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/cvs/libev/ev_kqueue.c
Revision: 1.59
Committed: Wed Jun 26 00:01:46 2019 UTC (5 years ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: EV-rel-4_27, rel-4_27
Changes since 1.58: +8 -2 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 /*
2 * libev kqueue backend
3 *
4 * Copyright (c) 2007,2008,2009,2010,2011,2012,2013,2016,2019 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 #include <sys/types.h>
41 #include <sys/time.h>
42 #include <sys/event.h>
43 #include <string.h>
44 #include <errno.h>
45
46 inline_speed
47 void
48 kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
49 {
50 ++kqueue_changecnt;
51 array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, array_needsize_noinit);
52
53 EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
54 }
55
56 /* OS X at least needs this */
57 #ifndef EV_ENABLE
58 # define EV_ENABLE 0
59 #endif
60 #ifndef NOTE_EOF
61 # define NOTE_EOF 0
62 #endif
63
64 static void
65 kqueue_modify (EV_P_ int fd, int oev, int nev)
66 {
67 if (oev != nev)
68 {
69 if (oev & EV_READ)
70 kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
71
72 if (oev & EV_WRITE)
73 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
74 }
75
76 /* to detect close/reopen reliably, we have to re-add */
77 /* event requests even when oev == nev */
78
79 if (nev & EV_READ)
80 kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD | EV_ENABLE, NOTE_EOF);
81
82 if (nev & EV_WRITE)
83 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, NOTE_EOF);
84 }
85
86 static void
87 kqueue_poll (EV_P_ ev_tstamp timeout)
88 {
89 int res, i;
90 struct timespec ts;
91
92 /* need to resize so there is enough space for errors */
93 if (kqueue_changecnt > kqueue_eventmax)
94 {
95 ev_free (kqueue_events);
96 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_changecnt);
97 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
98 }
99
100 EV_RELEASE_CB;
101 EV_TS_SET (ts, timeout);
102 res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
103 EV_ACQUIRE_CB;
104 kqueue_changecnt = 0;
105
106 if (expect_false (res < 0))
107 {
108 if (errno != EINTR)
109 ev_syserr ("(libev) kqueue kevent");
110
111 return;
112 }
113
114 for (i = 0; i < res; ++i)
115 {
116 int fd = kqueue_events [i].ident;
117
118 if (expect_false (kqueue_events [i].flags & EV_ERROR))
119 {
120 int err = kqueue_events [i].data;
121
122 /* we are only interested in errors for fds that we are interested in :) */
123 if (anfds [fd].events)
124 {
125 if (err == ENOENT) /* resubmit changes on ENOENT */
126 kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
127 else if (err == EBADF) /* on EBADF, we re-check the fd */
128 {
129 if (fd_valid (fd))
130 kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
131 else
132 {
133 assert (("libev: kqueue found invalid fd", 0));
134 fd_kill (EV_A_ fd);
135 }
136 }
137 else /* on all other errors, we error out on the fd */
138 {
139 assert (("libev: kqueue found invalid fd", 0));
140 fd_kill (EV_A_ fd);
141 }
142 }
143 }
144 else
145 fd_event (
146 EV_A_
147 fd,
148 kqueue_events [i].filter == EVFILT_READ ? EV_READ
149 : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
150 : 0
151 );
152 }
153
154 if (expect_false (res == kqueue_eventmax))
155 {
156 ev_free (kqueue_events);
157 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
158 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
159 }
160 }
161
162 inline_size
163 int
164 kqueue_init (EV_P_ int flags)
165 {
166 /* initialize the kernel queue */
167 kqueue_fd_pid = getpid ();
168 if ((backend_fd = kqueue ()) < 0)
169 return 0;
170
171 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
172
173 backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
174 backend_modify = kqueue_modify;
175 backend_poll = kqueue_poll;
176
177 kqueue_eventmax = 64; /* initial number of events receivable per poll */
178 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
179
180 kqueue_changes = 0;
181 kqueue_changemax = 0;
182 kqueue_changecnt = 0;
183
184 return EVBACKEND_KQUEUE;
185 }
186
187 inline_size
188 void
189 kqueue_destroy (EV_P)
190 {
191 ev_free (kqueue_events);
192 ev_free (kqueue_changes);
193 }
194
195 inline_size
196 void
197 kqueue_fork (EV_P)
198 {
199 /* some BSD kernels don't just destroy the kqueue itself,
200 * but also close the fd, which isn't documented, and
201 * impossible to support properly.
202 * we remember the pid of the kqueue call and only close
203 * the fd if the pid is still the same.
204 * this leaks fds on sane kernels, but BSD interfaces are
205 * notoriously buggy and rarely get fixed.
206 */
207 pid_t newpid = getpid ();
208
209 if (newpid == kqueue_fd_pid)
210 close (backend_fd);
211
212 kqueue_fd_pid = newpid;
213 while ((backend_fd = kqueue ()) < 0)
214 ev_syserr ("(libev) kqueue");
215
216 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
217
218 /* re-register interest in fds */
219 fd_rearm_all (EV_A);
220 }
221
222 /* sys/event.h defines EV_ERROR */
223 #undef EV_ERROR
224