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Comparing libev/ev_kqueue.c (file contents):
Revision 1.2 by root, Fri Nov 2 21:17:30 2007 UTC vs.
Revision 1.56 by root, Thu Feb 18 04:48:05 2016 UTC

1
2/* 1/*
2 * libev kqueue backend
3 *
3 * Copyright 2007 Marc Alexander Lehmann <libev@schmorp.de> 4 * Copyright (c) 2007,2008,2009,2010,2011,2012,2013 Marc Alexander Lehmann <libev@schmorp.de>
4 * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
5 * All rights reserved. 5 * All rights reserved.
6 * 6 *
7 * Redistribution and use in source and binary forms, with or without 7 * Redistribution and use in source and binary forms, with or without modifica-
8 * modification, are permitted provided that the following conditions 8 * tion, are permitted provided that the following conditions are met:
9 * are met:
10 * 9 *
11 * 1. Redistributions of source code must retain the above copyright 10 * 1. Redistributions of source code must retain the above copyright notice,
12 * notice, this list of conditions and the following disclaimer. 11 * this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright 13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the 14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution. 15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 * 16 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 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.
29 */ 38 */
30 39
31#include <sys/types.h> 40#include <sys/types.h>
32#include <sys/time.h> 41#include <sys/time.h>
33#include <sys/queue.h>
34#include <sys/event.h> 42#include <sys/event.h>
35#include <string.h> 43#include <string.h>
36#include <errno.h> 44#include <errno.h>
37 45
38static int kq_fd; 46inline_speed
39static struct kevent *kq_changes; 47void
40static int kq_changemax, kq_changecnt; 48kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
41static struct kevent *kq_events; 49{
42static int kq_eventmax; 50 ++kqueue_changecnt;
51 array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
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
43 63
44static void 64static void
45kqueue_change (int fd, int filter, int flags, int fflags) 65kqueue_modify (EV_P_ int fd, int oev, int nev)
46{ 66{
47 struct kevent *ke; 67 if (oev != nev)
68 {
69 if (oev & EV_READ)
70 kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
48 71
49 array_needsize (kq_changes, kq_changemax, ++kq_changecnt, ); 72 if (oev & EV_WRITE)
73 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
74 }
50 75
51 ke = &kq_changes [kq_changecnt - 1]; 76 /* to detect close/reopen reliably, we have to re-add */
52 memset (ke, 0, sizeof (struct kevent)); 77 /* event requests even when oev == nev */
53 ke->ident = fd; 78
54 ke->filter = filter; 79 if (nev & EV_READ)
55 ke->flags = flags; 80 kqueue_change (EV_A_ fd, EVFILT_READ , EV_ADD | EV_ENABLE, NOTE_EOF);
56 ke->fflags = fflags; 81
82 if (nev & EV_WRITE)
83 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD | EV_ENABLE, NOTE_EOF);
57} 84}
58 85
59static void 86static void
60kqueue_modify (int fd, int oev, int nev)
61{
62 if ((oev ^ new) & EV_READ)
63 {
64 if (nev & EV_READ)
65 kqueue_change (fd, EVFILT_READ, EV_ADD, NOTE_EOF);
66 else
67 kqueue_change (fd, EVFILT_READ, EV_DELETE, 0);
68 }
69
70 if ((oev ^ new) & EV_WRITE)
71 {
72 if (nev & EV_WRITE)
73 kqueue_change (fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
74 else
75 kqueue_change (fd, EVFILT_WRITE, EV_DELETE, 0);
76 }
77}
78
79static void
80kqueue_poll (ev_tstamp timeout) 87kqueue_poll (EV_P_ ev_tstamp timeout)
81{ 88{
82 int res, i; 89 int res, i;
83 struct timespec ts; 90 struct timespec ts;
84 91
85 ts.tv_sec = (time_t)timeout; 92 /* need to resize so there is enough space for errors */
86 ts.tv_nsec = (long)(timeout - (ev_tstamp)ts.tv_sec) * 1e9; 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);
87 res = kevent (kq_fd, kq_changes, kq_changecnt, kq_events, kq_eventmax, &ts); 102 res = kevent (backend_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
103 EV_ACQUIRE_CB;
88 kq_changecnt = 0; 104 kqueue_changecnt = 0;
89 105
90 if (res < 0) 106 if (expect_false (res < 0))
107 {
108 if (errno != EINTR)
109 ev_syserr ("(libev) kevent");
110
91 return; 111 return;
112 }
92 113
93 for (i = 0; i < res; ++i) 114 for (i = 0; i < res; ++i)
94 { 115 {
116 int fd = kqueue_events [i].ident;
117
95 if (kq_events [i].flags & EV_ERROR) 118 if (expect_false (kqueue_events [i].flags & EV_ERROR))
96 { 119 {
97 /* 120 int err = kqueue_events [i].data;
98 * Error messages that can happen, when a delete fails. 121
99 * EBADF happens when the file discriptor has been 122 /* we are only interested in errors for fds that we are interested in :) */
100 * closed, 123 if (anfds [fd].events)
101 * ENOENT when the file discriptor was closed and
102 * then reopened.
103 * EINVAL for some reasons not understood; EINVAL
104 * should not be returned ever; but FreeBSD does :-\
105 * An error is also indicated when a callback deletes
106 * an event we are still processing. In that case
107 * the data field is set to ENOENT.
108 */ 124 {
109 if (events [i].data == EBADF) 125 if (err == ENOENT) /* resubmit changes on ENOENT */
110 fd_kill (events [i].ident); 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 fd_kill (EV_A_ fd);
133 }
134 else /* on all other errors, we error out on the fd */
135 fd_kill (EV_A_ fd);
136 }
111 } 137 }
112 else 138 else
113 event ( 139 fd_event (
114 events [i].ident, 140 EV_A_
141 fd,
115 events [i].filter == EVFILT_READ ? EV_READ 142 kqueue_events [i].filter == EVFILT_READ ? EV_READ
116 : events [i].filter == EVFILT_WRITE ? EV_WRITE 143 : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
117 : 0 144 : 0
118 ); 145 );
119 } 146 }
120 147
121 if (expect_false (res == kq_eventmax)) 148 if (expect_false (res == kqueue_eventmax))
122 { 149 {
123 free (kq_events); 150 ev_free (kqueue_events);
124 kq_eventmax = array_roundsize (kq_events, kq_eventmax << 1); 151 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
125 kq_events = malloc (sizeof (struct kevent) * kq_eventmax); 152 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
126 } 153 }
127} 154}
128 155
129static void 156inline_size
130kqueue_init (struct event_base *base) 157int
158kqueue_init (EV_P_ int flags)
131{ 159{
132 struct kevent ch, ev;
133
134 /* Initalize the kernel queue */ 160 /* initialize the kernel queue */
161 kqueue_fd_pid = getpid ();
135 if ((kq_fd = kqueue ()) < 0) 162 if ((backend_fd = kqueue ()) < 0)
136 return; 163 return 0;
137 164
138 /* Check for Mac OS X kqueue bug. */ 165 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
139 ch.ident = -1;
140 ch.filter = EVFILT_READ;
141 ch.flags = EV_ADD;
142 166
143 /* 167 backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
144 * If kqueue works, then kevent will succeed, and it will 168 backend_modify = kqueue_modify;
145 * stick an error in events[0]. If kqueue is broken, then 169 backend_poll = kqueue_poll;
146 * kevent will fail. 170
171 kqueue_eventmax = 64; /* initial number of events receivable per poll */
172 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
173
174 kqueue_changes = 0;
175 kqueue_changemax = 0;
176 kqueue_changecnt = 0;
177
178 return EVBACKEND_KQUEUE;
179}
180
181inline_size
182void
183kqueue_destroy (EV_P)
184{
185 ev_free (kqueue_events);
186 ev_free (kqueue_changes);
187}
188
189inline_size
190void
191kqueue_fork (EV_P)
192{
193 /* some BSD kernels don't just destroy the kqueue itself,
194 * but also close the fd, which isn't documented, and
195 * impossible to support properly.
196 * we remember the pid of the kqueue call and only close
197 * the fd if the pid is still the same.
198 * this leaks fds on sane kernels, but BSD interfaces are
199 * notoriously buggy and rarely get fixed.
147 */ 200 */
148 if (kevent (kq_fd, &ch, 1, &ev, 1, 0) != 1 201 pid_t newpid = getpid ();
149 || ev.ident != -1 202
150 || ev.flags != EV_ERROR) 203 if (newpid == kqueue_fd_pid)
151 {
152 /* detected broken kqueue */
153 close (kq_fd); 204 close (backend_fd);
154 return;
155 }
156 205
157 ev_method = EVMETHOD_KQUEUE; 206 kqueue_fd_pid = newpid;
158 method_fudge = 1e-3; /* needed to compensate for kevent returning early */ 207 while ((backend_fd = kqueue ()) < 0)
159 method_modify = kq_modify; 208 ev_syserr ("(libev) kqueue");
160 method_poll = kq_poll;
161 209
162 kq_eventmax = 64; /* intiial number of events receivable per poll */ 210 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
163 kq_events = malloc (sizeof (struct kevent) * kq_eventmax);
164}
165 211
212 /* re-register interest in fds */
213 fd_rearm_all (EV_A);
214}
215
216/* sys/event.h defines EV_ERROR */
217#undef EV_ERROR
218

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