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;

  array_needsize (kqueue_changes, kqueue_changemax, ++kqueue_changecnt, );

  ke = &kqueue_changes [kqueue_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 (EV_P_ 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_P_ 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 (kqueue_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
  kqueue_changecnt = 0;

  if (res < 0)
    return;

  for (i = 0; i < res; ++i)
    {
      if (kqueue_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 (kqueue_events [i].data == EBADF)
            fd_kill (EV_A_ kqueue_events [i].ident);
        }
      else
        fd_event (
          EV_A_
          kqueue_events [i].ident,
          kqueue_events [i].filter == EVFILT_READ ? EV_READ
          : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
          : 0
        );
    }

  if (expect_false (res == kqueue_eventmax))
    {
      free (kqueue_events);
      kqueue_eventmax = array_roundsize (kqueue_events, kqueue_eventmax << 1);
      kqueue_events = 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;
    }

  method_fudge  = 1e-3; /* needed to compensate for kevent returning early */
  method_modify = kqueue_modify;
  method_poll   = kqueue_poll;

  kqueue_eventmax = 64; /* intiial number of events receivable per poll */
  kqueue_events = malloc (sizeof (struct kevent) * kqueue_eventmax);

  kqueue_changes   = 0;
  kqueue_changemax = 0;
  kqueue_changecnt = 0;

  return EVMETHOD_KQUEUE;
}

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

  free (kqueue_events);
  free (kqueue_changes);
}

static void
kqueue_fork (EV_P)
{
  kqueue_fd = kqueue ();
  fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC);

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

Revision:	1.8
Committed:	Sun Nov 4 18:29:44 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.7:	+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	array_needsize (kqueue_changes, kqueue_changemax, ++kqueue_changecnt, );
43
44	ke = &kqueue_changes [kqueue_changecnt - 1];
45	memset (ke, 0, sizeof (struct kevent));
46	ke->ident = fd;
47	ke->filter = filter;
48	ke->flags = flags;
49	ke->fflags = fflags;
50	}
51
52	#ifndef NOTE_EOF
53	# define NOTE_EOF 0
54	#endif
55
56	static void
57	kqueue_modify (EV_P_ int fd, int oev, int nev)
58	{
59	if ((oev ^ nev) & EV_READ)
60	{
61	if (nev & EV_READ)
62	kqueue_change (fd, EVFILT_READ, EV_ADD, NOTE_EOF);
63	else
64	kqueue_change (fd, EVFILT_READ, EV_DELETE, 0);
65	}
66
67	if ((oev ^ nev) & EV_WRITE)
68	{
69	if (nev & EV_WRITE)
70	kqueue_change (fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
71	else
72	kqueue_change (fd, EVFILT_WRITE, EV_DELETE, 0);
73	}
74	}
75
76	static void
77	kqueue_poll (EV_P_ ev_tstamp timeout)
78	{
79	int res, i;
80	struct timespec ts;
81
82	ts.tv_sec = (time_t)timeout;
83	ts.tv_nsec = (long)(timeout - (ev_tstamp)ts.tv_sec) * 1e9;
84	res = kevent (kqueue_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
85	kqueue_changecnt = 0;
86
87	if (res < 0)
88	return;
89
90	for (i = 0; i < res; ++i)
91	{
92	if (kqueue_events [i].flags & EV_ERROR)
93	{
94	/*
95	* Error messages that can happen, when a delete fails.
96	* EBADF happens when the file discriptor has been
97	* closed,
98	* ENOENT when the file discriptor was closed and
99	* then reopened.
100	* EINVAL for some reasons not understood; EINVAL
101	* should not be returned ever; but FreeBSD does :-\
102	* An error is also indicated when a callback deletes
103	* an event we are still processing. In that case
104	* the data field is set to ENOENT.
105	*/
106	if (kqueue_events [i].data == EBADF)
107	fd_kill (EV_A_ kqueue_events [i].ident);
108	}
109	else
110	fd_event (
111	EV_A_
112	kqueue_events [i].ident,
113	kqueue_events [i].filter == EVFILT_READ ? EV_READ
114	: kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
115	: 0
116	);
117	}
118
119	if (expect_false (res == kqueue_eventmax))
120	{
121	free (kqueue_events);
122	kqueue_eventmax = array_roundsize (kqueue_events, kqueue_eventmax << 1);
123	kqueue_events = malloc (sizeof (struct kevent) * kqueue_eventmax);
124	}
125	}
126
127	static int
128	kqueue_init (EV_P_ int flags)
129	{
130	struct kevent ch, ev;
131
132	/* Initalize the kernel queue */
133	if ((kqueue_fd = kqueue ()) < 0)
134	return 0;
135
136	fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
137
138	/* Check for Mac OS X kqueue bug. */
139	ch.ident = -1;
140	ch.filter = EVFILT_READ;
141	ch.flags = EV_ADD;
142
143	/*
144	* If kqueue works, then kevent will succeed, and it will
145	* stick an error in ev. If kqueue is broken, then
146	* kevent will fail.
147	*/
148	if (kevent (kqueue_fd, &ch, 1, &ev, 1, 0) != 1
149	\|\| ev.ident != -1
150	\|\| ev.flags != EV_ERROR)
151	{
152	/* detected broken kqueue */
153	close (kqueue_fd);
154	return 0;
155	}
156
157	method_fudge = 1e-3; /* needed to compensate for kevent returning early */
158	method_modify = kqueue_modify;
159	method_poll = kqueue_poll;
160
161	kqueue_eventmax = 64; /* intiial number of events receivable per poll */
162	kqueue_events = malloc (sizeof (struct kevent) * kqueue_eventmax);
163
164	kqueue_changes = 0;
165	kqueue_changemax = 0;
166	kqueue_changecnt = 0;
167
168	return EVMETHOD_KQUEUE;
169	}
170
171	static void
172	kqueue_destroy (EV_P)
173	{
174	close (kqueue_fd);
175
176	free (kqueue_events);
177	free (kqueue_changes);
178	}
179
180	static void
181	kqueue_fork (EV_P)
182	{
183	kqueue_fd = kqueue ();
184	fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC);
185
186	/* re-register interest in fds */
187	fd_rearm_all (EV_A);
188	}
189