libev/ev_kqueue.c

/*
 * libev kqueue backend
 *
 * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 COPYRIGHT
 * OWNER OR CONTRIBUTORS 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 (backend_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;

          /* 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 ((backend_fd = kqueue ()) < 0)
    return 0;

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

  /* fudge *might* be zero from the documentation, but bsd docs are notoriously wrong */
  backend_fudge  = 1e-3; /* needed to compensate for kevent returning early */
  backend_modify = kqueue_modify;
  backend_poll   = kqueue_poll;

  kqueue_eventmax = 64; /* initial 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 (backend_fd);

  ev_free (kqueue_events);
  ev_free (kqueue_changes);
}

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

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

  fcntl (backend_fd, F_SETFD, FD_CLOEXEC);

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

Revision:	1.26
Committed:	Mon Nov 26 08:04:03 2007 UTC (16 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_4
Changes since 1.25:	+23 -49 lines
Log Message:	remove libevent code (a comment and the kevent test) from ev_kqueue and relicense under libev license
#	User	Rev	Content
1	root	1.1	/*
2	root	1.26	* libev kqueue backend
3			*
4			* Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
5	root	1.1	* All rights reserved.
6			*
7			* Redistribution and use in source and binary forms, with or without
8	root	1.26	* modification, are permitted provided that the following conditions are
9			* met:
10			*
11			* * Redistributions of source code must retain the above copyright
12			* notice, this list of conditions and the following disclaimer.
13	root	1.1	*
14	root	1.26	* * Redistributions in binary form must reproduce the above
15			* copyright notice, this list of conditions and the following
16			* disclaimer in the documentation and/or other materials provided
17			* with the distribution.
18	root	1.1	*
19	root	1.26	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20			* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21			* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22			* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23			* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25			* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26	root	1.1	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28	root	1.26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29			* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30	root	1.1	*/
31
32			#include <sys/types.h>
33			#include <sys/time.h>
34			#include <sys/queue.h>
35			#include <sys/event.h>
36			#include <string.h>
37			#include <errno.h>
38
39			static void
40	root	1.6	kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
41	root	1.1	{
42			struct kevent *ke;
43
44	ayin	1.16	++kqueue_changecnt;
45	root	1.17	array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
46	root	1.1
47	root	1.23	EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
48	root	1.1	}
49
50	root	1.4	#ifndef NOTE_EOF
51			# define NOTE_EOF 0
52			#endif
53
54	root	1.1	static void
55	root	1.6	kqueue_modify (EV_P_ int fd, int oev, int nev)
56	root	1.1	{
57	root	1.22	if (oev != nev)
58			{
59			if (oev & EV_READ)
60			kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
61	root	1.14
62	root	1.22	if (oev & EV_WRITE)
63			kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
64			}
65	root	1.14
66	root	1.22	/* to detect close/reopen reliably, we have to re-add */
67			/* event requests even when oev == nev */
68	root	1.14
69			if (nev & EV_READ)
70	root	1.22	kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD, NOTE_EOF);
71	root	1.1
72	root	1.14	if (nev & EV_WRITE)
73			kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
74	root	1.1	}
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	root	1.14	/* need to resize so there is enough space for errors */
83			if (kqueue_changecnt > kqueue_eventmax)
84			{
85			ev_free (kqueue_events);
86			kqueue_eventmax = array_roundsize (struct kevent, kqueue_changecnt);
87	root	1.15	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
88	root	1.14	}
89
90	root	1.1	ts.tv_sec = (time_t)timeout;
91	root	1.18	ts.tv_nsec = (long)((timeout - (ev_tstamp)ts.tv_sec) * 1e9);
92	root	1.25	res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
93	root	1.6	kqueue_changecnt = 0;
94	root	1.1
95			if (res < 0)
96	root	1.9	{
97			if (errno != EINTR)
98	root	1.10	syserr ("(libev) kevent");
99	root	1.9
100			return;
101			}
102	root	1.1
103			for (i = 0; i < res; ++i)
104			{
105	root	1.14	int fd = kqueue_events [i].ident;
106
107	root	1.24	if (expect_false (kqueue_events [i].flags & EV_ERROR))
108	root	1.1	{
109	root	1.14	int err = kqueue_events [i].data;
110
111			/* we are only interested in errors for fds that we are interested in :) */
112			if (anfds [fd].events)
113			{
114			if (err == ENOENT) /* resubmit changes on ENOENT */
115			kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
116			else if (err == EBADF) /* on EBADF, we re-check the fd */
117			{
118			if (fd_valid (fd))
119			kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
120			else
121			fd_kill (EV_A_ fd);
122			}
123			else /* on all other errors, we error out on the fd */
124			fd_kill (EV_A_ fd);
125			}
126	root	1.1	}
127			else
128	root	1.3	fd_event (
129	root	1.6	EV_A_
130	root	1.14	fd,
131	root	1.6	kqueue_events [i].filter == EVFILT_READ ? EV_READ
132			: kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
133	root	1.1	: 0
134			);
135			}
136
137	root	1.6	if (expect_false (res == kqueue_eventmax))
138	root	1.1	{
139	root	1.9	ev_free (kqueue_events);
140	root	1.14	kqueue_eventmax = array_roundsize (struct kevent, kqueue_eventmax << 1);
141	root	1.15	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
142	root	1.1	}
143			}
144
145	root	1.6	static int
146			kqueue_init (EV_P_ int flags)
147	root	1.1	{
148	root	1.2	struct kevent ch, ev;
149
150	root	1.1	/* Initalize the kernel queue */
151	root	1.25	if ((backend_fd = kqueue ()) < 0)
152	root	1.6	return 0;
153	root	1.1
154	root	1.25	fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
155	root	1.7
156	root	1.26	/* fudge might be zero from the documentation, but bsd docs are notoriously wrong */
157	root	1.21	backend_fudge = 1e-3; /* needed to compensate for kevent returning early */
158			backend_modify = kqueue_modify;
159			backend_poll = kqueue_poll;
160	root	1.1
161	root	1.26	kqueue_eventmax = 64; /* initial number of events receivable per poll */
162	root	1.15	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
163	root	1.6
164	root	1.7	kqueue_changes = 0;
165			kqueue_changemax = 0;
166			kqueue_changecnt = 0;
167
168	root	1.20	return EVBACKEND_KQUEUE;
169	root	1.1	}
170
171	root	1.7	static void
172			kqueue_destroy (EV_P)
173			{
174	root	1.25	close (backend_fd);
175	root	1.7
176	root	1.9	ev_free (kqueue_events);
177			ev_free (kqueue_changes);
178	root	1.7	}
179
180			static void
181			kqueue_fork (EV_P)
182			{
183	root	1.25	close (backend_fd);
184	root	1.10
185	root	1.25	while ((backend_fd = kqueue ()) < 0)
186	root	1.11	syserr ("(libev) kqueue");
187	root	1.10
188	root	1.25	fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
189	root	1.7
190			/* re-register interest in fds */
191	root	1.8	fd_rearm_all (EV_A);
192	root	1.7	}
193