libev/ev_kqueue.c

/*
 * libev kqueue backend
 *
 * Copyright (c) 2007,2008,2009,2010,2011,2012,2013,2016,2019 Marc Alexander Lehmann <libev@schmorp.de>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, 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 OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License ("GPL") version 2 or any later version,
 * in which case the provisions of the GPL are applicable instead of
 * the above. If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the BSD license, indicate your decision
 * by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL. If you do not delete the
 * provisions above, a recipient may use your version of this file under
 * either the BSD or the GPL.
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/event.h>
#include <string.h>
#include <errno.h>

inline_speed
void
kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
{
  ++kqueue_changecnt;
  array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, array_needsize_noinit);

  EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
}

/* OS X at least needs this */
#ifndef EV_ENABLE
# define EV_ENABLE 0
#endif
#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 | EV_ENABLE, NOTE_EOF);

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

  EV_RELEASE_CB;
  EV_TS_SET (ts, timeout);
  res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
  EV_ACQUIRE_CB;
  kqueue_changecnt = 0;

  if (expect_false (res < 0))
    {
      if (errno != EINTR)
        ev_syserr ("(libev) kqueue 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_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
      kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
    }
}

inline_size
int
kqueue_init (EV_P_ int flags)
{
  /* initialize the kernel queue */
  kqueue_fd_pid = getpid ();
  if ((backend_fd = kqueue ()) < 0)
    return 0;

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

  backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
  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;
}

inline_size
void
kqueue_destroy (EV_P)
{
  ev_free (kqueue_events);
  ev_free (kqueue_changes);
}

inline_size
void
kqueue_fork (EV_P)
{
  /* some BSD kernels don't just destroy the kqueue itself,
   * but also close the fd, which isn't documented, and
   * impossible to support properly.
   * we remember the pid of the kqueue call and only close
   * the fd if the pid is still the same.
   * this leaks fds on sane kernels, but BSD interfaces are
   * notoriously buggy and rarely get fixed.
   */
  pid_t newpid = getpid ();

  if (newpid == kqueue_fd_pid)
    close (backend_fd);

  kqueue_fd_pid = newpid;
  while ((backend_fd = kqueue ()) < 0)
    ev_syserr ("(libev) kqueue");

  fcntl (backend_fd, F_SETFD, FD_CLOEXEC);

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

/* sys/event.h defines EV_ERROR */
#undef EV_ERROR

Revision:	1.58
Committed:	Sat Jun 22 22:18:39 2019 UTC (4 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.57:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.26	* libev kqueue backend
3			*
4	root	1.57	* Copyright (c) 2007,2008,2009,2010,2011,2012,2013,2016,2019 Marc Alexander Lehmann <libev@schmorp.de>
5	root	1.1	* All rights reserved.
6			*
7	root	1.33	* Redistribution and use in source and binary forms, with or without modifica-
8			* tion, are permitted provided that the following conditions are met:
9	root	1.48	*
10	root	1.33	* 1. Redistributions of source code must retain the above copyright notice,
11			* this list of conditions and the following disclaimer.
12	root	1.48	*
13	root	1.33	* 2. Redistributions in binary form must reproduce the above copyright
14			* notice, this list of conditions and the following disclaimer in the
15			* documentation and/or other materials provided with the distribution.
16	root	1.48	*
17	root	1.33	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26			* OF THE POSSIBILITY OF SUCH DAMAGE.
27	root	1.26	*
28	root	1.33	* Alternatively, the contents of this file may be used under the terms of
29			* the GNU General Public License ("GPL") version 2 or any later version,
30			* in which case the provisions of the GPL are applicable instead of
31			* the above. If you wish to allow the use of your version of this file
32			* only under the terms of the GPL and not to allow others to use your
33			* version of this file under the BSD license, indicate your decision
34			* by deleting the provisions above and replace them with the notice
35			* and other provisions required by the GPL. If you do not delete the
36			* provisions above, a recipient may use your version of this file under
37			* either the BSD or the GPL.
38	root	1.1	*/
39
40			#include <sys/types.h>
41			#include <sys/time.h>
42			#include <sys/event.h>
43			#include <string.h>
44			#include <errno.h>
45
46	root	1.56	inline_speed
47			void
48	root	1.6	kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
49	root	1.1	{
50	ayin	1.16	++kqueue_changecnt;
51	root	1.57	array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, array_needsize_noinit);
52	root	1.1
53	root	1.23	EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
54	root	1.1	}
55
56	root	1.42	/* OS X at least needs this */
57			#ifndef EV_ENABLE
58			# define EV_ENABLE 0
59			#endif
60	root	1.4	#ifndef NOTE_EOF
61			# define NOTE_EOF 0
62			#endif
63
64	root	1.1	static void
65	root	1.6	kqueue_modify (EV_P_ int fd, int oev, int nev)
66	root	1.1	{
67	root	1.22	if (oev != nev)
68			{
69			if (oev & EV_READ)
70			kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
71	root	1.14
72	root	1.22	if (oev & EV_WRITE)
73			kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
74			}
75	root	1.14
76	root	1.22	/* to detect close/reopen reliably, we have to re-add */
77			/* event requests even when oev == nev */
78	root	1.14
79			if (nev & EV_READ)
80	root	1.42	kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD \| EV_ENABLE, NOTE_EOF);
81	root	1.1
82	root	1.14	if (nev & EV_WRITE)
83	root	1.42	kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD \| EV_ENABLE, NOTE_EOF);
84	root	1.1	}
85
86			static void
87	root	1.6	kqueue_poll (EV_P_ ev_tstamp timeout)
88	root	1.1	{
89			int res, i;
90			struct timespec ts;
91
92	root	1.14	/* need to resize so there is enough space for errors */
93			if (kqueue_changecnt > kqueue_eventmax)
94			{
95			ev_free (kqueue_events);
96	root	1.28	kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_changecnt);
97	root	1.15	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
98	root	1.14	}
99
100	root	1.39	EV_RELEASE_CB;
101	root	1.47	EV_TS_SET (ts, timeout);
102	root	1.25	res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
103	root	1.39	EV_ACQUIRE_CB;
104	root	1.6	kqueue_changecnt = 0;
105	root	1.1
106	root	1.29	if (expect_false (res < 0))
107	root	1.48	{
108	root	1.9	if (errno != EINTR)
109	root	1.58	ev_syserr ("(libev) kqueue kevent");
110	root	1.9
111			return;
112	root	1.48	}
113	root	1.1
114			for (i = 0; i < res; ++i)
115			{
116	root	1.14	int fd = kqueue_events [i].ident;
117
118	root	1.24	if (expect_false (kqueue_events [i].flags & EV_ERROR))
119	root	1.1	{
120	sf-exg	1.44	int err = kqueue_events [i].data;
121	root	1.14
122			/* we are only interested in errors for fds that we are interested in :) */
123			if (anfds [fd].events)
124	sf-exg	1.44	{
125	root	1.14	if (err == ENOENT) /* resubmit changes on ENOENT */
126			kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
127			else if (err == EBADF) /* on EBADF, we re-check the fd */
128			{
129			if (fd_valid (fd))
130			kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
131			else
132			fd_kill (EV_A_ fd);
133			}
134			else /* on all other errors, we error out on the fd */
135			fd_kill (EV_A_ fd);
136	sf-exg	1.44	}
137	root	1.1	}
138			else
139	root	1.3	fd_event (
140	root	1.6	EV_A_
141	root	1.14	fd,
142	root	1.6	kqueue_events [i].filter == EVFILT_READ ? EV_READ
143			: kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
144	root	1.1	: 0
145			);
146			}
147
148	root	1.6	if (expect_false (res == kqueue_eventmax))
149	root	1.1	{
150	root	1.9	ev_free (kqueue_events);
151	root	1.28	kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
152	root	1.15	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
153	root	1.1	}
154			}
155
156	root	1.56	inline_size
157			int
158	root	1.6	kqueue_init (EV_P_ int flags)
159	root	1.1	{
160	root	1.54	/* initialize the kernel queue */
161			kqueue_fd_pid = getpid ();
162	root	1.25	if ((backend_fd = kqueue ()) < 0)
163	root	1.6	return 0;
164	root	1.1
165	root	1.25	fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
166	root	1.7
167	root	1.51	backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
168			backend_modify = kqueue_modify;
169			backend_poll = kqueue_poll;
170	root	1.1
171	root	1.26	kqueue_eventmax = 64; /* initial number of events receivable per poll */
172	root	1.15	kqueue_events = (struct kevent )ev_malloc (sizeof (struct kevent) kqueue_eventmax);
173	root	1.6
174	root	1.7	kqueue_changes = 0;
175			kqueue_changemax = 0;
176			kqueue_changecnt = 0;
177
178	root	1.20	return EVBACKEND_KQUEUE;
179	root	1.1	}
180
181	root	1.56	inline_size
182			void
183	root	1.7	kqueue_destroy (EV_P)
184			{
185	root	1.9	ev_free (kqueue_events);
186			ev_free (kqueue_changes);
187	root	1.7	}
188
189	root	1.56	inline_size
190			void
191	root	1.7	kqueue_fork (EV_P)
192			{
193	root	1.54	/* some BSD kernels don't just destroy the kqueue itself,
194			* but also close the fd, which isn't documented, and
195			* impossible to support properly.
196			* we remember the pid of the kqueue call and only close
197			* the fd if the pid is still the same.
198			* this leaks fds on sane kernels, but BSD interfaces are
199			* notoriously buggy and rarely get fixed.
200			*/
201			pid_t newpid = getpid ();
202	root	1.10
203	root	1.54	if (newpid == kqueue_fd_pid)
204			close (backend_fd);
205
206			kqueue_fd_pid = newpid;
207	root	1.25	while ((backend_fd = kqueue ()) < 0)
208	root	1.35	ev_syserr ("(libev) kqueue");
209	root	1.10
210	root	1.25	fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
211	root	1.7
212			/* re-register interest in fds */
213	root	1.8	fd_rearm_all (EV_A);
214	root	1.7	}
215
216	root	1.52	/* sys/event.h defines EV_ERROR */
217			#undef EV_ERROR
218