libev/ev_epoll.c

/*
 * libev epoll fd activity 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/epoll.h>

static int epoll_fd = -1;

static void
epoll_modify (int fd, int oev, int nev)
{
  int mode = nev ? oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD : EPOLL_CTL_DEL;

  struct epoll_event ev;
  ev.data.u64 = fd; /* use u64 to fully initialise the struct, for nicer strace etc. */
  ev.events =
      (nev & EV_READ ? EPOLLIN : 0)
      | (nev & EV_WRITE ? EPOLLOUT : 0);

  epoll_ctl (epoll_fd, mode, fd, &ev);
}

static void
epoll_postfork_child (void)
{
  int fd;

  epoll_fd = epoll_create (256);
  fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);

  /* re-register interest in fds */
  for (fd = 0; fd < anfdmax; ++fd)
    if (anfds [fd].events)//D
      epoll_modify (fd, EV_NONE, anfds [fd].events);
}

static struct epoll_event *events;
static int eventmax;

static void
epoll_poll (ev_tstamp timeout)
{
  int eventcnt = epoll_wait (epoll_fd, events, eventmax, ceil (timeout * 1000.));
  int i;

  if (eventcnt < 0)
    return;

  for (i = 0; i < eventcnt; ++i)
    fd_event (
      events [i].data.fd,
      (events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
      | (events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0)
    );

  /* if the receive array was full, increase its size */
  if (expect_false (eventcnt == eventmax))
    {
      free (events);
      eventmax = array_roundsize (events, eventmax << 1);
      events = malloc (sizeof (struct epoll_event) * eventmax);
    }
}

static void
epoll_init (int flags)
{
  epoll_fd = epoll_create (256);

  if (epoll_fd < 0)
    return;

  fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);

  ev_method     = EVMETHOD_EPOLL;
  method_fudge  = 1e-3; /* needed to compensate for epoll returning early */
  method_modify = epoll_modify;
  method_poll   = epoll_poll;

  eventmax = 64; /* intiial number of events receivable per poll */
  events = malloc (sizeof (struct epoll_event) * eventmax);
}

Revision:	1.11
Committed:	Sat Nov 3 10:37:29 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.10:	+1 -1 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* libev epoll fd activity backend
3	*
4	* Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
5	* All rights reserved.
6	*
7	* Redistribution and use in source and binary forms, with or without
8	* 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	*
14	* * 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	*
19	* 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	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28	* (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	*/
31
32	#include <sys/epoll.h>
33
34	static int epoll_fd = -1;
35
36	static void
37	epoll_modify (int fd, int oev, int nev)
38	{
39	int mode = nev ? oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD : EPOLL_CTL_DEL;
40
41	struct epoll_event ev;
42	ev.data.u64 = fd; /* use u64 to fully initialise the struct, for nicer strace etc. */
43	ev.events =
44	(nev & EV_READ ? EPOLLIN : 0)
45	\| (nev & EV_WRITE ? EPOLLOUT : 0);
46
47	epoll_ctl (epoll_fd, mode, fd, &ev);
48	}
49
50	static void
51	epoll_postfork_child (void)
52	{
53	int fd;
54
55	epoll_fd = epoll_create (256);
56	fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
57
58	/* re-register interest in fds */
59	for (fd = 0; fd < anfdmax; ++fd)
60	if (anfds [fd].events)//D
61	epoll_modify (fd, EV_NONE, anfds [fd].events);
62	}
63
64	static struct epoll_event *events;
65	static int eventmax;
66
67	static void
68	epoll_poll (ev_tstamp timeout)
69	{
70	int eventcnt = epoll_wait (epoll_fd, events, eventmax, ceil (timeout * 1000.));
71	int i;
72
73	if (eventcnt < 0)
74	return;
75
76	for (i = 0; i < eventcnt; ++i)
77	fd_event (
78	events [i].data.fd,
79	(events [i].events & (EPOLLOUT \| EPOLLERR \| EPOLLHUP) ? EV_WRITE : 0)
80	\| (events [i].events & (EPOLLIN \| EPOLLERR \| EPOLLHUP) ? EV_READ : 0)
81	);
82
83	/* if the receive array was full, increase its size */
84	if (expect_false (eventcnt == eventmax))
85	{
86	free (events);
87	eventmax = array_roundsize (events, eventmax << 1);
88	events = malloc (sizeof (struct epoll_event) * eventmax);
89	}
90	}
91
92	static void
93	epoll_init (int flags)
94	{
95	epoll_fd = epoll_create (256);
96
97	if (epoll_fd < 0)
98	return;
99
100	fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
101
102	ev_method = EVMETHOD_EPOLL;
103	method_fudge = 1e-3; /* needed to compensate for epoll returning early */
104	method_modify = epoll_modify;
105	method_poll = epoll_poll;
106
107	eventmax = 64; /* intiial number of events receivable per poll */
108	events = malloc (sizeof (struct epoll_event) * eventmax);
109	}
110