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;

  /* 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);

  return EVMETHOD_KQUEUE;
}

Revision:	1.6
Committed:	Sat Nov 3 21:58:51 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.5:	+29 -33 lines
Log Message:	prepare for multiple bases
#	User	Rev	Content
1	root	1.1	/*
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	root	1.6	kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
39	root	1.1	{
40			struct kevent *ke;
41
42	root	1.6	array_needsize (kqueue_changes, kqueue_changemax, ++kqueue_changecnt, );
43	root	1.1
44	root	1.6	ke = &kqueue_changes [kqueue_changecnt - 1];
45	root	1.1	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	root	1.4	#ifndef NOTE_EOF
53			# define NOTE_EOF 0
54			#endif
55
56	root	1.1	static void
57	root	1.6	kqueue_modify (EV_P_ int fd, int oev, int nev)
58	root	1.1	{
59	root	1.4	if ((oev ^ nev) & EV_READ)
60	root	1.1	{
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	root	1.4	if ((oev ^ nev) & EV_WRITE)
68	root	1.1	{
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	root	1.6	kqueue_poll (EV_P_ ev_tstamp timeout)
78	root	1.1	{
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	root	1.6	res = kevent (kqueue_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
85			kqueue_changecnt = 0;
86	root	1.1
87			if (res < 0)
88			return;
89
90			for (i = 0; i < res; ++i)
91			{
92	root	1.6	if (kqueue_events [i].flags & EV_ERROR)
93	root	1.1	{
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	root	1.6	if (kqueue_events [i].data == EBADF)
107			fd_kill (EV_A_ kqueue_events [i].ident);
108	root	1.1	}
109			else
110	root	1.3	fd_event (
111	root	1.6	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	root	1.1	: 0
116			);
117			}
118
119	root	1.6	if (expect_false (res == kqueue_eventmax))
120	root	1.1	{
121	root	1.6	free (kqueue_events);
122			kqueue_eventmax = array_roundsize (kqueue_events, kqueue_eventmax << 1);
123			kqueue_events = malloc (sizeof (struct kevent) * kqueue_eventmax);
124	root	1.1	}
125			}
126
127	root	1.6	static int
128			kqueue_init (EV_P_ int flags)
129	root	1.1	{
130	root	1.2	struct kevent ch, ev;
131
132	root	1.1	/* Initalize the kernel queue */
133	root	1.6	if ((kqueue_fd = kqueue ()) < 0)
134			return 0;
135	root	1.1
136	root	1.2	/* Check for Mac OS X kqueue bug. */
137			ch.ident = -1;
138			ch.filter = EVFILT_READ;
139			ch.flags = EV_ADD;
140	root	1.1
141			/*
142			* If kqueue works, then kevent will succeed, and it will
143	root	1.4	* stick an error in ev. If kqueue is broken, then
144	root	1.1	* kevent will fail.
145			*/
146	root	1.6	if (kevent (kqueue_fd, &ch, 1, &ev, 1, 0) != 1
147	root	1.2	\|\| ev.ident != -1
148			\|\| ev.flags != EV_ERROR)
149	root	1.1	{
150			/* detected broken kqueue */
151	root	1.6	close (kqueue_fd);
152			return 0;
153	root	1.1	}
154
155			method_fudge = 1e-3; /* needed to compensate for kevent returning early */
156	root	1.5	method_modify = kqueue_modify;
157			method_poll = kqueue_poll;
158	root	1.1
159	root	1.6	kqueue_eventmax = 64; /* intiial number of events receivable per poll */
160			kqueue_events = malloc (sizeof (struct kevent) * kqueue_eventmax);
161
162			return EVMETHOD_KQUEUE;
163	root	1.1	}
164