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/cvs/libev/ev_poll.c
Revision: 1.2
Committed: Fri Nov 2 16:54:35 2007 UTC (17 years, 1 month ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.1: +54 -56 lines
Log Message:
implement poll method, handle enomem by closing a 'random' fd

File Contents

# 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 <poll.h>
33
34 static struct pollfd *polls;
35 static int pollmax, pollcnt;
36 static int *pollidxs; /* maps fds into structure indices */
37 static int pollidxmax;
38
39 static void
40 pollidx_init (int *base, int count)
41 {
42 while (count--)
43 *base++ = -1;
44 }
45
46 static void
47 poll_modify (int fd, int oev, int nev)
48 {
49 int idx;
50 array_needsize (pollidxs, pollidxmax, fd + 1, pollidx_init);
51
52 idx = pollidxs [fd];
53
54 if (idx < 0) /* need to allocate a new pollfd */
55 {
56 idx = pollcnt++;
57 array_needsize (polls, pollmax, pollcnt, );
58 polls [idx].fd = fd;
59 }
60
61 if (nev)
62 polls [idx].events =
63 (nev & EV_READ ? POLLIN : 0)
64 | (nev & EV_WRITE ? POLLOUT : 0);
65 else /* remove pollfd */
66 {
67 if (idx < pollcnt--)
68 {
69 pollidxs [fd] = -1;
70 polls [idx] = polls [pollcnt];
71 pollidxs [polls [idx].fd] = idx;
72 }
73 }
74 }
75
76 static void
77 poll_poll (ev_tstamp timeout)
78 {
79 int res = poll (polls, pollcnt, ceil (timeout * 1000.));
80
81 if (res > 0)
82 {
83 int i;
84
85 for (i = 0; i < pollcnt; ++i)
86 fd_event (
87 polls [i].fd,
88 (polls [i].revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
89 | (polls [i].revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
90 );
91 }
92 else if (res < 0)
93 {
94 if (errno == EBADF)
95 fd_ebadf ();
96 else if (errno == ENOMEM)
97 fd_enomem ();
98 }
99 }
100
101 static void
102 poll_init (int flags)
103 {
104 ev_method = EVMETHOD_POLL;
105 method_fudge = 1e-3; /* needed to compensate for select returning early, very conservative */
106 method_modify = poll_modify;
107 method_poll = poll_poll;
108 }