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/cvs/libev/ev_kqueue.c
Revision: 1.54
Committed: Mon Apr 2 18:39:54 2012 UTC (12 years, 3 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rxvt-unicode-rel-9_16, rel-4_15
Changes since 1.53: +15 -2 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 /*
2 * libev kqueue backend
3 *
4 * Copyright (c) 2007,2008,2009,2010,2011,2012 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 <sys/types.h>
41 #include <sys/time.h>
42 #include <sys/event.h>
43 #include <string.h>
44 #include <errno.h>
45
46 void inline_speed
47 kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
48 {
49 ++kqueue_changecnt;
50 array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
51
52 EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
53 }
54
55 /* OS X at least needs this */
56 #ifndef EV_ENABLE
57 # define EV_ENABLE 0
58 #endif
59 #ifndef NOTE_EOF
60 # define NOTE_EOF 0
61 #endif
62
63 static void
64 kqueue_modify (EV_P_ int fd, int oev, int nev)
65 {
66 if (oev != nev)
67 {
68 if (oev & EV_READ)
69 kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
70
71 if (oev & EV_WRITE)
72 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
73 }
74
75 /* to detect close/reopen reliably, we have to re-add */
76 /* event requests even when oev == nev */
77
78 if (nev & EV_READ)
79 kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD | EV_ENABLE, NOTE_EOF);
80
81 if (nev & EV_WRITE)
82 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, NOTE_EOF);
83 }
84
85 static void
86 kqueue_poll (EV_P_ ev_tstamp timeout)
87 {
88 int res, i;
89 struct timespec ts;
90
91 /* need to resize so there is enough space for errors */
92 if (kqueue_changecnt > kqueue_eventmax)
93 {
94 ev_free (kqueue_events);
95 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_changecnt);
96 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
97 }
98
99 EV_RELEASE_CB;
100 EV_TS_SET (ts, timeout);
101 res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
102 EV_ACQUIRE_CB;
103 kqueue_changecnt = 0;
104
105 if (expect_false (res < 0))
106 {
107 if (errno != EINTR)
108 ev_syserr ("(libev) kevent");
109
110 return;
111 }
112
113 for (i = 0; i < res; ++i)
114 {
115 int fd = kqueue_events [i].ident;
116
117 if (expect_false (kqueue_events [i].flags & EV_ERROR))
118 {
119 int err = kqueue_events [i].data;
120
121 /* we are only interested in errors for fds that we are interested in :) */
122 if (anfds [fd].events)
123 {
124 if (err == ENOENT) /* resubmit changes on ENOENT */
125 kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
126 else if (err == EBADF) /* on EBADF, we re-check the fd */
127 {
128 if (fd_valid (fd))
129 kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
130 else
131 fd_kill (EV_A_ fd);
132 }
133 else /* on all other errors, we error out on the fd */
134 fd_kill (EV_A_ fd);
135 }
136 }
137 else
138 fd_event (
139 EV_A_
140 fd,
141 kqueue_events [i].filter == EVFILT_READ ? EV_READ
142 : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
143 : 0
144 );
145 }
146
147 if (expect_false (res == kqueue_eventmax))
148 {
149 ev_free (kqueue_events);
150 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
151 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
152 }
153 }
154
155 int inline_size
156 kqueue_init (EV_P_ int flags)
157 {
158 /* initialize the kernel queue */
159 kqueue_fd_pid = getpid ();
160 if ((backend_fd = kqueue ()) < 0)
161 return 0;
162
163 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
164
165 backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
166 backend_modify = kqueue_modify;
167 backend_poll = kqueue_poll;
168
169 kqueue_eventmax = 64; /* initial number of events receivable per poll */
170 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
171
172 kqueue_changes = 0;
173 kqueue_changemax = 0;
174 kqueue_changecnt = 0;
175
176 return EVBACKEND_KQUEUE;
177 }
178
179 void inline_size
180 kqueue_destroy (EV_P)
181 {
182 ev_free (kqueue_events);
183 ev_free (kqueue_changes);
184 }
185
186 void inline_size
187 kqueue_fork (EV_P)
188 {
189 /* some BSD kernels don't just destroy the kqueue itself,
190 * but also close the fd, which isn't documented, and
191 * impossible to support properly.
192 * we remember the pid of the kqueue call and only close
193 * the fd if the pid is still the same.
194 * this leaks fds on sane kernels, but BSD interfaces are
195 * notoriously buggy and rarely get fixed.
196 */
197 pid_t newpid = getpid ();
198
199 if (newpid == kqueue_fd_pid)
200 close (backend_fd);
201
202 kqueue_fd_pid = newpid;
203 while ((backend_fd = kqueue ()) < 0)
204 ev_syserr ("(libev) kqueue");
205
206 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
207
208 /* re-register interest in fds */
209 fd_rearm_all (EV_A);
210 }
211
212 /* sys/event.h defines EV_ERROR */
213 #undef EV_ERROR
214