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/cvs/libev/ev_poll.c
Revision: 1.23
Committed: Thu Apr 10 06:48:12 2008 UTC (16 years, 7 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

# User Rev Content
1 root 1.1 /*
2 root 1.17 * libev poll fd activity backend
3 root 1.1 *
4     * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
5     * All rights reserved.
6     *
7 root 1.21 * 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 root 1.1 *
28 root 1.21 * 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 root 1.1 */
39    
40 root 1.2 #include <poll.h>
41 root 1.1
42 root 1.18 void inline_size
43 root 1.2 pollidx_init (int *base, int count)
44 root 1.1 {
45 root 1.2 while (count--)
46     *base++ = -1;
47 root 1.1 }
48    
49     static void
50 root 1.3 poll_modify (EV_P_ int fd, int oev, int nev)
51 root 1.1 {
52 root 1.2 int idx;
53 root 1.6
54     if (oev == nev)
55     return;
56    
57 root 1.9 array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init);
58 root 1.1
59 root 1.2 idx = pollidxs [fd];
60    
61     if (idx < 0) /* need to allocate a new pollfd */
62     {
63 root 1.10 pollidxs [fd] = idx = pollcnt++;
64 root 1.14 array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
65 root 1.2 polls [idx].fd = fd;
66     }
67 root 1.1
68 root 1.10 assert (polls [idx].fd == fd);
69    
70 root 1.2 if (nev)
71     polls [idx].events =
72     (nev & EV_READ ? POLLIN : 0)
73     | (nev & EV_WRITE ? POLLOUT : 0);
74     else /* remove pollfd */
75     {
76 root 1.10 pollidxs [fd] = -1;
77    
78 root 1.18 if (expect_true (idx < --pollcnt))
79 root 1.2 {
80     polls [idx] = polls [pollcnt];
81     pollidxs [polls [idx].fd] = idx;
82     }
83     }
84 root 1.1 }
85    
86     static void
87 root 1.3 poll_poll (EV_P_ ev_tstamp timeout)
88 root 1.1 {
89 root 1.23 struct pollfd *p;
90 root 1.11 int res = poll (polls, pollcnt, (int)ceil (timeout * 1000.));
91 root 1.1
92 root 1.18 if (expect_false (res < 0))
93 root 1.1 {
94 root 1.2 if (errno == EBADF)
95 root 1.3 fd_ebadf (EV_A);
96 root 1.7 else if (errno == ENOMEM && !syserr_cb)
97 root 1.3 fd_enomem (EV_A);
98 root 1.7 else if (errno != EINTR)
99 root 1.8 syserr ("(libev) poll");
100 root 1.1 }
101 root 1.23
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 root 1.1 }
118    
119 root 1.17 int inline_size
120 root 1.3 poll_init (EV_P_ int flags)
121 root 1.1 {
122 root 1.20 backend_fudge = 0.; /* posix says this is zero */
123 root 1.16 backend_modify = poll_modify;
124     backend_poll = poll_poll;
125 root 1.3
126 root 1.4 pollidxs = 0; pollidxmax = 0;
127 root 1.5 polls = 0; pollmax = 0; pollcnt = 0;
128 root 1.4
129 root 1.15 return EVBACKEND_POLL;
130 root 1.1 }
131 root 1.4
132 root 1.17 void inline_size
133 root 1.4 poll_destroy (EV_P)
134     {
135 root 1.7 ev_free (pollidxs);
136     ev_free (polls);
137 root 1.4 }
138 root 1.9