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/cvs/libev/ev_poll.c
Revision: 1.17
Committed: Wed Nov 28 11:15:55 2007 UTC (16 years, 11 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rel-1_71, rel-1_72, rel-1_5, rel-1_6
Changes since 1.16: +3 -3 lines
Log Message:
experimental, and likely broken, inotify support

File Contents

# Content
1 /*
2 * libev poll 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 void
35 pollidx_init (int *base, int count)
36 {
37 while (count--)
38 *base++ = -1;
39 }
40
41 static void
42 poll_modify (EV_P_ int fd, int oev, int nev)
43 {
44 int idx;
45
46 if (oev == nev)
47 return;
48
49 array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init);
50
51 idx = pollidxs [fd];
52
53 if (idx < 0) /* need to allocate a new pollfd */
54 {
55 pollidxs [fd] = idx = pollcnt++;
56 array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
57 polls [idx].fd = fd;
58 }
59
60 assert (polls [idx].fd == fd);
61
62 if (nev)
63 polls [idx].events =
64 (nev & EV_READ ? POLLIN : 0)
65 | (nev & EV_WRITE ? POLLOUT : 0);
66 else /* remove pollfd */
67 {
68 pollidxs [fd] = -1;
69
70 if (idx < --pollcnt)
71 {
72 polls [idx] = polls [pollcnt];
73 pollidxs [polls [idx].fd] = idx;
74 }
75 }
76 }
77
78 static void
79 poll_poll (EV_P_ ev_tstamp timeout)
80 {
81 int i;
82 int res = poll (polls, pollcnt, (int)ceil (timeout * 1000.));
83
84 if (res < 0)
85 {
86 if (errno == EBADF)
87 fd_ebadf (EV_A);
88 else if (errno == ENOMEM && !syserr_cb)
89 fd_enomem (EV_A);
90 else if (errno != EINTR)
91 syserr ("(libev) poll");
92
93 return;
94 }
95
96 for (i = 0; i < pollcnt; ++i)
97 if (polls [i].revents & POLLNVAL)
98 fd_kill (EV_A_ polls [i].fd);
99 else
100 fd_event (
101 EV_A_
102 polls [i].fd,
103 (polls [i].revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
104 | (polls [i].revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
105 );
106 }
107
108 int inline_size
109 poll_init (EV_P_ int flags)
110 {
111 backend_fudge = 1e-3; /* needed to compensate for select returning early, very conservative */
112 backend_modify = poll_modify;
113 backend_poll = poll_poll;
114
115 pollidxs = 0; pollidxmax = 0;
116 polls = 0; pollmax = 0; pollcnt = 0;
117
118 return EVBACKEND_POLL;
119 }
120
121 void inline_size
122 poll_destroy (EV_P)
123 {
124 ev_free (pollidxs);
125 ev_free (polls);
126 }
127