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/cvs/libev/ev_poll.c
Revision: 1.31
Committed: Sun Jul 19 04:11:27 2009 UTC (15 years ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rel-3_9, rel-3_8
Changes since 1.30: +1 -1 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 /*
2 * libev poll fd activity backend
3 *
4 * Copyright (c) 2007,2008,2009 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 /* consider using memset (.., -1, ...), which is pratically guarenteed
46 * to work on all systems implementing poll */
47 while (count--)
48 *base++ = -1;
49 }
50
51 static void
52 poll_modify (EV_P_ int fd, int oev, int nev)
53 {
54 int idx;
55
56 if (oev == nev)
57 return;
58
59 array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init);
60
61 idx = pollidxs [fd];
62
63 if (idx < 0) /* need to allocate a new pollfd */
64 {
65 pollidxs [fd] = idx = pollcnt++;
66 array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
67 polls [idx].fd = fd;
68 }
69
70 assert (polls [idx].fd == fd);
71
72 if (nev)
73 polls [idx].events =
74 (nev & EV_READ ? POLLIN : 0)
75 | (nev & EV_WRITE ? POLLOUT : 0);
76 else /* remove pollfd */
77 {
78 pollidxs [fd] = -1;
79
80 if (expect_true (idx < --pollcnt))
81 {
82 polls [idx] = polls [pollcnt];
83 pollidxs [polls [idx].fd] = idx;
84 }
85 }
86 }
87
88 static void
89 poll_poll (EV_P_ ev_tstamp timeout)
90 {
91 struct pollfd *p;
92 int res;
93
94 EV_RELEASE_CB;
95 res = poll (polls, pollcnt, (int)ceil (timeout * 1000.));
96 EV_ACQUIRE_CB;
97
98 if (expect_false (res < 0))
99 {
100 if (errno == EBADF)
101 fd_ebadf (EV_A);
102 else if (errno == ENOMEM && !syserr_cb)
103 fd_enomem (EV_A);
104 else if (errno != EINTR)
105 ev_syserr ("(libev) poll");
106 }
107 else
108 for (p = polls; res; ++p)
109 if (expect_false (p->revents)) /* this expect is debatable */
110 {
111 --res;
112
113 if (expect_false (p->revents & POLLNVAL))
114 fd_kill (EV_A_ p->fd);
115 else
116 fd_event (
117 EV_A_
118 p->fd,
119 (p->revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
120 | (p->revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
121 );
122 }
123 }
124
125 int inline_size
126 poll_init (EV_P_ int flags)
127 {
128 backend_fudge = 0.; /* posix says this is zero */
129 backend_modify = poll_modify;
130 backend_poll = poll_poll;
131
132 pollidxs = 0; pollidxmax = 0;
133 polls = 0; pollmax = 0; pollcnt = 0;
134
135 return EVBACKEND_POLL;
136 }
137
138 void inline_size
139 poll_destroy (EV_P)
140 {
141 ev_free (pollidxs);
142 ev_free (polls);
143 }
144