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 (struct kevent, 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 (EV_A_ fd, EVFILT_READ, EV_ADD, NOTE_EOF);
      else
        kqueue_change (EV_A_ fd, EVFILT_READ, EV_DELETE, 0);
    }

  if ((oev ^ nev) & EV_WRITE)
    {
      if (nev & EV_WRITE)
        kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
      else
        kqueue_change (EV_A_ 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)
    { 
      if (errno != EINTR)
        syserr ("(libev) kevent");

      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))
    {
      ev_free (kqueue_events);
      kqueue_eventmax = array_roundsize (kqueue_events, kqueue_eventmax << 1);
      kqueue_events = 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;
    }

  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 = ev_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);

  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:	1.13
Committed:	Tue Nov 6 17:20:42 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.12:	+4 -4 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 (struct kevent, 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 (EV_A_ fd, EVFILT_READ, EV_ADD, NOTE_EOF);
63	else
64	kqueue_change (EV_A_ fd, EVFILT_READ, EV_DELETE, 0);
65	}
66
67	if ((oev ^ nev) & EV_WRITE)
68	{
69	if (nev & EV_WRITE)
70	kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
71	else
72	kqueue_change (EV_A_ 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	{
89	if (errno != EINTR)
90	syserr ("(libev) kevent");
91
92	return;
93	}
94
95	for (i = 0; i < res; ++i)
96	{
97	if (kqueue_events [i].flags & EV_ERROR)
98	{
99	/*
100	* Error messages that can happen, when a delete fails.
101	* EBADF happens when the file discriptor has been
102	* closed,
103	* ENOENT when the file discriptor was closed and
104	* then reopened.
105	* EINVAL for some reasons not understood; EINVAL
106	* should not be returned ever; but FreeBSD does :-\
107	* An error is also indicated when a callback deletes
108	* an event we are still processing. In that case
109	* the data field is set to ENOENT.
110	*/
111	if (kqueue_events [i].data == EBADF)
112	fd_kill (EV_A_ kqueue_events [i].ident);
113	}
114	else
115	fd_event (
116	EV_A_
117	kqueue_events [i].ident,
118	kqueue_events [i].filter == EVFILT_READ ? EV_READ
119	: kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
120	: 0
121	);
122	}
123
124	if (expect_false (res == kqueue_eventmax))
125	{
126	ev_free (kqueue_events);
127	kqueue_eventmax = array_roundsize (kqueue_events, kqueue_eventmax << 1);
128	kqueue_events = ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
129	}
130	}
131
132	static int
133	kqueue_init (EV_P_ int flags)
134	{
135	struct kevent ch, ev;
136
137	/* Initalize the kernel queue */
138	if ((kqueue_fd = kqueue ()) < 0)
139	return 0;
140
141	fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
142
143	/* Check for Mac OS X kqueue bug. */
144	ch.ident = -1;
145	ch.filter = EVFILT_READ;
146	ch.flags = EV_ADD;
147
148	/*
149	* If kqueue works, then kevent will succeed, and it will
150	* stick an error in ev. If kqueue is broken, then
151	* kevent will fail.
152	*/
153	if (kevent (kqueue_fd, &ch, 1, &ev, 1, 0) != 1
154	\|\| ev.ident != -1
155	\|\| ev.flags != EV_ERROR)
156	{
157	/* detected broken kqueue */
158	close (kqueue_fd);
159	return 0;
160	}
161
162	method_fudge = 1e-3; /* needed to compensate for kevent returning early */
163	method_modify = kqueue_modify;
164	method_poll = kqueue_poll;
165
166	kqueue_eventmax = 64; /* intiial number of events receivable per poll */
167	kqueue_events = ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
168
169	kqueue_changes = 0;
170	kqueue_changemax = 0;
171	kqueue_changecnt = 0;
172
173	return EVMETHOD_KQUEUE;
174	}
175
176	static void
177	kqueue_destroy (EV_P)
178	{
179	close (kqueue_fd);
180
181	ev_free (kqueue_events);
182	ev_free (kqueue_changes);
183	}
184
185	static void
186	kqueue_fork (EV_P)
187	{
188	close (kqueue_fd);
189
190	while ((kqueue_fd = kqueue ()) < 0)
191	syserr ("(libev) kqueue");
192
193	fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC);
194
195	/* re-register interest in fds */
196	fd_rearm_all (EV_A);
197	}
198