
1273 fp[count] = NULL; /* safety */
1275 kn->kn_sfflags = kev->fflags;
1276 kn->kn_sdata = kev->data;
1279 kn->kn_kevent = *kev;
1282 * KN_PROCESSING prevents the knote from getting
1283 * ripped out from under us while we are trying
1284 * to attach it, in case the attach blocks.
1286 kn->kn_status = KN_PROCESSING;
1288 if ((error = filter_attach(kn)) != 0) {
1289 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1296 * Interlock against close races which either tried
1297 * to remove our knote while we were blocked or missed
1298 * it entirely prior to our attachment. We do not
1299 * want to end up with a knote on a closed descriptor.
1301 if ((fops->f_flags & FILTEROP_ISFD) &&
1302 checkfdclosed(curthread, fdp, kev->ident, kn->kn_fp,
1304 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1308 * The user may change some filter values after the
1309 * initial EV_ADD, but doing so will not reset any
1310 * filter which have already been triggered.
1312 KKASSERT(kn->kn_status & KN_PROCESSING);
1313 if (fops == &user_filtops) {
1314 filt_usertouch(kn, kev, EVENT_REGISTER);
1316 kn->kn_sfflags = kev->fflags;
1317 kn->kn_sdata = kev->data;
1318 kn->kn_kevent.udata = kev->udata;
1323 * Execute the filter event to immediately activate the
1324 * knote if necessary. If reprocessing events are pending
1325 * due to blocking above we do not run the filter here
1326 * but instead let knote_release() do it. Otherwise we
1327 * might run the filter on a deleted event.
1329 if ((kn->kn_status & KN_REPROCESS) == 0) {
1330 if (filter_event(kn, 0))
1333 } else if (kev->flags & EV_DELETE) {
1335 * Delete the existing knote
1337 knote_detach_and_drop(kn);
1343 * Modify an existing event.
1345 * The user may change some filter values after the
1346 * initial EV_ADD, but doing so will not reset any
1347 * filter which have already been triggered.
1349 KKASSERT(kn->kn_status & KN_PROCESSING);
1350 if (fops == &user_filtops) {
1351 filt_usertouch(kn, kev, EVENT_REGISTER);
1353 kn->kn_sfflags = kev->fflags;
1354 kn->kn_sdata = kev->data;
1355 kn->kn_kevent.udata = kev->udata;
1359 * Execute the filter event to immediately activate the
1360 * knote if necessary. If reprocessing events are pending
1361 * due to blocking above we do not run the filter here
1362 * but instead let knote_release() do it. Otherwise we
1363 * might run the filter on a deleted event.
1365 if ((kn->kn_status & KN_REPROCESS) == 0) {
1366 if (filter_event(kn, 0))
1372 * Disablement does not deactivate a knote here.
1374 if ((kev->flags & EV_DISABLE) &&
1375 ((kn->kn_status & KN_DISABLED) == 0)) {
1376 kn->kn_status |= KN_DISABLED;
1380 * Re-enablement may have to immediately enqueue an active knote.
1382 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
1383 kn->kn_status &= ~KN_DISABLED;
1384 if ((kn->kn_status & KN_ACTIVE) &&
1385 ((kn->kn_status & KN_QUEUED) == 0)) {
1391 * Handle any required reprocessing
1394 /* kn may be invalid now */
1397 * Loop control. We stop on errors (above), and also stop after
1398 * processing EV_RECEIPT, so the caller can process it.
1401 if (kev->flags & EV_RECEIPT) {
1406 if (count < climit) {
1407 if (fp[count-1]) /* drop unprocessed fp */
1416 if (td != NULL) { /* Owner of the kq_regtd */
1417 kq->kq_regtd = NULL;
1418 if (__predict_false(kq->kq_state & KQ_REGWAIT)) {
1419 kq->kq_state &= ~KQ_REGWAIT;
1420 wakeup(&kq->kq_regtd);
1423 lwkt_relpooltoken(kq);
1426 * Drop unprocessed file pointers
1429 if (count && fp[count-1])
1431 while (count < climit) {
1440 * Scan the kqueue, return the number of active events placed in kevp up
1443 * Continuous mode events may get recycled, do not continue scanning past
1444 * marker unless no events have been collected.
1447 kqueue_scan(struct kqueue *kq, struct kevent *kevp, int count,
1448 struct knote *marker, int closedcounter, int scan_flags)
1450 struct knote *kn, local_marker;
1451 thread_t td = curthread;
1455 local_marker.kn_filter = EVFILT_MARKER;
1456 local_marker.kn_status = KN_PROCESSING;
1458 lwkt_getpooltoken(kq);
1461 * Adjust marker, insert initial marker, or leave the marker alone.
1463 * Also setup our local_marker.
1465 switch(scan_flags) {
1466 case KEVENT_SCAN_RELOAD_MARKER:
1467 TAILQ_REMOVE(&kq->kq_knpend, marker, kn_tqe);
1469 case KEVENT_SCAN_INSERT_MARKER:
1470 TAILQ_INSERT_TAIL(&kq->kq_knpend, marker, kn_tqe);
1473 TAILQ_INSERT_HEAD(&kq->kq_knpend, &local_marker, kn_tqe);
1479 kn = TAILQ_NEXT(&local_marker, kn_tqe);
1480 if (kn->kn_filter == EVFILT_MARKER) {
1481 /* Marker reached, we are done */
1485 /* Move local marker past some other threads marker */
1486 kn = TAILQ_NEXT(kn, kn_tqe);
1487 TAILQ_REMOVE(&kq->kq_knpend, &local_marker, kn_tqe);
1488 TAILQ_INSERT_BEFORE(kn, &local_marker, kn_tqe);
1493 * We can't skip a knote undergoing processing, otherwise
1494 * we risk not returning it when the user process expects
1495 * it should be returned. Sleep and retry.
1497 if (knote_acquire(kn) == 0)
1501 * Remove the event for processing.
1503 * WARNING! We must leave KN_QUEUED set to prevent the
1504 * event from being KNOTE_ACTIVATE()d while
1505 * the queue state is in limbo, in case we
1508 TAILQ_REMOVE(&kq->kq_knpend, kn, kn_tqe);
1512 * We have to deal with an extremely important race against
1513 * file descriptor close()s here. The file descriptor can
1514 * disappear MPSAFE, and there is a small window of
1515 * opportunity between that and the call to knote_fdclose().
1517 * If we hit that window here while doselect or dopoll is
1518 * trying to delete a spurious event they will not be able
1519 * to match up the event against a knote and will go haywire.
1521 if ((kn->kn_fop->f_flags & FILTEROP_ISFD) &&
1522 checkfdclosed(td, kq->kq_fdp, kn->kn_kevent.ident,
1523 kn->kn_fp, closedcounter)) {
1524 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1527 if (kn->kn_status & KN_DISABLED) {
1529 * If disabled we ensure the event is not queued
1530 * but leave its active bit set. On re-enablement
1531 * the event may be immediately triggered.
1533 kn->kn_status &= ~KN_QUEUED;
1534 } else if ((kn->kn_flags & EV_ONESHOT) == 0 &&
1535 (kn->kn_status & KN_DELETING) == 0 &&
1536 filter_event(kn, 0) == 0) {
1538 * If not running in one-shot mode and the event
1539 * is no longer present we ensure it is removed
1540 * from the queue and ignore it.
1542 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
1547 if (kn->kn_fop == &user_filtops)
1548 filt_usertouch(kn, kevp, EVENT_PROCESS);
1550 *kevp = kn->kn_kevent;
1555 if (kn->kn_flags & EV_ONESHOT) {
1556 kn->kn_status &= ~KN_QUEUED;
1557 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1559 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) {
1560 if (kn->kn_flags & EV_CLEAR) {
1564 if (kn->kn_flags & EV_DISPATCH) {
1565 kn->kn_status |= KN_DISABLED;
1567 kn->kn_status &= ~(KN_QUEUED |
1570 TAILQ_INSERT_TAIL(&kq->kq_knpend, kn, kn_tqe);
1577 * Handle any post-processing states
1581 TAILQ_REMOVE(&kq->kq_knpend, &local_marker, kn_tqe);
1583 lwkt_relpooltoken(kq);
1589 * This could be expanded to call kqueue_scan, if desired.
1594 kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags)
1603 kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags)
1612 kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
1613 struct ucred *cred, struct sysmsg *msg)
1618 kq = (struct kqueue *)fp->f_data;
1619 lwkt_getpooltoken(kq);
1623 kq->kq_state |= KQ_ASYNC;
1625 kq->kq_state &= ~KQ_ASYNC;
1629 error = fsetown(*(int *)data, &kq->kq_sigio);
1635 lwkt_relpooltoken(kq);
1643 kqueue_stat(struct file *fp, struct stat *st, struct ucred *cred)
1645 struct kqueue *kq = (struct kqueue *)fp->f_data;
1647 bzero((void *)st, sizeof(*st));
1648 st->st_size = kq->kq_count;
1649 st->st_blksize = sizeof(struct kevent);
1650 st->st_mode = S_IFIFO;
1658 kqueue_close(struct file *fp)
1660 struct kqueue *kq = (struct kqueue *)fp->f_data;
1662 kqueue_terminate(kq);
1665 funsetown(&kq->kq_sigio);
1667 kfree(kq, M_KQUEUE);
1672 kqueue_wakeup(struct kqueue *kq)
1674 if (kq->kq_sleep_cnt) {
1675 u_int sleep_cnt = kq->kq_sleep_cnt;
1677 kq->kq_sleep_cnt = 0;
1683 KNOTE(&kq->kq_kqinfo.ki_note, 0);
1687 * Calls filterops f_attach function, acquiring mplock if filter is not
1688 * marked as FILTEROP_MPSAFE.
1690 * Caller must be holding the related kq token
1693 filter_attach(struct knote *kn)
1697 if (kn->kn_fop->f_flags & FILTEROP_MPSAFE) {
1698 ret = kn->kn_fop->f_attach(kn);
1701 ret = kn->kn_fop->f_attach(kn);
1708 * Detach the knote and drop it, destroying the knote.
1710 * Calls filterops f_detach function, acquiring mplock if filter is not
1711 * marked as FILTEROP_MPSAFE.
1713 * Caller must be holding the related kq token
1716 knote_detach_and_drop(struct knote *kn)
1718 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1719 if (kn->kn_fop->f_flags & FILTEROP_MPSAFE) {
1720 kn->kn_fop->f_detach(kn);
1723 kn->kn_fop->f_detach(kn);
1730 * Calls filterops f_event function, acquiring mplock if filter is not
1731 * marked as FILTEROP_MPSAFE.
1733 * If the knote is in the middle of being created or deleted we cannot
1734 * safely call the filter op.
1736 * Caller must be holding the related kq token
1739 filter_event(struct knote *kn, long hint)
1743 if (kn->kn_fop->f_flags & FILTEROP_MPSAFE) {
1744 ret = kn->kn_fop->f_event(kn, hint);
1747 ret = kn->kn_fop->f_event(kn, hint);
1754 * Walk down a list of knotes, activating them if their event has triggered.
1756 * If we encounter any knotes which are undergoing processing we just mark
1757 * them for reprocessing and do not try to [re]activate the knote. However,
1758 * if a hint is being passed we have to wait and that makes things a bit
1762 knote(struct klist *list, long hint)
1766 struct knote *kntmp;
1768 lwkt_getpooltoken(list);
1770 SLIST_FOREACH(kn, list, kn_next) {
1772 lwkt_getpooltoken(kq);
1774 /* temporary verification hack */
1775 SLIST_FOREACH(kntmp, list, kn_next) {
1779 if (kn != kntmp || kn->kn_kq != kq) {
1780 lwkt_relpooltoken(kq);
1784 if (kn->kn_status & KN_PROCESSING) {
1786 * Someone else is processing the knote, ask the
1787 * other thread to reprocess it and don't mess
1788 * with it otherwise.
1791 kn->kn_status |= KN_REPROCESS;
1792 lwkt_relpooltoken(kq);
1797 * If the hint is non-zero we have to wait or risk
1798 * losing the state the caller is trying to update.
1800 * XXX This is a real problem, certain process
1801 * and signal filters will bump kn_data for
1802 * already-processed notes more than once if
1803 * we restart the list scan. FIXME.
1805 kn->kn_status |= KN_WAITING | KN_REPROCESS;
1806 tsleep(kn, 0, "knotec", hz);
1807 lwkt_relpooltoken(kq);
1812 * Become the reprocessing master ourselves.
1814 * If hint is non-zero running the event is mandatory
1815 * when not deleting so do it whether reprocessing is
1818 kn->kn_status |= KN_PROCESSING;
1819 if ((kn->kn_status & KN_DELETING) == 0) {
1820 if (filter_event(kn, hint))
1823 if (knote_release(kn)) {
1824 lwkt_relpooltoken(kq);
1827 lwkt_relpooltoken(kq);
1829 lwkt_relpooltoken(list);
1833 * Insert knote at head of klist.
1835 * This function may only be called via a filter function and thus
1836 * kq_token should already be held and marked for processing.
1839 knote_insert(struct klist *klist, struct knote *kn)
1841 lwkt_getpooltoken(klist);
1842 KKASSERT(kn->kn_status & KN_PROCESSING);
1843 SLIST_INSERT_HEAD(klist, kn, kn_next);
1844 lwkt_relpooltoken(klist);
1848 * Remove knote from a klist
1850 * This function may only be called via a filter function and thus
1851 * kq_token should already be held and marked for processing.
1854 knote_remove(struct klist *klist, struct knote *kn)
1856 lwkt_getpooltoken(klist);
1857 KKASSERT(kn->kn_status & KN_PROCESSING);
1858 SLIST_REMOVE(klist, kn, knote, kn_next);
1859 lwkt_relpooltoken(klist);
1863 knote_assume_knotes(struct kqinfo *src, struct kqinfo *dst,
1864 struct filterops *ops, void *hook)
1869 lwkt_getpooltoken(&src->ki_note);
1870 lwkt_getpooltoken(&dst->ki_note);
1871 while ((kn = SLIST_FIRST(&src->ki_note)) != NULL) {
1873 lwkt_getpooltoken(kq);
1874 if (SLIST_FIRST(&src->ki_note) != kn || kn->kn_kq != kq) {
1875 lwkt_relpooltoken(kq);
1878 if (knote_acquire(kn)) {
1879 knote_remove(&src->ki_note, kn);
1882 knote_insert(&dst->ki_note, kn);
1884 /* kn may be invalid now */
1886 lwkt_relpooltoken(kq);
1888 lwkt_relpooltoken(&dst->ki_note);
1889 lwkt_relpooltoken(&src->ki_note);
1893 * Remove all knotes referencing a specified fd
1896 knote_fdclose(struct file *fp, struct filedesc *fdp, int fd)
1900 struct knote *kntmp;
1902 lwkt_getpooltoken(&fp->f_klist);
1904 SLIST_FOREACH(kn, &fp->f_klist, kn_link) {
1905 if (kn->kn_kq->kq_fdp == fdp && kn->kn_id == fd) {
1907 lwkt_getpooltoken(kq);
1909 /* temporary verification hack */
1910 SLIST_FOREACH(kntmp, &fp->f_klist, kn_link) {
1914 if (kn != kntmp || kn->kn_kq->kq_fdp != fdp ||
1915 kn->kn_id != fd || kn->kn_kq != kq) {
1916 lwkt_relpooltoken(kq);
1919 if (knote_acquire(kn))
1920 knote_detach_and_drop(kn);
1921 lwkt_relpooltoken(kq);
1925 lwkt_relpooltoken(&fp->f_klist);
1929 * Low level attach function.
1931 * The knote should already be marked for processing.
1932 * Caller must hold the related kq token.
1935 knote_attach(struct knote *kn)
1938 struct kqueue *kq = kn->kn_kq;
1940 if (kn->kn_fop->f_flags & FILTEROP_ISFD) {
1941 KKASSERT(kn->kn_fp);
1942 list = &kn->kn_fp->f_klist;
1944 if (kq->kq_knhashmask == 0)
1945 kq->kq_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
1946 &kq->kq_knhashmask);
1947 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
1949 lwkt_getpooltoken(list);
1950 SLIST_INSERT_HEAD(list, kn, kn_link);
1951 lwkt_relpooltoken(list);
1952 TAILQ_INSERT_HEAD(&kq->kq_knlist, kn, kn_kqlink);
1956 * Low level drop function.
1958 * The knote should already be marked for processing.
1959 * Caller must hold the related kq token.
1962 knote_drop(struct knote *kn)
1969 if (kn->kn_fop->f_flags & FILTEROP_ISFD)
1970 list = &kn->kn_fp->f_klist;
1972 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
1974 lwkt_getpooltoken(list);
1975 SLIST_REMOVE(list, kn, knote, kn_link);
1976 lwkt_relpooltoken(list);
1977 TAILQ_REMOVE(&kq->kq_knlist, kn, kn_kqlink);
1978 if (kn->kn_status & KN_QUEUED)
1980 if (kn->kn_fop->f_flags & FILTEROP_ISFD) {
1988 * Low level enqueue function.
1990 * The knote should already be marked for processing.
1991 * Caller must be holding the kq token
1994 knote_enqueue(struct knote *kn)
1996 struct kqueue *kq = kn->kn_kq;
1998 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
1999 TAILQ_INSERT_TAIL(&kq->kq_knpend, kn, kn_tqe);
2000 kn->kn_status |= KN_QUEUED;
2004 * Send SIGIO on request (typically set up as a mailbox signal)
2006 if (kq->kq_sigio && (kq->kq_state & KQ_ASYNC) && kq->kq_count == 1)
2007 pgsigio(kq->kq_sigio, SIGIO, 0);
2013 * Low level dequeue function.
2015 * The knote should already be marked for processing.
2016 * Caller must be holding the kq token
2019 knote_dequeue(struct knote *kn)
2021 struct kqueue *kq = kn->kn_kq;
2023 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
2024 TAILQ_REMOVE(&kq->kq_knpend, kn, kn_tqe);
2025 kn->kn_status &= ~KN_QUEUED;
2029 static struct knote *
2032 return kmalloc(sizeof(struct knote), M_KQUEUE, M_WAITOK);
2036 knote_free(struct knote *kn)
2038 struct knote_cache_list *cache_list;
2040 cache_list = &knote_cache_lists[mycpuid];
2041 if (cache_list->knote_cache_cnt < KNOTE_CACHE_MAX) {
2043 SLIST_INSERT_HEAD(&cache_list->knote_cache, kn, kn_link);
2044 cache_list->knote_cache_cnt++;
2048 kfree(kn, M_KQUEUE);
2057 precise_sleep_intr(systimer_t info, int in_ipi, struct intrframe *frame)
2059 struct sleepinfo *si;
2067 precise_sleep(void *ident, int flags, const char *wmesg, int us)
2069 struct systimer info;
2070 struct sleepinfo si = {
2076 tsleep_interlock(ident, flags);
2077 systimer_init_oneshot(&info, precise_sleep_intr, &si, us);
2078 r = tsleep(ident, flags | PINTERLOCKED, wmesg, 0);
2079 systimer_del(&info);