1 /*
2 * Copyright (c) 2017, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package sun.nio.ch;
26
27 import java.io.IOException;
28 import java.lang.ref.Cleaner.Cleanable;
29 import jdk.internal.ref.CleanerFactory;
30 import static sun.nio.ch.KQueue.*;
31
32 /**
33 * Poller implementation based on the kqueue facility.
34 */
35 class KQueuePoller extends Poller {
36 private final int kqfd;
37 private final int filter;
38 private final int maxEvents;
39 private final long address;
40 private final Cleanable cleaner;
41
42 // file descriptors used for wakeup during shutdown
43 private final int fd0;
44 private final int fd1;
45
46 KQueuePoller(boolean subPoller, boolean read) throws IOException {
47 int maxEvents = (subPoller) ? 16 : 64;
48
49 int kqfd = -1;
50 long address = 0L;
51 int fd0 = -1;
52 int fd1 = -1;
53 try {
54 kqfd = KQueue.create();
55 address = KQueue.allocatePollArray(maxEvents);
56
57 // register one of the pipe with kqueue to allow for wakeup
58 long fds = IOUtil.makePipe(false);
59 fd0 = (int) (fds >>> 32);
60 fd1 = (int) fds;
61 KQueue.register(kqfd, fd0, EVFILT_READ, EV_ADD);
62 } catch (Throwable e) {
63 if (kqfd >= 0) FileDispatcherImpl.closeIntFD(kqfd);
64 if (address != 0L) KQueue.freePollArray(address);
65 if (fd0 >= 0) FileDispatcherImpl.closeIntFD(fd0);
66 if (fd1 >= 0) FileDispatcherImpl.closeIntFD(fd1);
67 throw e;
68 }
69
70 this.kqfd = kqfd;
71 this.filter = (read) ? EVFILT_READ : EVFILT_WRITE;
72 this.maxEvents = maxEvents;
73 this.address = address;
74 this.fd0 = fd0;
75 this.fd1 = fd1;
76
77 this.cleaner = CleanerFactory.cleaner()
78 .register(this, releaser(kqfd, address, fd0, fd1));
79 }
80
81 /**
82 * Releases the kqueue instance and other resources.
83 */
84 private static Runnable releaser(int kqfd, long address, int fd0, int fd1) {
85 return () -> {
86 try {
87 FileDispatcherImpl.closeIntFD(kqfd);
88 KQueue.freePollArray(address);
89 FileDispatcherImpl.closeIntFD(fd0);
90 FileDispatcherImpl.closeIntFD(fd1);
91 } catch (IOException _) { }
92 };
93 }
94
95 @Override
96 void close() {
97 cleaner.clean();
98 }
99
100 @Override
101 int fdVal() {
102 return kqfd;
103 }
104
105 @Override
106 void implRegister(int fdVal) throws IOException {
107 int err = KQueue.register(kqfd, fdVal, filter, (EV_ADD|EV_ONESHOT));
108 if (err != 0)
109 throw new IOException("kevent failed: " + err);
110 }
111
112 @Override
113 void implDeregister(int fdVal, boolean polled) {
114 // event was deleted if already polled
115 if (!polled) {
116 KQueue.register(kqfd, fdVal, filter, EV_DELETE);
117 }
118 }
119
120 @Override
121 void wakeupPoller() throws IOException {
122 IOUtil.write1(fd1, (byte)0);
123 }
124
125 @Override
126 int poll(int timeout) throws IOException {
127 int n = KQueue.poll(kqfd, address, maxEvents, timeout);
128 int polled = 0;
129 int i = 0;
130 while (i < n) {
131 long keventAddress = KQueue.getEvent(address, i);
132 int fdVal = KQueue.getDescriptor(keventAddress);
133 if (fdVal != fd0) {
134 polled(fdVal);
135 polled++;
136 }
137 i++;
138 }
139 return polled;
140 }
141 }