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/*
* libev kqueue backend
*
* Copyright (c) 2007,2008,2009,2010,2011,2012,2013 Marc Alexander Lehmann <libev@schmorp.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modifica-
* tion, 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 ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
* CIAL, 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 OTH-
* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License ("GPL") version 2 or any later version,
* in which case the provisions of the GPL are applicable instead of
* the above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use your
* version of this file under the BSD license, indicate your decision
* by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL. If you do not delete the
* provisions above, a recipient may use your version of this file under
* either the BSD or the GPL.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/event.h>
#include <string.h>
#include <errno.h>
void inline_speed
kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
{
++kqueue_changecnt;
array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
}
/* OS X at least needs this */
#ifndef EV_ENABLE
# define EV_ENABLE 0
#endif
#ifndef NOTE_EOF
# define NOTE_EOF 0
#endif
static void
kqueue_modify (EV_P_ int fd, int oev, int nev)
{
if (oev != nev)
{
if (oev & EV_READ)
kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
if (oev & EV_WRITE)
kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
}
/* to detect close/reopen reliably, we have to re-add */
/* event requests even when oev == nev */
if (nev & EV_READ)
kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD | EV_ENABLE, NOTE_EOF);
if (nev & EV_WRITE)
kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, NOTE_EOF);
}
static void
kqueue_poll (EV_P_ ev_tstamp timeout)
{
int res, i;
struct timespec ts;
/* need to resize so there is enough space for errors */
if (kqueue_changecnt > kqueue_eventmax)
{
ev_free (kqueue_events);
kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_changecnt);
kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
}
EV_RELEASE_CB;
EV_TS_SET (ts, timeout);
res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
EV_ACQUIRE_CB;
kqueue_changecnt = 0;
if (expect_false (res < 0))
{
if (errno != EINTR)
ev_syserr ("(libev) kevent");
return;
}
for (i = 0; i < res; ++i)
{
int fd = kqueue_events [i].ident;
if (expect_false (kqueue_events [i].flags & EV_ERROR))
{
int err = kqueue_events [i].data;
/* we are only interested in errors for fds that we are interested in :) */
if (anfds [fd].events)
{
if (err == ENOENT) /* resubmit changes on ENOENT */
kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
else if (err == EBADF) /* on EBADF, we re-check the fd */
{
if (fd_valid (fd))
kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
else
fd_kill (EV_A_ fd);
}
else /* on all other errors, we error out on the fd */
fd_kill (EV_A_ fd);
}
}
else
fd_event (
EV_A_
fd,
kqueue_events [i].filter == EVFILT_READ ? EV_READ
: kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
: 0
);
}
if (expect_false (res == kqueue_eventmax))
{
ev_free (kqueue_events);
kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
}
}
int inline_size
kqueue_init (EV_P_ int flags)
{
/* initialize the kernel queue */
kqueue_fd_pid = getpid ();
if ((backend_fd = kqueue ()) < 0)
return 0;
fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
backend_modify = kqueue_modify;
backend_poll = kqueue_poll;
kqueue_eventmax = 64; /* initial number of events receivable per poll */
kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
kqueue_changes = 0;
kqueue_changemax = 0;
kqueue_changecnt = 0;
return EVBACKEND_KQUEUE;
}
void inline_size
kqueue_destroy (EV_P)
{
ev_free (kqueue_events);
ev_free (kqueue_changes);
}
void inline_size
kqueue_fork (EV_P)
{
/* some BSD kernels don't just destroy the kqueue itself,
* but also close the fd, which isn't documented, and
* impossible to support properly.
* we remember the pid of the kqueue call and only close
* the fd if the pid is still the same.
* this leaks fds on sane kernels, but BSD interfaces are
* notoriously buggy and rarely get fixed.
*/
pid_t newpid = getpid ();
if (newpid == kqueue_fd_pid)
close (backend_fd);
kqueue_fd_pid = newpid;
while ((backend_fd = kqueue ()) < 0)
ev_syserr ("(libev) kqueue");
fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
/* re-register interest in fds */
fd_rearm_all (EV_A);
}
/* sys/event.h defines EV_ERROR */
#undef EV_ERROR