/* $OpenBSD: kern_event.c,v 1.28 2006/12/01 07:17:25 camield Exp $ */ /*- * Copyright (c) 1999,2000,2001 Jonathan Lemon * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/sys/kern/kern_event.c,v 1.22 2001/02/23 20:32:42 jlemon Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include int kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, const struct timespec *timeout, struct proc *p, int *retval); int kqueue_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred); int kqueue_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred); int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p); int kqueue_poll(struct file *fp, int events, struct proc *p); int kqueue_kqfilter(struct file *fp, struct knote *kn); int kqueue_stat(struct file *fp, struct stat *st, struct proc *p); int kqueue_close(struct file *fp, struct proc *p); void kqueue_wakeup(struct kqueue *kq); struct fileops kqueueops = { kqueue_read, kqueue_write, kqueue_ioctl, kqueue_poll, kqueue_kqfilter, kqueue_stat, kqueue_close }; void knote_attach(struct knote *kn, struct filedesc *fdp); void knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp); void knote_enqueue(struct knote *kn); void knote_dequeue(struct knote *kn); #define knote_alloc() ((struct knote *)pool_get(&knote_pool, PR_WAITOK)) #define knote_free(kn) pool_put(&knote_pool, (kn)) void filt_kqdetach(struct knote *kn); int filt_kqueue(struct knote *kn, long hint); int filt_procattach(struct knote *kn); void filt_procdetach(struct knote *kn); int filt_proc(struct knote *kn, long hint); int filt_fileattach(struct knote *kn); struct filterops kqread_filtops = { 1, NULL, filt_kqdetach, filt_kqueue }; struct filterops proc_filtops = { 0, filt_procattach, filt_procdetach, filt_proc }; struct filterops file_filtops = { 1, filt_fileattach, NULL, NULL }; struct pool knote_pool; struct pool kqueue_pool; #define KNOTE_ACTIVATE(kn) do { \ kn->kn_status |= KN_ACTIVE; \ if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ knote_enqueue(kn); \ } while(0) #define KN_HASHSIZE 64 /* XXX should be tunable */ #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) extern struct filterops sig_filtops; #ifdef notyet extern struct filterops aio_filtops; #endif /* * Table for for all system-defined filters. */ struct filterops *sysfilt_ops[] = { &file_filtops, /* EVFILT_READ */ &file_filtops, /* EVFILT_WRITE */ NULL, /*&aio_filtops,*/ /* EVFILT_AIO */ &file_filtops, /* EVFILT_VNODE */ &proc_filtops, /* EVFILT_PROC */ &sig_filtops, /* EVFILT_SIGNAL */ }; void kqueue_init(void); void kqueue_init(void) { pool_init(&kqueue_pool, sizeof(struct kqueue), 0, 0, 0, "kqueuepl", &pool_allocator_nointr); pool_init(&knote_pool, sizeof(struct knote), 0, 0, 0, "knotepl", &pool_allocator_nointr); } int filt_fileattach(struct knote *kn) { struct file *fp = kn->kn_fp; return ((*fp->f_ops->fo_kqfilter)(fp, kn)); } int kqueue_kqfilter(struct file *fp, struct knote *kn) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; if (kn->kn_filter != EVFILT_READ) return (1); kn->kn_fop = &kqread_filtops; SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); return (0); } void filt_kqdetach(struct knote *kn) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); } /*ARGSUSED*/ int filt_kqueue(struct knote *kn, long hint) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; kn->kn_data = kq->kq_count; return (kn->kn_data > 0); } int filt_procattach(struct knote *kn) { struct proc *p; p = pfind(kn->kn_id); if (p == NULL) return (ESRCH); /* * Fail if it's not owned by you, or the last exec gave us * setuid/setgid privs (unless you're root). */ if ((p->p_cred->p_ruid != curproc->p_cred->p_ruid || (p->p_flag & P_SUGID)) && suser(curproc, 0) != 0) return (EACCES); kn->kn_ptr.p_proc = p; kn->kn_flags |= EV_CLEAR; /* automatically set */ /* * internal flag indicating registration done by kernel */ if (kn->kn_flags & EV_FLAG1) { kn->kn_data = kn->kn_sdata; /* ppid */ kn->kn_fflags = NOTE_CHILD; kn->kn_flags &= ~EV_FLAG1; } /* XXX lock the proc here while adding to the list? */ SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); return (0); } /* * The knote may be attached to a different process, which may exit, * leaving nothing for the knote to be attached to. So when the process * exits, the knote is marked as DETACHED and also flagged as ONESHOT so * it will be deleted when read out. However, as part of the knote deletion, * this routine is called, so a check is needed to avoid actually performing * a detach, because the original process does not exist any more. */ void filt_procdetach(struct knote *kn) { struct proc *p = kn->kn_ptr.p_proc; if (kn->kn_status & KN_DETACHED) return; /* XXX locking? this might modify another process. */ SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); } int filt_proc(struct knote *kn, long hint) { u_int event; /* * mask off extra data */ event = (u_int)hint & NOTE_PCTRLMASK; /* * if the user is interested in this event, record it. */ if (kn->kn_sfflags & event) kn->kn_fflags |= event; /* * process is gone, so flag the event as finished. */ if (event == NOTE_EXIT) { kn->kn_status |= KN_DETACHED; kn->kn_flags |= (EV_EOF | EV_ONESHOT); return (1); } /* * process forked, and user wants to track the new process, * so attach a new knote to it, and immediately report an * event with the parent's pid. */ if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { struct kevent kev; int error; /* * register knote with new process. */ kev.ident = hint & NOTE_PDATAMASK; /* pid */ kev.filter = kn->kn_filter; kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; kev.fflags = kn->kn_sfflags; kev.data = kn->kn_id; /* parent */ kev.udata = kn->kn_kevent.udata; /* preserve udata */ error = kqueue_register(kn->kn_kq, &kev, NULL); if (error) kn->kn_fflags |= NOTE_TRACKERR; } return (kn->kn_fflags != 0); } /* * filt_seltrue: * * This filter "event" routine simulates seltrue(). */ int filt_seltrue(struct knote *kn, long hint) { /* * We don't know how much data can be read/written, * but we know that it *can* be. This is about as * good as select/poll does as well. */ kn->kn_data = 0; return (1); } int sys_kqueue(struct proc *p, void *v, register_t *retval) { struct filedesc *fdp = p->p_fd; struct kqueue *kq; struct file *fp; int fd, error; error = falloc(p, &fp, &fd); if (error) return (error); fp->f_flag = FREAD | FWRITE; fp->f_type = DTYPE_KQUEUE; fp->f_ops = &kqueueops; kq = pool_get(&kqueue_pool, PR_WAITOK); bzero(kq, sizeof(*kq)); TAILQ_INIT(&kq->kq_head); fp->f_data = (caddr_t)kq; *retval = fd; if (fdp->fd_knlistsize < 0) fdp->fd_knlistsize = 0; /* this process has a kq */ kq->kq_fdp = fdp; FILE_SET_MATURE(fp); return (0); } int sys_kevent(struct proc *p, void *v, register_t *retval) { struct filedesc* fdp = p->p_fd; struct sys_kevent_args /* { syscallarg(int) fd; syscallarg(const struct kevent *) changelist; syscallarg(int) nchanges; syscallarg(struct kevent *) eventlist; syscallarg(int) nevents; syscallarg(const struct timespec *) timeout; } */ *uap = v; struct kevent *kevp; struct kqueue *kq; struct file *fp; struct timespec ts; int i, n, nerrors, error; if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL || (fp->f_type != DTYPE_KQUEUE)) return (EBADF); FREF(fp); if (SCARG(uap, timeout) != NULL) { error = copyin(SCARG(uap, timeout), &ts, sizeof(ts)); if (error) goto done; SCARG(uap, timeout) = &ts; } kq = (struct kqueue *)fp->f_data; nerrors = 0; while (SCARG(uap, nchanges) > 0) { n = SCARG(uap, nchanges) > KQ_NEVENTS ? KQ_NEVENTS : SCARG(uap, nchanges); error = copyin(SCARG(uap, changelist), kq->kq_kev, n * sizeof(struct kevent)); if (error) goto done; for (i = 0; i < n; i++) { kevp = &kq->kq_kev[i]; kevp->flags &= ~EV_SYSFLAGS; error = kqueue_register(kq, kevp, p); if (error) { if (SCARG(uap, nevents) != 0) { kevp->flags = EV_ERROR; kevp->data = error; (void) copyout((caddr_t)kevp, (caddr_t)SCARG(uap, eventlist), sizeof(*kevp)); SCARG(uap, eventlist)++; SCARG(uap, nevents)--; nerrors++; } else { goto done; } } } SCARG(uap, nchanges) -= n; SCARG(uap, changelist) += n; } if (nerrors) { *retval = nerrors; error = 0; goto done; } error = kqueue_scan(fp, SCARG(uap, nevents), SCARG(uap, eventlist), SCARG(uap, timeout), p, &n); *retval = n; done: FRELE(fp); return (error); } int kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p) { struct filedesc *fdp = kq->kq_fdp; struct filterops *fops = NULL; struct file *fp = NULL; struct knote *kn = NULL; int s, error = 0; if (kev->filter < 0) { if (kev->filter + EVFILT_SYSCOUNT < 0) return (EINVAL); fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ } if (fops == NULL) { /* * XXX * filter attach routine is responsible for ensuring that * the identifier can be attached to it. */ return (EINVAL); } if (fops->f_isfd) { /* validate descriptor */ if ((fp = fd_getfile(fdp, kev->ident)) == NULL) return (EBADF); FREF(fp); fp->f_count++; if (kev->ident < fdp->fd_knlistsize) { SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) if (kq == kn->kn_kq && kev->filter == kn->kn_filter) break; } } else { if (fdp->fd_knhashmask != 0) { struct klist *list; list = &fdp->fd_knhash[ KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; SLIST_FOREACH(kn, list, kn_link) if (kev->ident == kn->kn_id && kq == kn->kn_kq && kev->filter == kn->kn_filter) break; } } if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { error = ENOENT; goto done; } /* * kn now contains the matching knote, or NULL if no match */ if (kev->flags & EV_ADD) { if (kn == NULL) { kn = knote_alloc(); if (kn == NULL) { error = ENOMEM; goto done; } kn->kn_fp = fp; kn->kn_kq = kq; kn->kn_fop = fops; /* * apply reference count to knote structure, and * do not release it at the end of this routine. */ if (fp != NULL) FRELE(fp); fp = NULL; kn->kn_sfflags = kev->fflags; kn->kn_sdata = kev->data; kev->fflags = 0; kev->data = 0; kn->kn_kevent = *kev; knote_attach(kn, fdp); if ((error = fops->f_attach(kn)) != 0) { knote_drop(kn, p, fdp); goto done; } } else { /* * The user may change some filter values after the * initial EV_ADD, but doing so will not reset any * filters which have already been triggered. */ kn->kn_sfflags = kev->fflags; kn->kn_sdata = kev->data; kn->kn_kevent.udata = kev->udata; } s = splhigh(); if (kn->kn_fop->f_event(kn, 0)) KNOTE_ACTIVATE(kn); splx(s); } else if (kev->flags & EV_DELETE) { kn->kn_fop->f_detach(kn); knote_drop(kn, p, p->p_fd); goto done; } if ((kev->flags & EV_DISABLE) && ((kn->kn_status & KN_DISABLED) == 0)) { s = splhigh(); kn->kn_status |= KN_DISABLED; splx(s); } if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { s = splhigh(); kn->kn_status &= ~KN_DISABLED; if ((kn->kn_status & KN_ACTIVE) && ((kn->kn_status & KN_QUEUED) == 0)) knote_enqueue(kn); splx(s); } done: if (fp != NULL) closef(fp, p); return (error); } int kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, const struct timespec *tsp, struct proc *p, int *retval) { struct kqueue *kq = (struct kqueue *)fp->f_data; struct kevent *kevp; struct timeval atv, rtv, ttv; struct knote *kn, marker; int s, count, timeout, nkev = 0, error = 0; count = maxevents; if (count == 0) goto done; if (tsp != NULL) { TIMESPEC_TO_TIMEVAL(&atv, tsp); if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) { /* No timeout, just poll */ timeout = -1; goto start; } if (itimerfix(&atv)) { error = EINVAL; goto done; } timeout = atv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz(&atv); getmicrouptime(&rtv); timeradd(&atv, &rtv, &atv); } else { atv.tv_sec = 0; atv.tv_usec = 0; timeout = 0; } goto start; retry: if (atv.tv_sec || atv.tv_usec) { getmicrouptime(&rtv); if (timercmp(&rtv, &atv, >=)) goto done; ttv = atv; timersub(&ttv, &rtv, &ttv); timeout = ttv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz(&ttv); } start: kevp = kq->kq_kev; s = splhigh(); if (kq->kq_count == 0) { if (timeout < 0) { error = EWOULDBLOCK; } else { kq->kq_state |= KQ_SLEEP; error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); } splx(s); if (error == 0) goto retry; /* don't restart after signals... */ if (error == ERESTART) error = EINTR; else if (error == EWOULDBLOCK) error = 0; goto done; } TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); while (count) { kn = TAILQ_FIRST(&kq->kq_head); TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); if (kn == &marker) { splx(s); if (count == maxevents) goto retry; goto done; } if (kn->kn_status & KN_DISABLED) { kn->kn_status &= ~KN_QUEUED; kq->kq_count--; continue; } if ((kn->kn_flags & EV_ONESHOT) == 0 && kn->kn_fop->f_event(kn, 0) == 0) { kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); kq->kq_count--; continue; } *kevp = kn->kn_kevent; kevp++; nkev++; if (kn->kn_flags & EV_ONESHOT) { kn->kn_status &= ~KN_QUEUED; kq->kq_count--; splx(s); kn->kn_fop->f_detach(kn); knote_drop(kn, p, p->p_fd); s = splhigh(); } else if (kn->kn_flags & EV_CLEAR) { kn->kn_data = 0; kn->kn_fflags = 0; kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); kq->kq_count--; } else { TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); } count--; if (nkev == KQ_NEVENTS) { splx(s); error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, sizeof(struct kevent) * nkev); ulistp += nkev; nkev = 0; kevp = kq->kq_kev; s = splhigh(); if (error) break; } } TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); splx(s); done: if (nkev != 0) error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, sizeof(struct kevent) * nkev); *retval = maxevents - count; return (error); } /* * XXX * This could be expanded to call kqueue_scan, if desired. */ /*ARGSUSED*/ int kqueue_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) { return (ENXIO); } /*ARGSUSED*/ int kqueue_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) { return (ENXIO); } /*ARGSUSED*/ int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) { return (ENOTTY); } /*ARGSUSED*/ int kqueue_poll(struct file *fp, int events, struct proc *p) { struct kqueue *kq = (struct kqueue *)fp->f_data; int revents = 0; int s = splnet(); if (events & (POLLIN | POLLRDNORM)) { if (kq->kq_count) { revents |= events & (POLLIN | POLLRDNORM); } else { selrecord(p, &kq->kq_sel); kq->kq_state |= KQ_SEL; } } splx(s); return (revents); } /*ARGSUSED*/ int kqueue_stat(struct file *fp, struct stat *st, struct proc *p) { struct kqueue *kq = (struct kqueue *)fp->f_data; bzero((void *)st, sizeof(*st)); st->st_size = kq->kq_count; st->st_blksize = sizeof(struct kevent); st->st_mode = S_IFIFO; return (0); } /*ARGSUSED*/ int kqueue_close(struct file *fp, struct proc *p) { struct kqueue *kq = (struct kqueue *)fp->f_data; struct filedesc *fdp = p->p_fd; struct knote **knp, *kn, *kn0; int i; for (i = 0; i < fdp->fd_knlistsize; i++) { knp = &SLIST_FIRST(&fdp->fd_knlist[i]); kn = *knp; while (kn != NULL) { kn0 = SLIST_NEXT(kn, kn_link); if (kq == kn->kn_kq) { FREF(kn->kn_fp); kn->kn_fop->f_detach(kn); closef(kn->kn_fp, p); knote_free(kn); *knp = kn0; } else { knp = &SLIST_NEXT(kn, kn_link); } kn = kn0; } } if (fdp->fd_knhashmask != 0) { for (i = 0; i < fdp->fd_knhashmask + 1; i++) { knp = &SLIST_FIRST(&fdp->fd_knhash[i]); kn = *knp; while (kn != NULL) { kn0 = SLIST_NEXT(kn, kn_link); if (kq == kn->kn_kq) { kn->kn_fop->f_detach(kn); /* XXX non-fd release of kn->kn_ptr */ knote_free(kn); *knp = kn0; } else { knp = &SLIST_NEXT(kn, kn_link); } kn = kn0; } } } pool_put(&kqueue_pool, kq); fp->f_data = NULL; return (0); } void kqueue_wakeup(struct kqueue *kq) { if (kq->kq_state & KQ_SLEEP) { kq->kq_state &= ~KQ_SLEEP; wakeup(kq); } if (kq->kq_state & KQ_SEL) { kq->kq_state &= ~KQ_SEL; selwakeup(&kq->kq_sel); } KNOTE(&kq->kq_sel.si_note, 0); } /* * walk down a list of knotes, activating them if their event has triggered. */ void knote(struct klist *list, long hint) { struct knote *kn; SLIST_FOREACH(kn, list, kn_selnext) if (kn->kn_fop->f_event(kn, hint)) KNOTE_ACTIVATE(kn); } /* * remove all knotes from a specified klist */ void knote_remove(struct proc *p, struct klist *list) { struct knote *kn; while ((kn = SLIST_FIRST(list)) != NULL) { kn->kn_fop->f_detach(kn); knote_drop(kn, p, p->p_fd); } } /* * remove all knotes referencing a specified fd */ void knote_fdclose(struct proc *p, int fd) { struct filedesc *fdp = p->p_fd; struct klist *list = &fdp->fd_knlist[fd]; knote_remove(p, list); } void knote_attach(struct knote *kn, struct filedesc *fdp) { struct klist *list; int size; if (! kn->kn_fop->f_isfd) { if (fdp->fd_knhashmask == 0) fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP, M_WAITOK, &fdp->fd_knhashmask); list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; goto done; } if (fdp->fd_knlistsize <= kn->kn_id) { size = fdp->fd_knlistsize; while (size <= kn->kn_id) size += KQEXTENT; list = malloc(size * sizeof(struct klist *), M_TEMP, M_WAITOK); bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, fdp->fd_knlistsize * sizeof(struct klist *)); bzero((caddr_t)list + fdp->fd_knlistsize * sizeof(struct klist *), (size - fdp->fd_knlistsize) * sizeof(struct klist *)); if (fdp->fd_knlist != NULL) free(fdp->fd_knlist, M_TEMP); fdp->fd_knlistsize = size; fdp->fd_knlist = list; } list = &fdp->fd_knlist[kn->kn_id]; done: SLIST_INSERT_HEAD(list, kn, kn_link); kn->kn_status = 0; } /* * should be called at spl == 0, since we don't want to hold spl * while calling closef and free. */ void knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp) { struct klist *list; if (kn->kn_fop->f_isfd) list = &fdp->fd_knlist[kn->kn_id]; else list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; SLIST_REMOVE(list, kn, knote, kn_link); if (kn->kn_status & KN_QUEUED) knote_dequeue(kn); if (kn->kn_fop->f_isfd) { FREF(kn->kn_fp); closef(kn->kn_fp, p); } knote_free(kn); } void knote_enqueue(struct knote *kn) { struct kqueue *kq = kn->kn_kq; int s = splhigh(); KASSERT((kn->kn_status & KN_QUEUED) == 0); TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); kn->kn_status |= KN_QUEUED; kq->kq_count++; splx(s); kqueue_wakeup(kq); } void knote_dequeue(struct knote *kn) { struct kqueue *kq = kn->kn_kq; int s = splhigh(); KASSERT(kn->kn_status & KN_QUEUED); TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); kn->kn_status &= ~KN_QUEUED; kq->kq_count--; splx(s); } void klist_invalidate(struct klist *list) { struct knote *kn; SLIST_FOREACH(kn, list, kn_selnext) { kn->kn_status |= KN_DETACHED; kn->kn_flags |= EV_EOF | EV_ONESHOT; } }