/*- * 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 1.2.2.10 2004/04/04 07:03:14 cperciva Exp $ * $DragonFly: src/sys/kern/kern_event.c,v 1.33 2007/02/03 17:05:57 corecode Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); static int kqueue_scan(struct kqueue *kq, struct kevent *kevp, int count, struct timespec *tsp, int *errorp); static int kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags); static int kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags); static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct ucred *cred, struct sysmsg *msg); static int kqueue_poll(struct file *fp, int events, struct ucred *cred); static int kqueue_kqfilter(struct file *fp, struct knote *kn); static int kqueue_stat(struct file *fp, struct stat *st, struct ucred *cred); static int kqueue_close(struct file *fp); static void kqueue_wakeup(struct kqueue *kq); /* * MPSAFE */ static struct fileops kqueueops = { .fo_read = kqueue_read, .fo_write = kqueue_write, .fo_ioctl = kqueue_ioctl, .fo_poll = kqueue_poll, .fo_kqfilter = kqueue_kqfilter, .fo_stat = kqueue_stat, .fo_close = kqueue_close, .fo_shutdown = nofo_shutdown }; static void knote_attach(struct knote *kn); static void knote_drop(struct knote *kn); static void knote_enqueue(struct knote *kn); static void knote_dequeue(struct knote *kn); static void knote_init(void); static struct knote *knote_alloc(void); static void knote_free(struct knote *kn); static void filt_kqdetach(struct knote *kn); static int filt_kqueue(struct knote *kn, long hint); static int filt_procattach(struct knote *kn); static void filt_procdetach(struct knote *kn); static int filt_proc(struct knote *kn, long hint); static int filt_fileattach(struct knote *kn); static void filt_timerexpire(void *knx); static int filt_timerattach(struct knote *kn); static void filt_timerdetach(struct knote *kn); static int filt_timer(struct knote *kn, long hint); static struct filterops file_filtops = { 1, filt_fileattach, NULL, NULL }; static struct filterops kqread_filtops = { 1, NULL, filt_kqdetach, filt_kqueue }; static struct filterops proc_filtops = { 0, filt_procattach, filt_procdetach, filt_proc }; static struct filterops timer_filtops = { 0, filt_timerattach, filt_timerdetach, filt_timer }; static vm_zone_t knote_zone; static int kq_ncallouts = 0; static int kq_calloutmax = (4 * 1024); SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); #define KNOTE_ACTIVATE(kn) do { \ kn->kn_status |= KN_ACTIVE; \ if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ knote_enqueue(kn); \ } while(0) #define KN_HASHSIZE 64 /* XXX should be tunable */ #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) extern struct filterops aio_filtops; extern struct filterops sig_filtops; /* * Table for for all system-defined filters. */ static struct filterops *sysfilt_ops[] = { &file_filtops, /* EVFILT_READ */ &file_filtops, /* EVFILT_WRITE */ &aio_filtops, /* EVFILT_AIO */ &file_filtops, /* EVFILT_VNODE */ &proc_filtops, /* EVFILT_PROC */ &sig_filtops, /* EVFILT_SIGNAL */ &timer_filtops, /* EVFILT_TIMER */ }; static int filt_fileattach(struct knote *kn) { return (fo_kqfilter(kn->kn_fp, kn)); } /* * MPALMOSTSAFE - acquires mplock */ static int kqueue_kqfilter(struct file *fp, struct knote *kn) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; get_mplock(); if (kn->kn_filter != EVFILT_READ) { rel_mplock(); return (1); } kn->kn_fop = &kqread_filtops; SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); rel_mplock(); return (0); } static void filt_kqdetach(struct knote *kn) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); } /*ARGSUSED*/ static int filt_kqueue(struct knote *kn, long hint) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; kn->kn_data = kq->kq_count; return (kn->kn_data > 0); } static int filt_procattach(struct knote *kn) { struct proc *p; int immediate; immediate = 0; p = pfind(kn->kn_id); if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { p = zpfind(kn->kn_id); immediate = 1; } if (p == NULL) return (ESRCH); if (!PRISON_CHECK(curthread->td_ucred, p->p_ucred)) 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); /* * Immediately activate any exit notes if the target process is a * zombie. This is necessary to handle the case where the target * process, e.g. a child, dies before the kevent is registered. */ if (immediate && filt_proc(kn, NOTE_EXIT)) KNOTE_ACTIVATE(kn); return (0); } /* * The knote may be attached to a different process, which may exit, * leaving nothing for the knote to be attached to. So when the process * exits, the knote is marked as DETACHED and also flagged as ONESHOT so * it will be deleted when read out. However, as part of the knote deletion, * this routine is called, so a check is needed to avoid actually performing * a detach, because the original process does not exist any more. */ static void filt_procdetach(struct knote *kn) { struct proc *p; if (kn->kn_status & KN_DETACHED) return; /* XXX locking? this might modify another process. */ p = kn->kn_ptr.p_proc; SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); } static int filt_proc(struct knote *kn, long hint) { u_int event; /* * mask off extra data */ event = (u_int)hint & NOTE_PCTRLMASK; /* * if the user is interested in this event, record it. */ if (kn->kn_sfflags & event) kn->kn_fflags |= event; /* * Process is gone, so flag the event as finished. Detach the * knote from the process now because the process will be poof, * gone later on. */ if (event == NOTE_EXIT) { struct proc *p = kn->kn_ptr.p_proc; if ((kn->kn_status & KN_DETACHED) == 0) { SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); kn->kn_status |= KN_DETACHED; kn->kn_data = p->p_xstat; kn->kn_ptr.p_proc = NULL; } 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); if (error) kn->kn_fflags |= NOTE_TRACKERR; } return (kn->kn_fflags != 0); } static void filt_timerexpire(void *knx) { struct knote *kn = knx; struct callout *calloutp; struct timeval tv; int tticks; kn->kn_data++; KNOTE_ACTIVATE(kn); if ((kn->kn_flags & EV_ONESHOT) == 0) { tv.tv_sec = kn->kn_sdata / 1000; tv.tv_usec = (kn->kn_sdata % 1000) * 1000; tticks = tvtohz_high(&tv); calloutp = (struct callout *)kn->kn_hook; callout_reset(calloutp, tticks, filt_timerexpire, kn); } } /* * data contains amount of time to sleep, in milliseconds */ static int filt_timerattach(struct knote *kn) { struct callout *calloutp; struct timeval tv; int tticks; if (kq_ncallouts >= kq_calloutmax) return (ENOMEM); kq_ncallouts++; tv.tv_sec = kn->kn_sdata / 1000; tv.tv_usec = (kn->kn_sdata % 1000) * 1000; tticks = tvtohz_high(&tv); kn->kn_flags |= EV_CLEAR; /* automatically set */ MALLOC(calloutp, struct callout *, sizeof(*calloutp), M_KQUEUE, M_WAITOK); callout_init(calloutp); kn->kn_hook = (caddr_t)calloutp; callout_reset(calloutp, tticks, filt_timerexpire, kn); return (0); } static void filt_timerdetach(struct knote *kn) { struct callout *calloutp; calloutp = (struct callout *)kn->kn_hook; callout_stop(calloutp); FREE(calloutp, M_KQUEUE); kq_ncallouts--; } static int filt_timer(struct knote *kn, long hint) { return (kn->kn_data != 0); } /* * Initialize a kqueue. * * NOTE: The lwp/proc code initializes a kqueue for select/poll ops. * * MPSAFE */ void kqueue_init(struct kqueue *kq, struct filedesc *fdp) { TAILQ_INIT(&kq->kq_knpend); TAILQ_INIT(&kq->kq_knlist); kq->kq_fdp = fdp; } /* * Terminate a kqueue. Freeing the actual kq itself is left up to the * caller (it might be embedded in a lwp so we don't do it here). */ void kqueue_terminate(struct kqueue *kq) { struct knote *kn; struct klist *list; int hv; while ((kn = TAILQ_FIRST(&kq->kq_knlist)) != NULL) { kn->kn_fop->f_detach(kn); if (kn->kn_fop->f_isfd) { list = &kn->kn_fp->f_klist; SLIST_REMOVE(list, kn, knote, kn_link); fdrop(kn->kn_fp); kn->kn_fp = NULL; } else { hv = KN_HASH(kn->kn_id, kq->kq_knhashmask); list = &kq->kq_knhash[hv]; SLIST_REMOVE(list, kn, knote, kn_link); } TAILQ_REMOVE(&kq->kq_knlist, kn, kn_kqlink); if (kn->kn_status & KN_QUEUED) knote_dequeue(kn); knote_free(kn); } if (kq->kq_knhash) { kfree(kq->kq_knhash, M_KQUEUE); kq->kq_knhash = NULL; kq->kq_knhashmask = 0; } } /* * MPSAFE */ int sys_kqueue(struct kqueue_args *uap) { struct thread *td = curthread; struct kqueue *kq; struct file *fp; int fd, error; error = falloc(td->td_lwp, &fp, &fd); if (error) return (error); fp->f_flag = FREAD | FWRITE; fp->f_type = DTYPE_KQUEUE; fp->f_ops = &kqueueops; kq = kmalloc(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO); kqueue_init(kq, td->td_proc->p_fd); fp->f_data = kq; fsetfd(kq->kq_fdp, fp, fd); uap->sysmsg_result = fd; fdrop(fp); return (error); } /* * Copy 'count' items into the destination list pointed to by uap->eventlist. */ static int kevent_copyout(void *arg, struct kevent *kevp, int count) { struct kevent_args *uap; int error; uap = (struct kevent_args *)arg; error = copyout(kevp, uap->eventlist, count * sizeof *kevp); if (error == 0) uap->eventlist += count; return (error); } /* * Copy 'count' items from the list pointed to by uap->changelist. */ static int kevent_copyin(void *arg, struct kevent *kevp, int count) { struct kevent_args *uap; int error; uap = (struct kevent_args *)arg; error = copyin(uap->changelist, kevp, count * sizeof *kevp); if (error == 0) uap->changelist += count; return (error); } /* * MPALMOSTSAFE */ int kern_kevent(int fd, int nchanges, int nevents, struct kevent_args *uap, k_copyin_fn kevent_copyinfn, k_copyout_fn kevent_copyoutfn, struct timespec *tsp_in) { struct thread *td = curthread; struct proc *p = td->td_proc; struct kevent *kevp; struct kqueue *kq; struct file *fp = NULL; struct timespec ts; struct timespec *tsp; int i, n, total, nerrors, error; struct kevent kev[KQ_NEVENTS]; tsp = tsp_in; fp = holdfp(p->p_fd, fd, -1); if (fp == NULL) return (EBADF); if (fp->f_type != DTYPE_KQUEUE) { fdrop(fp); return (EBADF); } kq = (struct kqueue *)fp->f_data; nerrors = 0; get_mplock(); while (nchanges > 0) { n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; error = kevent_copyinfn(uap, kev, n); if (error) goto done; for (i = 0; i < n; i++) { kevp = &kev[i]; kevp->flags &= ~EV_SYSFLAGS; error = kqueue_register(kq, kevp); if (error) { if (nevents != 0) { kevp->flags = EV_ERROR; kevp->data = error; kevent_copyoutfn(uap, kevp, 1); nevents--; nerrors++; } else { goto done; } } } nchanges -= n; } if (nerrors) { uap->sysmsg_result = nerrors; error = 0; goto done; } /* * Acquire/wait for events - setup timeout */ if (tsp != NULL) { struct timespec ats; if (tsp->tv_sec || tsp->tv_nsec) { nanouptime(&ats); timespecadd(tsp, &ats); /* tsp = target time */ } } /* * Loop as required. * * Collect as many events as we can. The timeout on successive * loops is disabled (kqueue_scan() becomes non-blocking). */ total = 0; error = 0; while ((n = nevents - total) > 0) { if (n > KQ_NEVENTS) n = KQ_NEVENTS; i = kqueue_scan(kq, kev, n, tsp, &error); if (i == 0) break; error = kevent_copyoutfn(uap, kev, i); total += i; if (error || i != n) break; tsp = &ts; /* successive loops non-blocking */ tsp->tv_sec = 0; tsp->tv_nsec = 0; } uap->sysmsg_result = total; done: rel_mplock(); if (fp != NULL) fdrop(fp); return (error); } /* * MPALMOSTSAFE */ int sys_kevent(struct kevent_args *uap) { struct timespec ts, *tsp; int error; if (uap->timeout) { error = copyin(uap->timeout, &ts, sizeof(ts)); if (error) return (error); tsp = &ts; } else { tsp = NULL; } error = kern_kevent(uap->fd, uap->nchanges, uap->nevents, uap, kevent_copyin, kevent_copyout, tsp); return (error); } int kqueue_register(struct kqueue *kq, struct kevent *kev) { struct filedesc *fdp = kq->kq_fdp; struct filterops *fops; struct file *fp = NULL; struct knote *kn = NULL; int error = 0; if (kev->filter < 0) { if (kev->filter + EVFILT_SYSCOUNT < 0) return (EINVAL); fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ } else { /* * XXX * filter attach routine is responsible for insuring that * the identifier can be attached to it. */ kprintf("unknown filter: %d\n", kev->filter); return (EINVAL); } if (fops->f_isfd) { /* validate descriptor */ fp = holdfp(fdp, kev->ident, -1); if (fp == NULL) return (EBADF); SLIST_FOREACH(kn, &fp->f_klist, kn_link) { if (kn->kn_kq == kq && kn->kn_filter == kev->filter && kn->kn_id == kev->ident) { break; } } } else { if (kq->kq_knhashmask) { struct klist *list; list = &kq->kq_knhash[ KN_HASH((u_long)kev->ident, kq->kq_knhashmask)]; SLIST_FOREACH(kn, list, kn_link) { if (kn->kn_id == kev->ident && kn->kn_filter == kev->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. */ 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); if ((error = fops->f_attach(kn)) != 0) { knote_drop(kn); goto done; } } else { /* * The user may change some filter values after the * initial EV_ADD, but doing so will not reset any * filter which have already been triggered. */ kn->kn_sfflags = kev->fflags; kn->kn_sdata = kev->data; kn->kn_kevent.udata = kev->udata; } crit_enter(); if (kn->kn_fop->f_event(kn, 0)) KNOTE_ACTIVATE(kn); crit_exit(); } else if (kev->flags & EV_DELETE) { kn->kn_fop->f_detach(kn); knote_drop(kn); goto done; } if ((kev->flags & EV_DISABLE) && ((kn->kn_status & KN_DISABLED) == 0)) { crit_enter(); kn->kn_status |= KN_DISABLED; crit_exit(); } if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { crit_enter(); kn->kn_status &= ~KN_DISABLED; if ((kn->kn_status & KN_ACTIVE) && ((kn->kn_status & KN_QUEUED) == 0)) knote_enqueue(kn); crit_exit(); } done: if (fp != NULL) fdrop(fp); return (error); } /* * Scan the kqueue, blocking if necessary until the target time is reached. * If tsp is NULL we block indefinitely. If tsp->ts_secs/nsecs are both * 0 we do not block at all. */ static int kqueue_scan(struct kqueue *kq, struct kevent *kevp, int count, struct timespec *tsp, int *errorp) { struct knote *kn, marker; int total; total = 0; again: crit_enter(); if (kq->kq_count == 0) { if (tsp == NULL) { kq->kq_state |= KQ_SLEEP; *errorp = tsleep(kq, PCATCH, "kqread", 0); } else if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) { *errorp = EWOULDBLOCK; } else { struct timespec ats; struct timespec atx = *tsp; int timeout; nanouptime(&ats); timespecsub(&atx, &ats); if (ats.tv_sec < 0) { *errorp = EWOULDBLOCK; } else { timeout = atx.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tstohz_high(&atx); kq->kq_state |= KQ_SLEEP; *errorp = tsleep(kq, PCATCH, "kqread", timeout); } } crit_exit(); if (*errorp == 0) goto again; /* don't restart after signals... */ if (*errorp == ERESTART) *errorp = EINTR; else if (*errorp == EWOULDBLOCK) *errorp = 0; goto done; } /* * Collect events. Continuous mode events may get recycled * past the marker so we stop when we hit it unless no events * have been collected. */ TAILQ_INSERT_TAIL(&kq->kq_knpend, &marker, kn_tqe); while (count) { kn = TAILQ_FIRST(&kq->kq_knpend); if (kn == &marker) break; TAILQ_REMOVE(&kq->kq_knpend, kn, kn_tqe); 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; ++total; --count; /* * Post-event action on the note */ if (kn->kn_flags & EV_ONESHOT) { kn->kn_status &= ~KN_QUEUED; kq->kq_count--; crit_exit(); kn->kn_fop->f_detach(kn); knote_drop(kn); crit_enter(); } 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_knpend, kn, kn_tqe); } } TAILQ_REMOVE(&kq->kq_knpend, &marker, kn_tqe); crit_exit(); if (total == 0) goto again; done: return (total); } /* * XXX * This could be expanded to call kqueue_scan, if desired. * * MPSAFE */ static int kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags) { return (ENXIO); } /* * MPSAFE */ static int kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags) { return (ENXIO); } /* * MPALMOSTSAFE */ static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct ucred *cred, struct sysmsg *msg) { struct kqueue *kq; int error; get_mplock(); kq = (struct kqueue *)fp->f_data; switch(com) { case FIOASYNC: if (*(int *)data) kq->kq_state |= KQ_ASYNC; else kq->kq_state &= ~KQ_ASYNC; error = 0; break; case FIOSETOWN: error = fsetown(*(int *)data, &kq->kq_sigio); break; default: error = ENOTTY; break; } rel_mplock(); return (error); } /* * MPALMOSTSAFE - acquires mplock */ static int kqueue_poll(struct file *fp, int events, struct ucred *cred) { struct kqueue *kq = (struct kqueue *)fp->f_data; int revents = 0; get_mplock(); crit_enter(); if (events & (POLLIN | POLLRDNORM)) { if (kq->kq_count) { revents |= events & (POLLIN | POLLRDNORM); } else { selrecord(curthread, &kq->kq_sel); kq->kq_state |= KQ_SEL; } } crit_exit(); rel_mplock(); return (revents); } /* * MPSAFE */ static int kqueue_stat(struct file *fp, struct stat *st, struct ucred *cred) { 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); } /* * MPALMOSTSAFE - acquires mplock */ static int kqueue_close(struct file *fp) { struct kqueue *kq = (struct kqueue *)fp->f_data; get_mplock(); kqueue_terminate(kq); fp->f_data = NULL; funsetown(kq->kq_sigio); rel_mplock(); kfree(kq, M_KQUEUE); return (0); } static void kqueue_wakeup(struct kqueue *kq) { if (kq->kq_state & KQ_SLEEP) { kq->kq_state &= ~KQ_SLEEP; wakeup(kq); } if (kq->kq_state & KQ_SEL) { kq->kq_state &= ~KQ_SEL; selwakeup(&kq->kq_sel); } KNOTE(&kq->kq_sel.si_note, 0); } /* * walk down a list of knotes, activating them if their event has triggered. */ void knote(struct klist *list, long hint) { struct knote *kn; SLIST_FOREACH(kn, list, kn_selnext) if (kn->kn_fop->f_event(kn, hint)) KNOTE_ACTIVATE(kn); } /* * remove all knotes from a specified klist */ void knote_remove(struct klist *list) { struct knote *kn; while ((kn = SLIST_FIRST(list)) != NULL) { kn->kn_fop->f_detach(kn); knote_drop(kn); } } /* * remove all knotes referencing a specified fd */ void knote_fdclose(struct file *fp, struct filedesc *fdp, int fd) { struct knote *kn; restart: SLIST_FOREACH(kn, &fp->f_klist, kn_link) { if (kn->kn_kq->kq_fdp == fdp && kn->kn_id == fd) { kn->kn_fop->f_detach(kn); knote_drop(kn); goto restart; } } } static void knote_attach(struct knote *kn) { struct klist *list; struct kqueue *kq = kn->kn_kq; if (kn->kn_fop->f_isfd) { KKASSERT(kn->kn_fp); list = &kn->kn_fp->f_klist; } else { if (kq->kq_knhashmask == 0) kq->kq_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, &kq->kq_knhashmask); list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; } SLIST_INSERT_HEAD(list, kn, kn_link); TAILQ_INSERT_HEAD(&kq->kq_knlist, kn, kn_kqlink); kn->kn_status = 0; } /* * should be called outside of a critical section, since we don't want to * hold a critical section while calling fdrop and free. */ static void knote_drop(struct knote *kn) { struct kqueue *kq; struct klist *list; kq = kn->kn_kq; if (kn->kn_fop->f_isfd) list = &kn->kn_fp->f_klist; else list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)]; SLIST_REMOVE(list, kn, knote, kn_link); TAILQ_REMOVE(&kq->kq_knlist, kn, kn_kqlink); if (kn->kn_status & KN_QUEUED) knote_dequeue(kn); if (kn->kn_fop->f_isfd) fdrop(kn->kn_fp); knote_free(kn); } static void knote_enqueue(struct knote *kn) { struct kqueue *kq = kn->kn_kq; crit_enter(); KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); TAILQ_INSERT_TAIL(&kq->kq_knpend, kn, kn_tqe); kn->kn_status |= KN_QUEUED; ++kq->kq_count; /* * Send SIGIO on request (typically set up as a mailbox signal) */ if (kq->kq_sigio && (kq->kq_state & KQ_ASYNC) && kq->kq_count == 1) pgsigio(kq->kq_sigio, SIGIO, 0); crit_exit(); kqueue_wakeup(kq); } static void knote_dequeue(struct knote *kn) { struct kqueue *kq = kn->kn_kq; KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); crit_enter(); TAILQ_REMOVE(&kq->kq_knpend, kn, kn_tqe); kn->kn_status &= ~KN_QUEUED; kq->kq_count--; crit_exit(); } static void knote_init(void) { knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1); } SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL) static struct knote * knote_alloc(void) { return ((struct knote *)zalloc(knote_zone)); } static void knote_free(struct knote *kn) { zfree(knote_zone, kn); }