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- /* $OpenBSD: kqueue.c,v 1.5 2002/07/10 14:41:31 art Exp $ */
- /*
- * Copyright 2000-2007 Niels Provos <provos@citi.umich.edu>
- * Copyright 2007-2012 Niels Provos and Nick Mathewson
- *
- * 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.
- * 3. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
- */
- #include "event2/event-config.h"
- #include "evconfig-private.h"
- #ifdef EVENT__HAVE_KQUEUE
- #include <sys/types.h>
- #ifdef EVENT__HAVE_SYS_TIME_H
- #include <sys/time.h>
- #endif
- #include <sys/queue.h>
- #include <sys/event.h>
- #include <limits.h>
- #include <signal.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <unistd.h>
- #include <errno.h>
- #ifdef EVENT__HAVE_INTTYPES_H
- #include <inttypes.h>
- #endif
- /* Some platforms apparently define the udata field of struct kevent as
- * intptr_t, whereas others define it as void*. There doesn't seem to be an
- * easy way to tell them apart via autoconf, so we need to use OS macros. */
- #if defined(__NetBSD__)
- #define PTR_TO_UDATA(x) ((typeof(((struct kevent *)0)->udata))(x))
- #define INT_TO_UDATA(x) ((typeof(((struct kevent *)0)->udata))(intptr_t)(x))
- #elif defined(EVENT__HAVE_INTTYPES_H) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__darwin__) && !defined(__APPLE__) && !defined(__CloudABI__)
- #define PTR_TO_UDATA(x) ((intptr_t)(x))
- #define INT_TO_UDATA(x) ((intptr_t)(x))
- #else
- #define PTR_TO_UDATA(x) (x)
- #define INT_TO_UDATA(x) ((void*)(x))
- #endif
- #include "event-internal.h"
- #include "log-internal.h"
- #include "evmap-internal.h"
- #include "event2/thread.h"
- #include "event2/util.h"
- #include "evthread-internal.h"
- #include "changelist-internal.h"
- #include "kqueue-internal.h"
- #define NEVENT 64
- struct kqop {
- struct kevent *changes;
- int changes_size;
- struct kevent *events;
- int events_size;
- int kq;
- int notify_event_added;
- pid_t pid;
- };
- static void kqop_free(struct kqop *kqop);
- static void *kq_init(struct event_base *);
- static int kq_sig_add(struct event_base *, int, short, short, void *);
- static int kq_sig_del(struct event_base *, int, short, short, void *);
- static int kq_dispatch(struct event_base *, struct timeval *);
- static void kq_dealloc(struct event_base *);
- const struct eventop kqops = {
- "kqueue",
- kq_init,
- event_changelist_add_,
- event_changelist_del_,
- kq_dispatch,
- kq_dealloc,
- 1 /* need reinit */,
- EV_FEATURE_ET|EV_FEATURE_O1|EV_FEATURE_FDS,
- EVENT_CHANGELIST_FDINFO_SIZE
- };
- static const struct eventop kqsigops = {
- "kqueue_signal",
- NULL,
- kq_sig_add,
- kq_sig_del,
- NULL,
- NULL,
- 1 /* need reinit */,
- 0,
- 0
- };
- static void *
- kq_init(struct event_base *base)
- {
- int kq = -1;
- struct kqop *kqueueop = NULL;
- if (!(kqueueop = mm_calloc(1, sizeof(struct kqop))))
- return (NULL);
- /* Initialize the kernel queue */
- if ((kq = kqueue()) == -1) {
- event_warn("kqueue");
- goto err;
- }
- kqueueop->kq = kq;
- kqueueop->pid = getpid();
- /* Initialize fields */
- kqueueop->changes = mm_calloc(NEVENT, sizeof(struct kevent));
- if (kqueueop->changes == NULL)
- goto err;
- kqueueop->events = mm_calloc(NEVENT, sizeof(struct kevent));
- if (kqueueop->events == NULL)
- goto err;
- kqueueop->events_size = kqueueop->changes_size = NEVENT;
- /* Check for Mac OS X kqueue bug. */
- memset(&kqueueop->changes[0], 0, sizeof kqueueop->changes[0]);
- kqueueop->changes[0].ident = -1;
- kqueueop->changes[0].filter = EVFILT_READ;
- kqueueop->changes[0].flags = EV_ADD;
- /*
- * If kqueue works, then kevent will succeed, and it will
- * stick an error in events[0]. If kqueue is broken, then
- * kevent will fail.
- */
- if (kevent(kq,
- kqueueop->changes, 1, kqueueop->events, NEVENT, NULL) != 1 ||
- (int)kqueueop->events[0].ident != -1 ||
- !(kqueueop->events[0].flags & EV_ERROR)) {
- event_warn("%s: detected broken kqueue; not using.", __func__);
- goto err;
- }
- base->evsigsel = &kqsigops;
- return (kqueueop);
- err:
- if (kqueueop)
- kqop_free(kqueueop);
- return (NULL);
- }
- #define ADD_UDATA 0x30303
- static void
- kq_setup_kevent(struct kevent *out, evutil_socket_t fd, int filter, short change)
- {
- memset(out, 0, sizeof(struct kevent));
- out->ident = fd;
- out->filter = filter;
- if (change & EV_CHANGE_ADD) {
- out->flags = EV_ADD;
- /* We set a magic number here so that we can tell 'add'
- * errors from 'del' errors. */
- out->udata = INT_TO_UDATA(ADD_UDATA);
- if (change & EV_ET)
- out->flags |= EV_CLEAR;
- #ifdef NOTE_EOF
- /* Make it behave like select() and poll() */
- if (filter == EVFILT_READ)
- out->fflags = NOTE_EOF;
- #endif
- } else {
- EVUTIL_ASSERT(change & EV_CHANGE_DEL);
- out->flags = EV_DELETE;
- }
- }
- static int
- kq_build_changes_list(const struct event_changelist *changelist,
- struct kqop *kqop)
- {
- int i;
- int n_changes = 0;
- for (i = 0; i < changelist->n_changes; ++i) {
- struct event_change *in_ch = &changelist->changes[i];
- struct kevent *out_ch;
- if (n_changes >= kqop->changes_size - 1) {
- int newsize;
- struct kevent *newchanges;
- if (kqop->changes_size > INT_MAX / 2 ||
- (size_t)kqop->changes_size * 2 > EV_SIZE_MAX /
- sizeof(struct kevent)) {
- event_warnx("%s: int overflow", __func__);
- return (-1);
- }
- newsize = kqop->changes_size * 2;
- newchanges = mm_realloc(kqop->changes,
- newsize * sizeof(struct kevent));
- if (newchanges == NULL) {
- event_warn("%s: realloc", __func__);
- return (-1);
- }
- kqop->changes = newchanges;
- kqop->changes_size = newsize;
- }
- if (in_ch->read_change) {
- out_ch = &kqop->changes[n_changes++];
- kq_setup_kevent(out_ch, in_ch->fd, EVFILT_READ,
- in_ch->read_change);
- }
- if (in_ch->write_change) {
- out_ch = &kqop->changes[n_changes++];
- kq_setup_kevent(out_ch, in_ch->fd, EVFILT_WRITE,
- in_ch->write_change);
- }
- }
- return n_changes;
- }
- static int
- kq_grow_events(struct kqop *kqop, size_t new_size)
- {
- struct kevent *newresult;
- newresult = mm_realloc(kqop->events,
- new_size * sizeof(struct kevent));
- if (newresult) {
- kqop->events = newresult;
- kqop->events_size = new_size;
- return 0;
- } else {
- return -1;
- }
- }
- static int
- kq_dispatch(struct event_base *base, struct timeval *tv)
- {
- struct kqop *kqop = base->evbase;
- struct kevent *events = kqop->events;
- struct kevent *changes;
- struct timespec ts, *ts_p = NULL;
- int i, n_changes, res;
- if (tv != NULL) {
- ts.tv_sec = tv->tv_sec;
- ts.tv_nsec = tv->tv_usec * 1000;
- ts_p = &ts;
- }
- /* Build "changes" from "base->changes" */
- EVUTIL_ASSERT(kqop->changes);
- n_changes = kq_build_changes_list(&base->changelist, kqop);
- if (n_changes < 0)
- return -1;
- event_changelist_remove_all_(&base->changelist, base);
- /* steal the changes array in case some broken code tries to call
- * dispatch twice at once. */
- changes = kqop->changes;
- kqop->changes = NULL;
- /* Make sure that 'events' is at least as long as the list of changes:
- * otherwise errors in the changes can get reported as a -1 return
- * value from kevent() rather than as EV_ERROR events in the events
- * array.
- *
- * (We could instead handle -1 return values from kevent() by
- * retrying with a smaller changes array or a larger events array,
- * but this approach seems less risky for now.)
- */
- if (kqop->events_size < n_changes) {
- int new_size = kqop->events_size;
- do {
- new_size *= 2;
- } while (new_size < n_changes);
- kq_grow_events(kqop, new_size);
- events = kqop->events;
- }
- EVBASE_RELEASE_LOCK(base, th_base_lock);
- res = kevent(kqop->kq, changes, n_changes,
- events, kqop->events_size, ts_p);
- EVBASE_ACQUIRE_LOCK(base, th_base_lock);
- EVUTIL_ASSERT(kqop->changes == NULL);
- kqop->changes = changes;
- if (res == -1) {
- if (errno != EINTR) {
- event_warn("kevent");
- return (-1);
- }
- return (0);
- }
- event_debug(("%s: kevent reports %d", __func__, res));
- for (i = 0; i < res; i++) {
- int which = 0;
- if (events[i].flags & EV_ERROR) {
- switch (events[i].data) {
- /* Can occur on delete if we are not currently
- * watching any events on this fd. That can
- * happen when the fd was closed and another
- * file was opened with that fd. */
- case ENOENT:
- /* Can occur for reasons not fully understood
- * on FreeBSD. */
- case EINVAL:
- continue;
- #if defined(__FreeBSD__)
- /*
- * This currently occurs if an FD is closed
- * before the EV_DELETE makes it out via kevent().
- * The FreeBSD capabilities code sees the blank
- * capability set and rejects the request to
- * modify an event.
- *
- * To be strictly correct - when an FD is closed,
- * all the registered events are also removed.
- * Queuing EV_DELETE to a closed FD is wrong.
- * The event(s) should just be deleted from
- * the pending changelist.
- */
- case ENOTCAPABLE:
- continue;
- #endif
- /* Can occur on a delete if the fd is closed. */
- case EBADF:
- /* XXXX On NetBSD, we can also get EBADF if we
- * try to add the write side of a pipe, but
- * the read side has already been closed.
- * Other BSDs call this situation 'EPIPE'. It
- * would be good if we had a way to report
- * this situation. */
- continue;
- /* These two can occur on an add if the fd was one side
- * of a pipe, and the other side was closed. */
- case EPERM:
- case EPIPE:
- /* Report read events, if we're listening for
- * them, so that the user can learn about any
- * add errors. (If the operation was a
- * delete, then udata should be cleared.) */
- if (events[i].udata) {
- /* The operation was an add:
- * report the error as a read. */
- which |= EV_READ;
- break;
- } else {
- /* The operation was a del:
- * report nothing. */
- continue;
- }
- /* Other errors shouldn't occur. */
- default:
- errno = events[i].data;
- return (-1);
- }
- } else if (events[i].filter == EVFILT_READ) {
- which |= EV_READ;
- } else if (events[i].filter == EVFILT_WRITE) {
- which |= EV_WRITE;
- } else if (events[i].filter == EVFILT_SIGNAL) {
- which |= EV_SIGNAL;
- #ifdef EVFILT_USER
- } else if (events[i].filter == EVFILT_USER) {
- base->is_notify_pending = 0;
- #endif
- }
- if (!which)
- continue;
- if (events[i].filter == EVFILT_SIGNAL) {
- evmap_signal_active_(base, events[i].ident, 1);
- } else {
- evmap_io_active_(base, events[i].ident, which | EV_ET);
- }
- }
- if (res == kqop->events_size) {
- /* We used all the events space that we have. Maybe we should
- make it bigger. */
- kq_grow_events(kqop, kqop->events_size * 2);
- }
- return (0);
- }
- static void
- kqop_free(struct kqop *kqop)
- {
- if (kqop->changes)
- mm_free(kqop->changes);
- if (kqop->events)
- mm_free(kqop->events);
- if (kqop->kq >= 0 && kqop->pid == getpid())
- close(kqop->kq);
- memset(kqop, 0, sizeof(struct kqop));
- mm_free(kqop);
- }
- static void
- kq_dealloc(struct event_base *base)
- {
- struct kqop *kqop = base->evbase;
- evsig_dealloc_(base);
- kqop_free(kqop);
- }
- /* signal handling */
- static int
- kq_sig_add(struct event_base *base, int nsignal, short old, short events, void *p)
- {
- struct kqop *kqop = base->evbase;
- struct kevent kev;
- struct timespec timeout = { 0, 0 };
- (void)p;
- EVUTIL_ASSERT(nsignal >= 0 && nsignal < NSIG);
- memset(&kev, 0, sizeof(kev));
- kev.ident = nsignal;
- kev.filter = EVFILT_SIGNAL;
- kev.flags = EV_ADD;
- /* Be ready for the signal if it is sent any
- * time between now and the next call to
- * kq_dispatch. */
- if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1)
- return (-1);
- /* We can set the handler for most signals to SIG_IGN and
- * still have them reported to us in the queue. However,
- * if the handler for SIGCHLD is SIG_IGN, the system reaps
- * zombie processes for us, and we don't get any notification.
- * This appears to be the only signal with this quirk. */
- if (evsig_set_handler_(base, nsignal,
- nsignal == SIGCHLD ? SIG_DFL : SIG_IGN) == -1)
- return (-1);
- return (0);
- }
- static int
- kq_sig_del(struct event_base *base, int nsignal, short old, short events, void *p)
- {
- struct kqop *kqop = base->evbase;
- struct kevent kev;
- struct timespec timeout = { 0, 0 };
- (void)p;
- EVUTIL_ASSERT(nsignal >= 0 && nsignal < NSIG);
- memset(&kev, 0, sizeof(kev));
- kev.ident = nsignal;
- kev.filter = EVFILT_SIGNAL;
- kev.flags = EV_DELETE;
- /* Because we insert signal events
- * immediately, we need to delete them
- * immediately, too */
- if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1)
- return (-1);
- if (evsig_restore_handler_(base, nsignal) == -1)
- return (-1);
- return (0);
- }
- /* OSX 10.6 and FreeBSD 8.1 add support for EVFILT_USER, which we can use
- * to wake up the event loop from another thread. */
- /* Magic number we use for our filter ID. */
- #define NOTIFY_IDENT 42
- int
- event_kq_add_notify_event_(struct event_base *base)
- {
- struct kqop *kqop = base->evbase;
- #if defined(EVFILT_USER) && defined(NOTE_TRIGGER)
- struct kevent kev;
- struct timespec timeout = { 0, 0 };
- #endif
- if (kqop->notify_event_added)
- return 0;
- #if defined(EVFILT_USER) && defined(NOTE_TRIGGER)
- memset(&kev, 0, sizeof(kev));
- kev.ident = NOTIFY_IDENT;
- kev.filter = EVFILT_USER;
- kev.flags = EV_ADD | EV_CLEAR;
- if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1) {
- event_warn("kevent: adding EVFILT_USER event");
- return -1;
- }
- kqop->notify_event_added = 1;
- return 0;
- #else
- return -1;
- #endif
- }
- int
- event_kq_notify_base_(struct event_base *base)
- {
- struct kqop *kqop = base->evbase;
- #if defined(EVFILT_USER) && defined(NOTE_TRIGGER)
- struct kevent kev;
- struct timespec timeout = { 0, 0 };
- #endif
- if (! kqop->notify_event_added)
- return -1;
- #if defined(EVFILT_USER) && defined(NOTE_TRIGGER)
- memset(&kev, 0, sizeof(kev));
- kev.ident = NOTIFY_IDENT;
- kev.filter = EVFILT_USER;
- kev.fflags = NOTE_TRIGGER;
- if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1) {
- event_warn("kevent: triggering EVFILT_USER event");
- return -1;
- }
- return 0;
- #else
- return -1;
- #endif
- }
- #endif /* EVENT__HAVE_KQUEUE */
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