+
+/*
+ * 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;
+}
+
+static void
+kqueue_modify (int fd, int oev, int nev)
+{
+ if ((oev ^ new) & 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 ^ new) & 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 (events [i].data == EBADF)
+ fd_kill (events [i].ident);
+ }
+ else
+ event (
+ events [i].ident,
+ events [i].filter == EVFILT_READ ? EV_READ
+ : 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 (struct event_base *base)
+{
+ /* Initalize the kernel queue */
+ if ((kq_fd = kqueue ()) == -1)
+ {
+ free (kqueueop);
+ return;
+ }
+
+ /* Initalize fields */
+ kq_changes = malloc (NEVENT * sizeof (struct kevent));
+ if (!kq_changes)
+ return;
+
+ events = malloc (NEVENT * sizeof (struct kevent));
+ if (!events)
+ {
+ free (kq_changes);
+ return;
+ }
+
+ /* Check for Mac OS X kqueue bug. */
+ kq_changes [0].ident = -1;
+ kq_changes [0].filter = EVFILT_READ;
+ kq_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_fd, kq_changes, 1, kq_events, NEVENT, NULL) != 1
+ || kq_events[0].ident != -1
+ || kq_events[0].flags != EV_ERROR)
+ {
+ /* detected broken kqueue */
+ free (kq_changes);
+ free (kq_events);
+ close (kq_fd);
+ return;
+ }
+
+ ev_method = EVMETHOD_KQUEUE;
+ method_fudge = 1e-3; /* needed to compensate for kevent returning early */
+ method_modify = kq_modify;
+ method_poll = kq_poll;
+
+ kq_eventmax = 64; /* intiial number of events receivable per poll */
+ kq_events = malloc (sizeof (struct kevent) * kq_eventmax);
+}
+
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