libev/ev_kqueue.c

/*
 * 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 void
kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
{
  struct kevent *ke;

  ++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);
}

#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, NOTE_EOF);

  if (nev & EV_WRITE)
    kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD, 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_roundsize (struct kevent, kqueue_changecnt);
      kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
    }

  ts.tv_sec  = (time_t)timeout;
  ts.tv_nsec = (long)((timeout - (ev_tstamp)ts.tv_sec) * 1e9);
  res = kevent (kqueue_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
  kqueue_changecnt = 0;

  if (res < 0)
    { 
      if (errno != EINTR)
        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;

          /* 
           * errors that may happen
           *   EBADF happens when the file discriptor has been
           *   closed,
           *   ENOENT when the file descriptor was closed and
           *   then reopened.
           *   EINVAL for some reasons not understood; EINVAL
           *   should not be returned ever; but FreeBSD does :-\
           */

          /* 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_roundsize (struct kevent, kqueue_eventmax << 1);
      kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
    }
}

static int
kqueue_init (EV_P_ int flags)
{
  struct kevent ch, ev;

  /* Initalize the kernel queue */
  if ((kqueue_fd = kqueue ()) < 0)
    return 0;

  fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */

  /* 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 (kqueue_fd, &ch, 1, &ev, 1, 0) != 1
      || ev.ident != -1
      || ev.flags != EV_ERROR)
    {
      /* detected broken kqueue */
      close (kqueue_fd);
      return 0;
    }

  backend_fudge  = 1e-3; /* needed to compensate for kevent returning early */
  backend_modify = kqueue_modify;
  backend_poll   = kqueue_poll;

  kqueue_eventmax = 64; /* intiial 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;
}

static void
kqueue_destroy (EV_P)
{
  close (kqueue_fd);

  ev_free (kqueue_events);
  ev_free (kqueue_changes);
}

static void
kqueue_fork (EV_P)
{
  close (kqueue_fd);

  while ((kqueue_fd = kqueue ()) < 0)
    syserr ("(libev) kqueue");

  fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC);

  /* re-register interest in fds */
  fd_rearm_all (EV_A);
}

Revision:	1.24
Committed:	Fri Nov 23 13:08:57 2007 UTC (16 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.23:	+1 -1 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* Copyright 2007 Marc Alexander Lehmann <libev@schmorp.de>
3	* Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
4	* All rights reserved.
5	*
6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions
8	* are met:
9	*
10	* 1. Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.
12	* 2. Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.
15	* 3. The name of the author may not be used to endorse or promote products
16	* derived from this software without specific prior written permission.
17	*
18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28	*/
29
30	#include <sys/types.h>
31	#include <sys/time.h>
32	#include <sys/queue.h>
33	#include <sys/event.h>
34	#include <string.h>
35	#include <errno.h>
36
37	static void
38	kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
39	{
40	struct kevent *ke;
41
42	++kqueue_changecnt;
43	array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
44
45	EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
46	}
47
48	#ifndef NOTE_EOF
49	# define NOTE_EOF 0
50	#endif
51
52	static void
53	kqueue_modify (EV_P_ int fd, int oev, int nev)
54	{
55	if (oev != nev)
56	{
57	if (oev & EV_READ)
58	kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
59
60	if (oev & EV_WRITE)
61	kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
62	}
63
64	/* to detect close/reopen reliably, we have to re-add */
65	/* event requests even when oev == nev */
66
67	if (nev & EV_READ)
68	kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD, NOTE_EOF);
69
70	if (nev & EV_WRITE)
71	kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
72	}
73
74	static void
75	kqueue_poll (EV_P_ ev_tstamp timeout)
76	{
77	int res, i;
78	struct timespec ts;
79
80	/* need to resize so there is enough space for errors */
81	if (kqueue_changecnt > kqueue_eventmax)
82	{
83	ev_free (kqueue_events);
84	kqueue_eventmax = array_roundsize (struct kevent, kqueue_changecnt);
85	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
86	}
87
88	ts.tv_sec = (time_t)timeout;
89	ts.tv_nsec = (long)((timeout - (ev_tstamp)ts.tv_sec) * 1e9);
90	res = kevent (kqueue_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
91	kqueue_changecnt = 0;
92
93	if (res < 0)
94	{
95	if (errno != EINTR)
96	syserr ("(libev) kevent");
97
98	return;
99	}
100
101	for (i = 0; i < res; ++i)
102	{
103	int fd = kqueue_events [i].ident;
104
105	if (expect_false (kqueue_events [i].flags & EV_ERROR))
106	{
107	int err = kqueue_events [i].data;
108
109	/*
110	* errors that may happen
111	* EBADF happens when the file discriptor has been
112	* closed,
113	* ENOENT when the file descriptor was closed and
114	* then reopened.
115	* EINVAL for some reasons not understood; EINVAL
116	* should not be returned ever; but FreeBSD does :-\
117	*/
118
119	/* we are only interested in errors for fds that we are interested in :) */
120	if (anfds [fd].events)
121	{
122	if (err == ENOENT) /* resubmit changes on ENOENT */
123	kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
124	else if (err == EBADF) /* on EBADF, we re-check the fd */
125	{
126	if (fd_valid (fd))
127	kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
128	else
129	fd_kill (EV_A_ fd);
130	}
131	else /* on all other errors, we error out on the fd */
132	fd_kill (EV_A_ fd);
133	}
134	}
135	else
136	fd_event (
137	EV_A_
138	fd,
139	kqueue_events [i].filter == EVFILT_READ ? EV_READ
140	: kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
141	: 0
142	);
143	}
144
145	if (expect_false (res == kqueue_eventmax))
146	{
147	ev_free (kqueue_events);
148	kqueue_eventmax = array_roundsize (struct kevent, kqueue_eventmax << 1);
149	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
150	}
151	}
152
153	static int
154	kqueue_init (EV_P_ int flags)
155	{
156	struct kevent ch, ev;
157
158	/* Initalize the kernel queue */
159	if ((kqueue_fd = kqueue ()) < 0)
160	return 0;
161
162	fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
163
164	/* Check for Mac OS X kqueue bug. */
165	ch.ident = -1;
166	ch.filter = EVFILT_READ;
167	ch.flags = EV_ADD;
168
169	/*
170	* If kqueue works, then kevent will succeed, and it will
171	* stick an error in ev. If kqueue is broken, then
172	* kevent will fail.
173	*/
174	if (kevent (kqueue_fd, &ch, 1, &ev, 1, 0) != 1
175	\|\| ev.ident != -1
176	\|\| ev.flags != EV_ERROR)
177	{
178	/* detected broken kqueue */
179	close (kqueue_fd);
180	return 0;
181	}
182
183	backend_fudge = 1e-3; /* needed to compensate for kevent returning early */
184	backend_modify = kqueue_modify;
185	backend_poll = kqueue_poll;
186
187	kqueue_eventmax = 64; /* intiial number of events receivable per poll */
188	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
189
190	kqueue_changes = 0;
191	kqueue_changemax = 0;
192	kqueue_changecnt = 0;
193
194	return EVBACKEND_KQUEUE;
195	}
196
197	static void
198	kqueue_destroy (EV_P)
199	{
200	close (kqueue_fd);
201
202	ev_free (kqueue_events);
203	ev_free (kqueue_changes);
204	}
205
206	static void
207	kqueue_fork (EV_P)
208	{
209	close (kqueue_fd);
210
211	while ((kqueue_fd = kqueue ()) < 0)
212	syserr ("(libev) kqueue");
213
214	fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC);
215
216	/* re-register interest in fds */
217	fd_rearm_all (EV_A);
218	}
219