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 MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
64 struct kevent_copyin_args {
65 struct kevent_args *ka;
69 #define KNOTE_CACHE_MAX 8
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);
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.
502 * NOTE: Even though the note is locked via KN_PROCSESING, filt_timerexpire()
503 * can still race us requeue the callout due to potential token cycling
504 * from various blocking conditions. If this situation arises,
505 * callout_stop_sync() will always return non-zero and we can simply
506 * retry the operation.
509 filt_timerdetach(struct knote *kn)
511 struct callout *calloutp;
513 calloutp = (struct callout *)kn->kn_hook;
514 while (callout_stop_sync(calloutp)) {
515 kprintf("debug: kqueue timer race fixed, pid %d %s\n",
516 (curthread->td_proc ? curthread->td_proc->p_pid : 0),
520 kfree(calloutp, M_KQUEUE);
521 atomic_subtract_int(&kq_ncallouts, 1);
525 filt_timer(struct knote *kn, long hint)
527 return (kn->kn_data != 0);
534 filt_userattach(struct knote *kn)
539 if (kn->kn_sfflags & NOTE_TRIGGER)
540 kn->kn_ptr.hookid = 1;
542 kn->kn_ptr.hookid = 0;
544 ffctrl = kn->kn_sfflags & NOTE_FFCTRLMASK;
545 kn->kn_sfflags &= NOTE_FFLAGSMASK;
551 kn->kn_fflags &= kn->kn_sfflags;
555 kn->kn_fflags |= kn->kn_sfflags;
559 kn->kn_fflags = kn->kn_sfflags;
563 /* XXX Return error? */
566 /* We just happen to copy this value as well. Undocumented. */
567 kn->kn_data = kn->kn_sdata;
573 filt_userdetach(struct knote *kn)
579 filt_user(struct knote *kn, long hint)
581 return (kn->kn_ptr.hookid);
585 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type)
591 if (kev->fflags & NOTE_TRIGGER)
592 kn->kn_ptr.hookid = 1;
594 ffctrl = kev->fflags & NOTE_FFCTRLMASK;
595 kev->fflags &= NOTE_FFLAGSMASK;
601 kn->kn_fflags &= kev->fflags;
605 kn->kn_fflags |= kev->fflags;
609 kn->kn_fflags = kev->fflags;
613 /* XXX Return error? */
616 /* We just happen to copy this value as well. Undocumented. */
617 kn->kn_data = kev->data;
620 * This is not the correct use of EV_CLEAR in an event
621 * modification, it should have been passed as a NOTE instead.
622 * But we need to maintain compatibility with Apple & FreeBSD.
624 * Note however that EV_CLEAR can still be used when doing
625 * the initial registration of the event and works as expected
626 * (clears the event on reception).
628 if (kev->flags & EV_CLEAR) {
629 kn->kn_ptr.hookid = 0;
631 * Clearing kn->kn_data is fine, since it gets set
632 * every time anyway. We just shouldn't clear
633 * kn->kn_fflags here, since that would limit the
634 * possible uses of this API. NOTE_FFAND or
635 * NOTE_FFCOPY should be used for explicitly clearing
643 *kev = kn->kn_kevent;
644 kev->fflags = kn->kn_fflags;
645 kev->data = kn->kn_data;
646 if (kn->kn_flags & EV_CLEAR) {
647 kn->kn_ptr.hookid = 0;
648 /* kn_data, kn_fflags handled by parent */
653 panic("filt_usertouch() - invalid type (%ld)", type);
661 struct klist fs_klist = SLIST_HEAD_INITIALIZER(&fs_klist);
664 filt_fsattach(struct knote *kn)
666 kn->kn_flags |= EV_CLEAR;
667 knote_insert(&fs_klist, kn);
673 filt_fsdetach(struct knote *kn)
675 knote_remove(&fs_klist, kn);
679 filt_fs(struct knote *kn, long hint)
681 kn->kn_fflags |= hint;
682 return (kn->kn_fflags != 0);
686 * Initialize a kqueue.
688 * NOTE: The lwp/proc code initializes a kqueue for select/poll ops.
693 kqueue_init(struct kqueue *kq, struct filedesc *fdp)
695 TAILQ_INIT(&kq->kq_knpend);
696 TAILQ_INIT(&kq->kq_knlist);
699 SLIST_INIT(&kq->kq_kqinfo.ki_note);
703 * Terminate a kqueue. Freeing the actual kq itself is left up to the
704 * caller (it might be embedded in a lwp so we don't do it here).
706 * The kq's knlist must be completely eradicated so block on any
710 kqueue_terminate(struct kqueue *kq)
714 lwkt_getpooltoken(kq);
715 while ((kn = TAILQ_FIRST(&kq->kq_knlist)) != NULL) {
716 if (knote_acquire(kn))
717 knote_detach_and_drop(kn);
719 lwkt_relpooltoken(kq);
722 hashdestroy(kq->kq_knhash, M_KQUEUE, kq->kq_knhashmask);
723 kq->kq_knhash = NULL;
724 kq->kq_knhashmask = 0;
732 sys_kqueue(struct kqueue_args *uap)
734 struct thread *td = curthread;
739 error = falloc(td->td_lwp, &fp, &fd);
742 fp->f_flag = FREAD | FWRITE;
743 fp->f_type = DTYPE_KQUEUE;
744 fp->f_ops = &kqueueops;
746 kq = kmalloc(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO);
747 kqueue_init(kq, td->td_proc->p_fd);
750 fsetfd(kq->kq_fdp, fp, fd);
751 uap->sysmsg_result = fd;
757 * Copy 'count' items into the destination list pointed to by uap->eventlist.
760 kevent_copyout(void *arg, struct kevent *kevp, int count, int *res)
762 struct kevent_copyin_args *kap;
765 kap = (struct kevent_copyin_args *)arg;
767 error = copyout(kevp, kap->ka->eventlist, count * sizeof(*kevp));
769 kap->ka->eventlist += count;
779 * Copy at most 'max' items from the list pointed to by kap->changelist,
780 * return number of items in 'events'.
783 kevent_copyin(void *arg, struct kevent *kevp, int max, int *events)
785 struct kevent_copyin_args *kap;
788 kap = (struct kevent_copyin_args *)arg;
790 count = min(kap->ka->nchanges - kap->pchanges, max);
791 error = copyin(kap->ka->changelist, kevp, count * sizeof *kevp);
793 kap->ka->changelist += count;
794 kap->pchanges += count;
805 kern_kevent(struct kqueue *kq, int nevents, int *res, void *uap,
806 k_copyin_fn kevent_copyinfn, k_copyout_fn kevent_copyoutfn,
807 struct timespec *tsp_in, int flags)
810 struct timespec *tsp, ats;
811 int i, n, total, error, nerrors = 0;
814 int limit = kq_checkloop;
816 struct kevent kev[KQ_NEVENTS];
818 struct lwkt_token *tok;
820 if (tsp_in == NULL || tsp_in->tv_sec || tsp_in->tv_nsec)
821 atomic_set_int(&curthread->td_mpflags, TDF_MP_BATCH_DEMARC);
826 closedcounter = kq->kq_fdp->fd_closedcounter;
830 error = kevent_copyinfn(uap, kev, KQ_NEVENTS, &n);
835 for (i = 0; i < n; ++i)
836 kev[i].flags &= ~EV_SYSFLAGS;
837 for (i = 0; i < n; ++i) {
839 error = kqueue_register(kq, &kev[i], &gobbled);
844 * If a registration returns an error we
845 * immediately post the error. The kevent()
846 * call itself will fail with the error if
847 * no space is available for posting.
849 * Such errors normally bypass the timeout/blocking
850 * code. However, if the copyoutfn function refuses
851 * to post the error (see sys_poll()), then we
854 if (error || (kevp->flags & EV_RECEIPT)) {
855 kevp->flags = EV_ERROR;
858 kevent_copyoutfn(uap, kevp, 1, res);
861 } else if (lres != *res) {
872 * Acquire/wait for events - setup timeout
875 if (tsp->tv_sec || tsp->tv_nsec) {
877 timespecadd(tsp, &ats); /* tsp = target time */
884 * Collect as many events as we can. Sleeping on successive
885 * loops is disabled if copyoutfn has incremented (*res).
887 * The loop stops if an error occurs, all events have been
888 * scanned (the marker has been reached), or fewer than the
889 * maximum number of events is found.
891 * The copyoutfn function does not have to increment (*res) in
892 * order for the loop to continue.
894 * NOTE: doselect() usually passes 0x7FFFFFFF for nevents.
898 marker.kn_filter = EVFILT_MARKER;
899 marker.kn_status = KN_PROCESSING;
900 tok = lwkt_token_pool_lookup(kq);
902 TAILQ_INSERT_TAIL(&kq->kq_knpend, &marker, kn_tqe);
904 while ((n = nevents - total) > 0) {
909 * If no events are pending sleep until timeout (if any)
910 * or an event occurs.
912 * After the sleep completes the marker is moved to the
913 * end of the list, making any received events available
916 if (kq->kq_count == 0 && *res == 0) {
917 int timeout, ustimeout = 0;
921 } else if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) {
925 struct timespec atx = *tsp;
928 timespecsub(&atx, &ats);
929 if (atx.tv_sec < 0) {
933 timeout = atx.tv_sec > 24 * 60 * 60 ?
937 if (flags & KEVENT_TIMEOUT_PRECISE &&
939 if (atx.tv_sec == 0 &&
940 atx.tv_nsec < kq_sleep_threshold) {
941 DELAY(atx.tv_nsec / 1000);
944 } else if (atx.tv_sec < 2000) {
945 ustimeout = atx.tv_sec *
946 1000000 + atx.tv_nsec/1000;
948 ustimeout = 2000000000;
954 if (kq->kq_count == 0) {
956 if (__predict_false(kq->kq_sleep_cnt == 0)) {
958 * Guard against possible wrapping. And
959 * set it to 2, so that kqueue_wakeup()
960 * can wake everyone up.
962 kq->kq_sleep_cnt = 2;
964 if ((flags & KEVENT_TIMEOUT_PRECISE) &&
966 error = precise_sleep(kq, PCATCH,
967 "kqread", ustimeout);
969 error = tsleep(kq, PCATCH, "kqread",
973 /* don't restart after signals... */
974 if (error == ERESTART)
981 TAILQ_REMOVE(&kq->kq_knpend, &marker, kn_tqe);
982 TAILQ_INSERT_TAIL(&kq->kq_knpend, &marker,
989 * Process all received events
990 * Account for all non-spurious events in our total
992 i = kqueue_scan(kq, kev, n, &marker, closedcounter);
995 error = kevent_copyoutfn(uap, kev, i, res);
996 total += *res - lres;
1000 if (limit && --limit == 0)
1001 panic("kqueue: checkloop failed i=%d", i);
1004 * Normally when fewer events are returned than requested
1005 * we can stop. However, if only spurious events were
1006 * collected the copyout will not bump (*res) and we have
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
1027 TAILQ_REMOVE(&kq->kq_knpend, &marker, kn_tqe);
1028 TAILQ_INSERT_TAIL(&kq->kq_knpend, &marker, kn_tqe);
1033 TAILQ_REMOVE(&kq->kq_knpend, &marker, kn_tqe);
1036 /* Timeouts do not return EWOULDBLOCK. */
1037 if (error == EWOULDBLOCK)
1046 sys_kevent(struct kevent_args *uap)
1048 struct thread *td = curthread;
1049 struct timespec ts, *tsp;
1051 struct file *fp = NULL;
1052 struct kevent_copyin_args *kap, ka;
1056 error = copyin(uap->timeout, &ts, sizeof(ts));
1063 fp = holdfp(td, uap->fd, -1);
1066 if (fp->f_type != DTYPE_KQUEUE) {
1071 kq = (struct kqueue *)fp->f_data;
1077 error = kern_kevent(kq, uap->nevents, &uap->sysmsg_result, kap,
1078 kevent_copyin, kevent_copyout, tsp, 0);
1080 dropfp(td, uap->fd, fp);
1086 * Efficiently load multiple file pointers. This significantly reduces
1087 * threaded overhead. When doing simple polling we can depend on the
1088 * per-thread (fd,fp) cache. With more descriptors, we batch.
1092 floadkevfps(thread_t td, struct filedesc *fdp, struct kevent *kev,
1093 struct file **fp, int climit)
1095 struct filterops *fops;
1098 if (climit <= 2 && td->td_proc && td->td_proc->p_fd == fdp) {
1102 spin_lock_shared(&fdp->fd_spin);
1107 if (kev->filter < 0 &&
1108 kev->filter + EVFILT_SYSCOUNT >= 0) {
1109 fops = sysfilt_ops[~kev->filter];
1110 if (fops->f_flags & FILTEROP_ISFD) {
1112 *fp = holdfp(td, kev->ident, -1);
1114 *fp = holdfp_fdp_locked(fdp,
1124 spin_unlock_shared(&fdp->fd_spin);
1128 * Register up to *countp kev's. Always registers at least 1.
1130 * The number registered is returned in *countp.
1132 * If an error occurs or a kev is flagged EV_RECEIPT, it is
1133 * processed and included in *countp, and processing then
1137 kqueue_register(struct kqueue *kq, struct kevent *kev, int *countp)
1139 struct filedesc *fdp = kq->kq_fdp;
1140 struct klist *list = NULL;
1141 struct filterops *fops;
1142 struct file *fp[KQ_NEVENTS];
1143 struct knote *kn = NULL;
1149 struct knote_cache_list *cache_list;
1153 if (climit > KQ_NEVENTS)
1154 climit = KQ_NEVENTS;
1155 closedcounter = fdp->fd_closedcounter;
1156 floadkevfps(td, fdp, kev, fp, climit);
1158 lwkt_getpooltoken(kq);
1162 * To avoid races, only one thread can register events on this
1165 while (__predict_false(kq->kq_regtd != NULL && kq->kq_regtd != td)) {
1166 kq->kq_state |= KQ_REGWAIT;
1167 tsleep(&kq->kq_regtd, 0, "kqreg", 0);
1169 if (__predict_false(kq->kq_regtd != NULL)) {
1170 /* Recursive calling of kqueue_register() */
1173 /* Owner of the kq_regtd, i.e. td != NULL */
1178 if (kev->filter < 0) {
1179 if (kev->filter + EVFILT_SYSCOUNT < 0) {
1184 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
1188 * filter attach routine is responsible for insuring that
1189 * the identifier can be attached to it.
1196 if (fops->f_flags & FILTEROP_ISFD) {
1197 /* validate descriptor */
1198 if (fp[count] == NULL) {
1205 cache_list = &knote_cache_lists[mycpuid];
1206 if (SLIST_EMPTY(&cache_list->knote_cache)) {
1207 struct knote *new_kn;
1209 new_kn = knote_alloc();
1211 SLIST_INSERT_HEAD(&cache_list->knote_cache, new_kn, kn_link);
1212 cache_list->knote_cache_cnt++;
1216 if (fp[count] != NULL) {
1217 list = &fp[count]->f_klist;
1218 } else if (kq->kq_knhashmask) {
1219 list = &kq->kq_knhash[
1220 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)];
1223 lwkt_getpooltoken(list);
1225 SLIST_FOREACH(kn, list, kn_link) {
1226 if (kn->kn_kq == kq &&
1227 kn->kn_filter == kev->filter &&
1228 kn->kn_id == kev->ident) {
1229 if (knote_acquire(kn) == 0)
1234 lwkt_relpooltoken(list);
1238 * NOTE: At this point if kn is non-NULL we will have acquired
1239 * it and set KN_PROCESSING.
1241 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
1248 * kn now contains the matching knote, or NULL if no match
1250 if (kev->flags & EV_ADD) {
1253 kn = SLIST_FIRST(&cache_list->knote_cache);
1258 SLIST_REMOVE_HEAD(&cache_list->knote_cache,
1260 cache_list->knote_cache_cnt--;
1263 kn->kn_fp = fp[count];
1268 * apply reference count to knote structure, and
1269 * do not release it at the end of this routine.
1271 fp[count] = NULL; /* safety */
1273 kn->kn_sfflags = kev->fflags;
1274 kn->kn_sdata = kev->data;
1277 kn->kn_kevent = *kev;
1280 * KN_PROCESSING prevents the knote from getting
1281 * ripped out from under us while we are trying
1282 * to attach it, in case the attach blocks.
1284 kn->kn_status = KN_PROCESSING;
1286 if ((error = filter_attach(kn)) != 0) {
1287 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1294 * Interlock against close races which either tried
1295 * to remove our knote while we were blocked or missed
1296 * it entirely prior to our attachment. We do not
1297 * want to end up with a knote on a closed descriptor.
1299 if ((fops->f_flags & FILTEROP_ISFD) &&
1300 checkfdclosed(curthread, fdp, kev->ident, kn->kn_fp,
1302 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1306 * The user may change some filter values after the
1307 * initial EV_ADD, but doing so will not reset any
1308 * filter which have already been triggered.
1310 KKASSERT(kn->kn_status & KN_PROCESSING);
1311 if (fops == &user_filtops) {
1312 filt_usertouch(kn, kev, EVENT_REGISTER);
1314 kn->kn_sfflags = kev->fflags;
1315 kn->kn_sdata = kev->data;
1316 kn->kn_kevent.udata = kev->udata;
1321 * Execute the filter event to immediately activate the
1322 * knote if necessary. If reprocessing events are pending
1323 * due to blocking above we do not run the filter here
1324 * but instead let knote_release() do it. Otherwise we
1325 * might run the filter on a deleted event.
1327 if ((kn->kn_status & KN_REPROCESS) == 0) {
1328 if (filter_event(kn, 0))
1331 } else if (kev->flags & EV_DELETE) {
1333 * Delete the existing knote
1335 knote_detach_and_drop(kn);
1341 * Modify an existing event.
1343 * The user may change some filter values after the
1344 * initial EV_ADD, but doing so will not reset any
1345 * filter which have already been triggered.
1347 KKASSERT(kn->kn_status & KN_PROCESSING);
1348 if (fops == &user_filtops) {
1349 filt_usertouch(kn, kev, EVENT_REGISTER);
1351 kn->kn_sfflags = kev->fflags;
1352 kn->kn_sdata = kev->data;
1353 kn->kn_kevent.udata = kev->udata;
1357 * Execute the filter event to immediately activate the
1358 * knote if necessary. If reprocessing events are pending
1359 * due to blocking above we do not run the filter here
1360 * but instead let knote_release() do it. Otherwise we
1361 * might run the filter on a deleted event.
1363 if ((kn->kn_status & KN_REPROCESS) == 0) {
1364 if (filter_event(kn, 0))
1370 * Disablement does not deactivate a knote here.
1372 if ((kev->flags & EV_DISABLE) &&
1373 ((kn->kn_status & KN_DISABLED) == 0)) {
1374 kn->kn_status |= KN_DISABLED;
1378 * Re-enablement may have to immediately enqueue an active knote.
1380 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
1381 kn->kn_status &= ~KN_DISABLED;
1382 if ((kn->kn_status & KN_ACTIVE) &&
1383 ((kn->kn_status & KN_QUEUED) == 0)) {
1389 * Handle any required reprocessing
1392 /* kn may be invalid now */
1395 * Loop control. We stop on errors (above), and also stop after
1396 * processing EV_RECEIPT, so the caller can process it.
1399 if (kev->flags & EV_RECEIPT) {
1404 if (count < climit) {
1405 if (fp[count-1]) /* drop unprocessed fp */
1414 if (td != NULL) { /* Owner of the kq_regtd */
1415 kq->kq_regtd = NULL;
1416 if (__predict_false(kq->kq_state & KQ_REGWAIT)) {
1417 kq->kq_state &= ~KQ_REGWAIT;
1418 wakeup(&kq->kq_regtd);
1421 lwkt_relpooltoken(kq);
1424 * Drop unprocessed file pointers
1427 if (count && fp[count-1])
1429 while (count < climit) {
1438 * Scan the kqueue, return the number of active events placed in kevp up
1441 * Continuous mode events may get recycled, do not continue scanning past
1442 * marker unless no events have been collected.
1445 kqueue_scan(struct kqueue *kq, struct kevent *kevp, int count,
1446 struct knote *marker, int closedcounter)
1448 struct knote *kn, local_marker;
1449 thread_t td = curthread;
1453 local_marker.kn_filter = EVFILT_MARKER;
1454 local_marker.kn_status = KN_PROCESSING;
1456 lwkt_getpooltoken(kq);
1461 TAILQ_INSERT_HEAD(&kq->kq_knpend, &local_marker, kn_tqe);
1463 kn = TAILQ_NEXT(&local_marker, kn_tqe);
1464 if (kn->kn_filter == EVFILT_MARKER) {
1465 /* Marker reached, we are done */
1469 /* Move local marker past some other threads marker */
1470 kn = TAILQ_NEXT(kn, kn_tqe);
1471 TAILQ_REMOVE(&kq->kq_knpend, &local_marker, kn_tqe);
1472 TAILQ_INSERT_BEFORE(kn, &local_marker, kn_tqe);
1477 * We can't skip a knote undergoing processing, otherwise
1478 * we risk not returning it when the user process expects
1479 * it should be returned. Sleep and retry.
1481 if (knote_acquire(kn) == 0)
1485 * Remove the event for processing.
1487 * WARNING! We must leave KN_QUEUED set to prevent the
1488 * event from being KNOTE_ACTIVATE()d while
1489 * the queue state is in limbo, in case we
1492 TAILQ_REMOVE(&kq->kq_knpend, kn, kn_tqe);
1496 * We have to deal with an extremely important race against
1497 * file descriptor close()s here. The file descriptor can
1498 * disappear MPSAFE, and there is a small window of
1499 * opportunity between that and the call to knote_fdclose().
1501 * If we hit that window here while doselect or dopoll is
1502 * trying to delete a spurious event they will not be able
1503 * to match up the event against a knote and will go haywire.
1505 if ((kn->kn_fop->f_flags & FILTEROP_ISFD) &&
1506 checkfdclosed(td, kq->kq_fdp, kn->kn_kevent.ident,
1507 kn->kn_fp, closedcounter)) {
1508 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1511 if (kn->kn_status & KN_DISABLED) {
1513 * If disabled we ensure the event is not queued
1514 * but leave its active bit set. On re-enablement
1515 * the event may be immediately triggered.
1517 kn->kn_status &= ~KN_QUEUED;
1518 } else if ((kn->kn_flags & EV_ONESHOT) == 0 &&
1519 (kn->kn_status & KN_DELETING) == 0 &&
1520 filter_event(kn, 0) == 0) {
1522 * If not running in one-shot mode and the event
1523 * is no longer present we ensure it is removed
1524 * from the queue and ignore it.
1526 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
1531 if (kn->kn_fop == &user_filtops)
1532 filt_usertouch(kn, kevp, EVENT_PROCESS);
1534 *kevp = kn->kn_kevent;
1539 if (kn->kn_flags & EV_ONESHOT) {
1540 kn->kn_status &= ~KN_QUEUED;
1541 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1543 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) {
1544 if (kn->kn_flags & EV_CLEAR) {
1548 if (kn->kn_flags & EV_DISPATCH) {
1549 kn->kn_status |= KN_DISABLED;
1551 kn->kn_status &= ~(KN_QUEUED |
1554 TAILQ_INSERT_TAIL(&kq->kq_knpend, kn, kn_tqe);
1561 * Handle any post-processing states
1565 TAILQ_REMOVE(&kq->kq_knpend, &local_marker, kn_tqe);
1567 lwkt_relpooltoken(kq);
1573 * This could be expanded to call kqueue_scan, if desired.
1578 kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags)
1587 kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags)
1596 kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
1597 struct ucred *cred, struct sysmsg *msg)
1602 kq = (struct kqueue *)fp->f_data;
1603 lwkt_getpooltoken(kq);
1607 kq->kq_state |= KQ_ASYNC;
1609 kq->kq_state &= ~KQ_ASYNC;
1613 error = fsetown(*(int *)data, &kq->kq_sigio);
1619 lwkt_relpooltoken(kq);
1627 kqueue_stat(struct file *fp, struct stat *st, struct ucred *cred)
1629 struct kqueue *kq = (struct kqueue *)fp->f_data;
1631 bzero((void *)st, sizeof(*st));
1632 st->st_size = kq->kq_count;
1633 st->st_blksize = sizeof(struct kevent);
1634 st->st_mode = S_IFIFO;
1642 kqueue_close(struct file *fp)
1644 struct kqueue *kq = (struct kqueue *)fp->f_data;
1646 kqueue_terminate(kq);
1649 funsetown(&kq->kq_sigio);
1651 kfree(kq, M_KQUEUE);
1656 kqueue_wakeup(struct kqueue *kq)
1658 if (kq->kq_sleep_cnt) {
1659 u_int sleep_cnt = kq->kq_sleep_cnt;
1661 kq->kq_sleep_cnt = 0;
1667 KNOTE(&kq->kq_kqinfo.ki_note, 0);
1671 * Calls filterops f_attach function, acquiring mplock if filter is not
1672 * marked as FILTEROP_MPSAFE.
1674 * Caller must be holding the related kq token
1677 filter_attach(struct knote *kn)
1681 if (kn->kn_fop->f_flags & FILTEROP_MPSAFE) {
1682 ret = kn->kn_fop->f_attach(kn);
1685 ret = kn->kn_fop->f_attach(kn);
1692 * Detach the knote and drop it, destroying the knote.
1694 * Calls filterops f_detach function, acquiring mplock if filter is not
1695 * marked as FILTEROP_MPSAFE.
1697 * Caller must be holding the related kq token
1700 knote_detach_and_drop(struct knote *kn)
1702 kn->kn_status |= KN_DELETING | KN_REPROCESS;
1703 if (kn->kn_fop->f_flags & FILTEROP_MPSAFE) {
1704 kn->kn_fop->f_detach(kn);
1707 kn->kn_fop->f_detach(kn);
1714 * Calls filterops f_event function, acquiring mplock if filter is not
1715 * marked as FILTEROP_MPSAFE.
1717 * If the knote is in the middle of being created or deleted we cannot
1718 * safely call the filter op.
1720 * Caller must be holding the related kq token
1723 filter_event(struct knote *kn, long hint)
1727 if (kn->kn_fop->f_flags & FILTEROP_MPSAFE) {
1728 ret = kn->kn_fop->f_event(kn, hint);
1731 ret = kn->kn_fop->f_event(kn, hint);
1738 * Walk down a list of knotes, activating them if their event has triggered.
1740 * If we encounter any knotes which are undergoing processing we just mark
1741 * them for reprocessing and do not try to [re]activate the knote. However,
1742 * if a hint is being passed we have to wait and that makes things a bit
1746 knote(struct klist *list, long hint)
1750 struct knote *kntmp;
1752 lwkt_getpooltoken(list);
1754 SLIST_FOREACH(kn, list, kn_next) {
1756 lwkt_getpooltoken(kq);
1758 /* temporary verification hack */
1759 SLIST_FOREACH(kntmp, list, kn_next) {
1763 if (kn != kntmp || kn->kn_kq != kq) {
1764 lwkt_relpooltoken(kq);
1768 if (kn->kn_status & KN_PROCESSING) {
1770 * Someone else is processing the knote, ask the
1771 * other thread to reprocess it and don't mess
1772 * with it otherwise.
1775 kn->kn_status |= KN_REPROCESS;
1776 lwkt_relpooltoken(kq);
1781 * If the hint is non-zero we have to wait or risk
1782 * losing the state the caller is trying to update.
1784 * XXX This is a real problem, certain process
1785 * and signal filters will bump kn_data for
1786 * already-processed notes more than once if
1787 * we restart the list scan. FIXME.
1789 kn->kn_status |= KN_WAITING | KN_REPROCESS;
1790 tsleep(kn, 0, "knotec", hz);
1791 lwkt_relpooltoken(kq);
1796 * Become the reprocessing master ourselves.
1798 * If hint is non-zero running the event is mandatory
1799 * when not deleting so do it whether reprocessing is
1802 kn->kn_status |= KN_PROCESSING;
1803 if ((kn->kn_status & KN_DELETING) == 0) {
1804 if (filter_event(kn, hint))
1807 if (knote_release(kn)) {
1808 lwkt_relpooltoken(kq);
1811 lwkt_relpooltoken(kq);
1813 lwkt_relpooltoken(list);
1817 * Insert knote at head of klist.
1819 * This function may only be called via a filter function and thus
1820 * kq_token should already be held and marked for processing.
1823 knote_insert(struct klist *klist, struct knote *kn)
1825 lwkt_getpooltoken(klist);
1826 KKASSERT(kn->kn_status & KN_PROCESSING);
1827 SLIST_INSERT_HEAD(klist, kn, kn_next);
1828 lwkt_relpooltoken(klist);
1832 * Remove knote from a klist
1834 * This function may only be called via a filter function and thus
1835 * kq_token should already be held and marked for processing.
1838 knote_remove(struct klist *klist, struct knote *kn)
1840 lwkt_getpooltoken(klist);
1841 KKASSERT(kn->kn_status & KN_PROCESSING);
1842 SLIST_REMOVE(klist, kn, knote, kn_next);
1843 lwkt_relpooltoken(klist);
1847 knote_assume_knotes(struct kqinfo *src, struct kqinfo *dst,
1848 struct filterops *ops, void *hook)
1853 lwkt_getpooltoken(&src->ki_note);
1854 lwkt_getpooltoken(&dst->ki_note);
1855 while ((kn = SLIST_FIRST(&src->ki_note)) != NULL) {
1857 lwkt_getpooltoken(kq);
1858 if (SLIST_FIRST(&src->ki_note) != kn || kn->kn_kq != kq) {
1859 lwkt_relpooltoken(kq);
1862 if (knote_acquire(kn)) {
1863 knote_remove(&src->ki_note, kn);
1866 knote_insert(&dst->ki_note, kn);
1868 /* kn may be invalid now */
1870 lwkt_relpooltoken(kq);
1872 lwkt_relpooltoken(&dst->ki_note);
1873 lwkt_relpooltoken(&src->ki_note);
1877 * Remove all knotes referencing a specified fd
1880 knote_fdclose(struct file *fp, struct filedesc *fdp, int fd)
1884 struct knote *kntmp;
1886 lwkt_getpooltoken(&fp->f_klist);
1888 SLIST_FOREACH(kn, &fp->f_klist, kn_link) {
1889 if (kn->kn_kq->kq_fdp == fdp && kn->kn_id == fd) {
1891 lwkt_getpooltoken(kq);
1893 /* temporary verification hack */
1894 SLIST_FOREACH(kntmp, &fp->f_klist, kn_link) {
1898 if (kn != kntmp || kn->kn_kq->kq_fdp != fdp ||
1899 kn->kn_id != fd || kn->kn_kq != kq) {
1900 lwkt_relpooltoken(kq);
1903 if (knote_acquire(kn))
1904 knote_detach_and_drop(kn);
1905 lwkt_relpooltoken(kq);
1909 lwkt_relpooltoken(&fp->f_klist);
1913 * Low level attach function.
1915 * The knote should already be marked for processing.
1916 * Caller must hold the related kq token.
1919 knote_attach(struct knote *kn)
1922 struct kqueue *kq = kn->kn_kq;
1924 if (kn->kn_fop->f_flags & FILTEROP_ISFD) {
1925 KKASSERT(kn->kn_fp);
1926 list = &kn->kn_fp->f_klist;
1928 if (kq->kq_knhashmask == 0)
1929 kq->kq_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
1930 &kq->kq_knhashmask);
1931 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
1933 lwkt_getpooltoken(list);
1934 SLIST_INSERT_HEAD(list, kn, kn_link);
1935 lwkt_relpooltoken(list);
1936 TAILQ_INSERT_HEAD(&kq->kq_knlist, kn, kn_kqlink);
1940 * Low level drop function.
1942 * The knote should already be marked for processing.
1943 * Caller must hold the related kq token.
1946 knote_drop(struct knote *kn)
1953 if (kn->kn_fop->f_flags & FILTEROP_ISFD)
1954 list = &kn->kn_fp->f_klist;
1956 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
1958 lwkt_getpooltoken(list);
1959 SLIST_REMOVE(list, kn, knote, kn_link);
1960 lwkt_relpooltoken(list);
1961 TAILQ_REMOVE(&kq->kq_knlist, kn, kn_kqlink);
1962 if (kn->kn_status & KN_QUEUED)
1964 if (kn->kn_fop->f_flags & FILTEROP_ISFD) {
1972 * Low level enqueue function.
1974 * The knote should already be marked for processing.
1975 * Caller must be holding the kq token
1978 knote_enqueue(struct knote *kn)
1980 struct kqueue *kq = kn->kn_kq;
1982 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
1983 TAILQ_INSERT_TAIL(&kq->kq_knpend, kn, kn_tqe);
1984 kn->kn_status |= KN_QUEUED;
1988 * Send SIGIO on request (typically set up as a mailbox signal)
1990 if (kq->kq_sigio && (kq->kq_state & KQ_ASYNC) && kq->kq_count == 1)
1991 pgsigio(kq->kq_sigio, SIGIO, 0);
1997 * Low level dequeue function.
1999 * The knote should already be marked for processing.
2000 * Caller must be holding the kq token
2003 knote_dequeue(struct knote *kn)
2005 struct kqueue *kq = kn->kn_kq;
2007 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
2008 TAILQ_REMOVE(&kq->kq_knpend, kn, kn_tqe);
2009 kn->kn_status &= ~KN_QUEUED;
2013 static struct knote *
2016 return kmalloc(sizeof(struct knote), M_KQUEUE, M_WAITOK);
2020 knote_free(struct knote *kn)
2022 struct knote_cache_list *cache_list;
2024 cache_list = &knote_cache_lists[mycpuid];
2025 if (cache_list->knote_cache_cnt < KNOTE_CACHE_MAX) {
2027 SLIST_INSERT_HEAD(&cache_list->knote_cache, kn, kn_link);
2028 cache_list->knote_cache_cnt++;
2032 kfree(kn, M_KQUEUE);
2041 precise_sleep_intr(systimer_t info, int in_ipi, struct intrframe *frame)
2043 struct sleepinfo *si;
2051 precise_sleep(void *ident, int flags, const char *wmesg, int us)
2053 struct systimer info;
2054 struct sleepinfo si = {
2060 tsleep_interlock(ident, flags);
2061 systimer_init_oneshot(&info, precise_sleep_intr, &si,
2063 r = tsleep(ident, flags | PINTERLOCKED, wmesg, 0);
2064 systimer_del(&info);