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/cvs/libev/ev_epoll.c
Revision: 1.6
Committed: Wed Oct 31 20:46:44 2007 UTC (16 years, 6 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.5: +7 -3 lines
Log Message:
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File Contents

# Content
1 /*
2 * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 * * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * * Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials provided
15 * with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * 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
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/epoll.h>
31
32 static int epoll_fd = -1;
33
34 static void
35 epoll_modify (int fd, int oev, int nev)
36 {
37 int mode = nev ? oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD : EPOLL_CTL_DEL;
38
39 struct epoll_event ev;
40 ev.data.fd = fd;
41 ev.events =
42 (nev & EV_READ ? EPOLLIN : 0)
43 | (nev & EV_WRITE ? EPOLLOUT : 0);
44
45 epoll_ctl (epoll_fd, mode, fd, &ev);
46 }
47
48 static void
49 epoll_postfork_child (void)
50 {
51 int fd;
52
53 epoll_fd = epoll_create (256);
54 fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
55
56 /* re-register interest in fds */
57 for (fd = 0; fd < anfdmax; ++fd)
58 if (anfds [fd].wev)
59 epoll_modify (fd, EV_NONE, anfds [fd].wev);
60 }
61
62 static struct epoll_event *events;
63 static int eventmax;
64
65 static void
66 epoll_poll (ev_tstamp timeout)
67 {
68 int eventcnt = epoll_wait (epoll_fd, events, eventmax, ceil (timeout * 1000.));
69 int i;
70
71 if (eventcnt < 0)
72 return;
73
74 for (i = 0; i < eventcnt; ++i)
75 fd_event (
76 events [i].data.fd,
77 (events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
78 | (events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0)
79 );
80
81 /* if the receive array was full, increase its size */
82 if (eventcnt == eventmax)
83 {
84 free (events);
85 eventmax += eventmax >> 1;
86 events = malloc (sizeof (struct epoll_event) * eventmax);
87 }
88 }
89
90 static void
91 epoll_init (int flags)
92 {
93 epoll_fd = epoll_create (256);
94
95 if (epoll_fd < 0)
96 return;
97
98 fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
99
100 ev_method = EVMETHOD_EPOLL;
101 method_fudge = 1e-3; /* needed to compensate for epoll returning early */
102 method_modify = epoll_modify;
103 method_poll = epoll_poll;
104
105 eventmax = 64; /* intiial number of events receivable per poll */
106 events = malloc (sizeof (struct epoll_event) * eventmax);
107 }
108