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Comparing libev/ev_kqueue.c (file contents):
Revision 1.4 by root, Sat Nov 3 16:23:11 2007 UTC vs.
Revision 1.57 by root, Thu Jun 20 22:44:59 2019 UTC

1/* 1/*
2 * Copyright 2007 Marc Alexander Lehmann <libev@schmorp.de> 2 * libev kqueue backend
3 * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu> 3 *
4 * Copyright (c) 2007,2008,2009,2010,2011,2012,2013,2016,2019 Marc Alexander Lehmann <libev@schmorp.de>
4 * All rights reserved. 5 * All rights reserved.
5 * 6 *
6 * Redistribution and use in source and binary forms, with or without 7 * Redistribution and use in source and binary forms, with or without modifica-
7 * modification, are permitted provided that the following conditions 8 * tion, are permitted provided that the following conditions are met:
8 * are met:
9 * 9 *
10 * 1. Redistributions of source code must retain the above copyright 10 * 1. Redistributions of source code must retain the above copyright notice,
11 * notice, this list of conditions and the following disclaimer. 11 * this list of conditions and the following disclaimer.
12 *
12 * 2. Redistributions in binary form must reproduce the above copyright 13 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the 14 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution. 15 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 * 16 *
18 * 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
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
21 * 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-
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * 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;
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
26 * (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
27 * 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.
28 */ 38 */
29 39
30#include <sys/types.h> 40#include <sys/types.h>
31#include <sys/time.h> 41#include <sys/time.h>
32#include <sys/queue.h>
33#include <sys/event.h> 42#include <sys/event.h>
34#include <string.h> 43#include <string.h>
35#include <errno.h> 44#include <errno.h>
36 45
37static int kq_fd; 46inline_speed
38static struct kevent *kq_changes; 47void
39static int kq_changemax, kq_changecnt;
40static struct kevent *kq_events;
41static int kq_eventmax;
42
43static void
44kqueue_change (int fd, int filter, int flags, int fflags) 48kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)
45{ 49{
46 struct kevent *ke; 50 ++kqueue_changecnt;
51 array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, array_needsize_noinit);
47 52
48 array_needsize (kq_changes, kq_changemax, ++kq_changecnt, ); 53 EV_SET (&kqueue_changes [kqueue_changecnt - 1], fd, filter, flags, fflags, 0, 0);
49
50 ke = &kq_changes [kq_changecnt - 1];
51 memset (ke, 0, sizeof (struct kevent));
52 ke->ident = fd;
53 ke->filter = filter;
54 ke->flags = flags;
55 ke->fflags = fflags;
56} 54}
57 55
56/* OS X at least needs this */
57#ifndef EV_ENABLE
58# define EV_ENABLE 0
59#endif
58#ifndef NOTE_EOF 60#ifndef NOTE_EOF
59# define NOTE_EOF 0 61# define NOTE_EOF 0
60#endif 62#endif
61 63
62static void 64static void
63kqueue_modify (int fd, int oev, int nev) 65kqueue_modify (EV_P_ int fd, int oev, int nev)
64{ 66{
65 if ((oev ^ nev) & EV_READ) 67 if (oev != nev)
66 { 68 {
67 if (nev & EV_READ) 69 if (oev & EV_READ)
68 kqueue_change (fd, EVFILT_READ, EV_ADD, NOTE_EOF);
69 else
70 kqueue_change (fd, EVFILT_READ, EV_DELETE, 0); 70 kqueue_change (EV_A_ fd, EVFILT_READ , EV_DELETE, 0);
71 }
72 71
73 if ((oev ^ nev) & EV_WRITE)
74 {
75 if (nev & EV_WRITE) 72 if (oev & EV_WRITE)
76 kqueue_change (fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
77 else
78 kqueue_change (fd, EVFILT_WRITE, EV_DELETE, 0); 73 kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
79 } 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);
80} 84}
81 85
82static void 86static void
83kqueue_poll (ev_tstamp timeout) 87kqueue_poll (EV_P_ ev_tstamp timeout)
84{ 88{
85 int res, i; 89 int res, i;
86 struct timespec ts; 90 struct timespec ts;
87 91
88 ts.tv_sec = (time_t)timeout; 92 /* need to resize so there is enough space for errors */
89 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);
90 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;
91 kq_changecnt = 0; 104 kqueue_changecnt = 0;
92 105
93 if (res < 0) 106 if (expect_false (res < 0))
107 {
108 if (errno != EINTR)
109 ev_syserr ("(libev) kevent");
110
94 return; 111 return;
112 }
95 113
96 for (i = 0; i < res; ++i) 114 for (i = 0; i < res; ++i)
97 { 115 {
116 int fd = kqueue_events [i].ident;
117
98 if (kq_events [i].flags & EV_ERROR) 118 if (expect_false (kqueue_events [i].flags & EV_ERROR))
99 { 119 {
100 /* 120 int err = kqueue_events [i].data;
101 * Error messages that can happen, when a delete fails. 121
102 * EBADF happens when the file discriptor has been 122 /* we are only interested in errors for fds that we are interested in :) */
103 * closed, 123 if (anfds [fd].events)
104 * ENOENT when the file discriptor was closed and
105 * then reopened.
106 * EINVAL for some reasons not understood; EINVAL
107 * should not be returned ever; but FreeBSD does :-\
108 * An error is also indicated when a callback deletes
109 * an event we are still processing. In that case
110 * the data field is set to ENOENT.
111 */ 124 {
112 if (kq_events [i].data == EBADF) 125 if (err == ENOENT) /* resubmit changes on ENOENT */
113 fd_kill (kq_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 }
114 } 137 }
115 else 138 else
116 fd_event ( 139 fd_event (
117 kq_events [i].ident, 140 EV_A_
141 fd,
118 kq_events [i].filter == EVFILT_READ ? EV_READ 142 kqueue_events [i].filter == EVFILT_READ ? EV_READ
119 : kq_events [i].filter == EVFILT_WRITE ? EV_WRITE 143 : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE
120 : 0 144 : 0
121 ); 145 );
122 } 146 }
123 147
124 if (expect_false (res == kq_eventmax)) 148 if (expect_false (res == kqueue_eventmax))
125 { 149 {
126 free (kq_events); 150 ev_free (kqueue_events);
127 kq_eventmax = array_roundsize (kq_events, kq_eventmax << 1); 151 kqueue_eventmax = array_nextsize (sizeof (struct kevent), kqueue_eventmax, kqueue_eventmax + 1);
128 kq_events = malloc (sizeof (struct kevent) * kq_eventmax); 152 kqueue_events = (struct kevent *)ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
129 } 153 }
130} 154}
131 155
132static void 156inline_size
157int
133kqueue_init (int flags) 158kqueue_init (EV_P_ int flags)
134{ 159{
135 struct kevent ch, ev;
136
137 /* Initalize the kernel queue */ 160 /* initialize the kernel queue */
161 kqueue_fd_pid = getpid ();
138 if ((kq_fd = kqueue ()) < 0) 162 if ((backend_fd = kqueue ()) < 0)
139 return; 163 return 0;
140 164
141 /* Check for Mac OS X kqueue bug. */ 165 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */
142 ch.ident = -1;
143 ch.filter = EVFILT_READ;
144 ch.flags = EV_ADD;
145 166
146 /* 167 backend_mintime = 1e-9; /* apparently, they did the right thing in freebsd */
147 * If kqueue works, then kevent will succeed, and it will 168 backend_modify = kqueue_modify;
148 * stick an error in ev. If kqueue is broken, then 169 backend_poll = kqueue_poll;
149 * 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.
150 */ 200 */
151 if (kevent (kq_fd, &ch, 1, &ev, 1, 0) != 1 201 pid_t newpid = getpid ();
152 || ev.ident != -1 202
153 || ev.flags != EV_ERROR) 203 if (newpid == kqueue_fd_pid)
154 {
155 /* detected broken kqueue */
156 close (kq_fd); 204 close (backend_fd);
157 return;
158 }
159 205
160 ev_method = EVMETHOD_KQUEUE; 206 kqueue_fd_pid = newpid;
161 method_fudge = 1e-3; /* needed to compensate for kevent returning early */ 207 while ((backend_fd = kqueue ()) < 0)
162 method_modify = kq_modify; 208 ev_syserr ("(libev) kqueue");
163 method_poll = kq_poll;
164 209
165 kq_eventmax = 64; /* intiial number of events receivable per poll */ 210 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
166 kq_events = malloc (sizeof (struct kevent) * kq_eventmax);
167}
168 211
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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