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/cvs/libev/ev_poll.c
Revision: 1.23
Committed: Thu Apr 10 06:48:12 2008 UTC (16 years, 3 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rel-3_3
Changes since 1.22: +17 -12 lines
Log Message:
*** empty log message ***

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 modifica-
8 * tion, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * 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 *
17 * 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 *
28 * 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 */
39
40 #include <poll.h>
41
42 void inline_size
43 pollidx_init (int *base, int count)
44 {
45 while (count--)
46 *base++ = -1;
47 }
48
49 static void
50 poll_modify (EV_P_ int fd, int oev, int nev)
51 {
52 int idx;
53
54 if (oev == nev)
55 return;
56
57 array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init);
58
59 idx = pollidxs [fd];
60
61 if (idx < 0) /* need to allocate a new pollfd */
62 {
63 pollidxs [fd] = idx = pollcnt++;
64 array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
65 polls [idx].fd = fd;
66 }
67
68 assert (polls [idx].fd == fd);
69
70 if (nev)
71 polls [idx].events =
72 (nev & EV_READ ? POLLIN : 0)
73 | (nev & EV_WRITE ? POLLOUT : 0);
74 else /* remove pollfd */
75 {
76 pollidxs [fd] = -1;
77
78 if (expect_true (idx < --pollcnt))
79 {
80 polls [idx] = polls [pollcnt];
81 pollidxs [polls [idx].fd] = idx;
82 }
83 }
84 }
85
86 static void
87 poll_poll (EV_P_ ev_tstamp timeout)
88 {
89 struct pollfd *p;
90 int res = poll (polls, pollcnt, (int)ceil (timeout * 1000.));
91
92 if (expect_false (res < 0))
93 {
94 if (errno == EBADF)
95 fd_ebadf (EV_A);
96 else if (errno == ENOMEM && !syserr_cb)
97 fd_enomem (EV_A);
98 else if (errno != EINTR)
99 syserr ("(libev) poll");
100 }
101
102 for (p = polls; res; ++p)
103 if (expect_false (p->revents)) /* this expect is debatable */
104 {
105 --res;
106
107 if (expect_false (p->revents & POLLNVAL))
108 fd_kill (EV_A_ p->fd);
109 else
110 fd_event (
111 EV_A_
112 p->fd,
113 (p->revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
114 | (p->revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
115 );
116 }
117 }
118
119 int inline_size
120 poll_init (EV_P_ int flags)
121 {
122 backend_fudge = 0.; /* posix says this is zero */
123 backend_modify = poll_modify;
124 backend_poll = poll_poll;
125
126 pollidxs = 0; pollidxmax = 0;
127 polls = 0; pollmax = 0; pollcnt = 0;
128
129 return EVBACKEND_POLL;
130 }
131
132 void inline_size
133 poll_destroy (EV_P)
134 {
135 ev_free (pollidxs);
136 ev_free (polls);
137 }
138