Mirror of :pserver:anonymous@cvs.schmorp.de/schmorpforge libev http://software.schmorp.de/pkg/libev.html
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/*
* Copyright 2007 Marc Alexander Lehmann <libev@schmorp.de>
* Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
* 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.
* 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 <sys/types.h>
#include <sys/time.h>
#include <sys/queue.h>
#include <sys/event.h>
#include <string.h>
#include <errno.h>
static int kq_fd;
static struct kevent *kq_changes;
static int kq_changemax, kq_changecnt;
static struct kevent *kq_events;
static int kq_eventmax;
static void
kqueue_change (int fd, int filter, int flags, int fflags)
{
struct kevent *ke;
array_needsize (kq_changes, kq_changemax, ++kq_changecnt, );
ke = &kq_changes [kq_changecnt - 1];
memset (ke, 0, sizeof (struct kevent));
ke->ident = fd;
ke->filter = filter;
ke->flags = flags;
ke->fflags = fflags;
}
#ifndef NOTE_EOF
# define NOTE_EOF 0
#endif
static void
kqueue_modify (int fd, int oev, int nev)
{
if ((oev ^ nev) & EV_READ)
{
if (nev & EV_READ)
kqueue_change (fd, EVFILT_READ, EV_ADD, NOTE_EOF);
else
kqueue_change (fd, EVFILT_READ, EV_DELETE, 0);
}
if ((oev ^ nev) & EV_WRITE)
{
if (nev & EV_WRITE)
kqueue_change (fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
else
kqueue_change (fd, EVFILT_WRITE, EV_DELETE, 0);
}
}
static void
kqueue_poll (ev_tstamp timeout)
{
int res, i;
struct timespec ts;
ts.tv_sec = (time_t)timeout;
ts.tv_nsec = (long)(timeout - (ev_tstamp)ts.tv_sec) * 1e9;
res = kevent (kq_fd, kq_changes, kq_changecnt, kq_events, kq_eventmax, &ts);
kq_changecnt = 0;
if (res < 0)
return;
for (i = 0; i < res; ++i)
{
if (kq_events [i].flags & EV_ERROR)
{
/*
* Error messages that can happen, when a delete fails.
* EBADF happens when the file discriptor has been
* closed,
* ENOENT when the file discriptor was closed and
* then reopened.
* EINVAL for some reasons not understood; EINVAL
* should not be returned ever; but FreeBSD does :-\
* An error is also indicated when a callback deletes
* an event we are still processing. In that case
* the data field is set to ENOENT.
*/
if (kq_events [i].data == EBADF)
fd_kill (kq_events [i].ident);
}
else
fd_event (
kq_events [i].ident,
kq_events [i].filter == EVFILT_READ ? EV_READ
: kq_events [i].filter == EVFILT_WRITE ? EV_WRITE
: 0
);
}
if (expect_false (res == kq_eventmax))
{
free (kq_events);
kq_eventmax = array_roundsize (kq_events, kq_eventmax << 1);
kq_events = malloc (sizeof (struct kevent) * kq_eventmax);
}
}
static void
kqueue_init (int flags)
{
struct kevent ch, ev;
/* Initalize the kernel queue */
if ((kq_fd = kqueue ()) < 0)
return;
/* Check for Mac OS X kqueue bug. */
ch.ident = -1;
ch.filter = EVFILT_READ;
ch.flags = EV_ADD;
/*
* If kqueue works, then kevent will succeed, and it will
* stick an error in ev. If kqueue is broken, then
* kevent will fail.
*/
if (kevent (kq_fd, &ch, 1, &ev, 1, 0) != 1
|| ev.ident != -1
|| ev.flags != EV_ERROR)
{
/* detected broken kqueue */
close (kq_fd);
return;
}
ev_method = EVMETHOD_KQUEUE;
method_fudge = 1e-3; /* needed to compensate for kevent returning early */
method_modify = kqueue_modify;
method_poll = kqueue_poll;
kq_eventmax = 64; /* intiial number of events receivable per poll */
kq_events = malloc (sizeof (struct kevent) * kq_eventmax);
}