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/cvs/libev/ev_port.c
Revision: 1.34
Committed: Sat May 22 20:14:57 2021 UTC (3 years, 1 month ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: HEAD
Changes since 1.33: +5 -5 lines
Log Message:
replace soem urls

File Contents

# Content
1 /*
2 * libev solaris event port backend
3 *
4 * Copyright (c) 2007,2008,2009,2010,2011,2019 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 /* useful reading:
41 *
42 * https://archive.is/jN6Ck (random results)
43 * https://archive.is/bBikp (just totally broken)
44 * https://archive.is/eJhmu (manpage ETIME)
45 * https://archive.is/RbgYw (implementation ETIME)
46 * http://www.mail-archive.com/networking-discuss@opensolaris.org/msg11898.html ETIME vs. nget
47 * http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/event_port.c (libc)
48 * http://cvs.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/fs/portfs/port.c#1325 (kernel)
49 */
50
51 #include <sys/types.h>
52 #include <sys/time.h>
53 #include <poll.h>
54 #include <port.h>
55 #include <string.h>
56 #include <errno.h>
57
58 inline_speed
59 void
60 port_associate_and_check (EV_P_ int fd, int ev)
61 {
62 if (0 >
63 port_associate (
64 backend_fd, PORT_SOURCE_FD, fd,
65 (ev & EV_READ ? POLLIN : 0)
66 | (ev & EV_WRITE ? POLLOUT : 0),
67 0
68 )
69 )
70 {
71 if (errno == EBADFD)
72 {
73 assert (("libev: port_associate found invalid fd", errno != EBADFD));
74 fd_kill (EV_A_ fd);
75 }
76 else
77 ev_syserr ("(libev) port_associate");
78 }
79 }
80
81 static void
82 port_modify (EV_P_ int fd, int oev, int nev)
83 {
84 /* we need to reassociate no matter what, as closes are
85 * once more silently being discarded.
86 */
87 if (!nev)
88 {
89 if (oev)
90 port_dissociate (backend_fd, PORT_SOURCE_FD, fd);
91 }
92 else
93 port_associate_and_check (EV_A_ fd, nev);
94 }
95
96 static void
97 port_poll (EV_P_ ev_tstamp timeout)
98 {
99 int res, i;
100 struct timespec ts;
101 uint_t nget = 1;
102
103 /* we initialise this to something we will skip in the loop, as */
104 /* port_getn can return with nget unchanged, but no indication */
105 /* whether it was the original value or has been updated :/ */
106 port_events [0].portev_source = 0;
107
108 EV_RELEASE_CB;
109 EV_TS_SET (ts, timeout);
110 res = port_getn (backend_fd, port_events, port_eventmax, &nget, &ts);
111 EV_ACQUIRE_CB;
112
113 /* port_getn may or may not set nget on error */
114 /* so we rely on port_events [0].portev_source not being updated */
115 if (res == -1 && errno != ETIME && errno != EINTR)
116 ev_syserr ("(libev) port_getn (see https://archive.is/jN6Ck, try LIBEV_FLAGS=3 env variable)");
117
118 for (i = 0; i < nget; ++i)
119 {
120 if (port_events [i].portev_source == PORT_SOURCE_FD)
121 {
122 int fd = port_events [i].portev_object;
123
124 fd_event (
125 EV_A_
126 fd,
127 (port_events [i].portev_events & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
128 | (port_events [i].portev_events & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
129 );
130
131 fd_change (EV_A_ fd, EV__IOFDSET);
132 }
133 }
134
135 if (ecb_expect_false (nget == port_eventmax))
136 {
137 ev_free (port_events);
138 port_eventmax = array_nextsize (sizeof (port_event_t), port_eventmax, port_eventmax + 1);
139 port_events = (port_event_t *)ev_malloc (sizeof (port_event_t) * port_eventmax);
140 }
141 }
142
143 inline_size
144 int
145 port_init (EV_P_ int flags)
146 {
147 /* Initialize the kernel queue */
148 if ((backend_fd = port_create ()) < 0)
149 return 0;
150
151 assert (("libev: PORT_SOURCE_FD must not be zero", PORT_SOURCE_FD));
152
153 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
154
155 /* if my reading of the opensolaris kernel sources are correct, then
156 * opensolaris does something very stupid: it checks if the time has already
157 * elapsed and doesn't round up if that is the case, otherwise it DOES round
158 * up. Since we can't know what the case is, we need to guess by using a
159 * "large enough" timeout. Normally, 1e-9 would be correct.
160 */
161 backend_mintime = EV_TS_CONST (1e-3); /* needed to compensate for port_getn returning early */
162 backend_modify = port_modify;
163 backend_poll = port_poll;
164
165 port_eventmax = 64; /* initial number of events receivable per poll */
166 port_events = (port_event_t *)ev_malloc (sizeof (port_event_t) * port_eventmax);
167
168 return EVBACKEND_PORT;
169 }
170
171 inline_size
172 void
173 port_destroy (EV_P)
174 {
175 ev_free (port_events);
176 }
177
178 inline_size
179 void
180 port_fork (EV_P)
181 {
182 close (backend_fd);
183
184 while ((backend_fd = port_create ()) < 0)
185 ev_syserr ("(libev) port");
186
187 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
188
189 /* re-register interest in fds */
190 fd_rearm_all (EV_A);
191 }
192