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
41 // file descriptors used for wakeup during shutdown
42 private final int fd0;
43 private final int fd1;
44
45 // close action, and cleaner if this is subpoller
46 private final Runnable closer;
47 private final Cleanable cleaner;
48
49 KQueuePoller(boolean subPoller, boolean read) throws IOException {
50 int maxEvents = (subPoller) ? 16 : 64;
51
52 int kqfd = -1;
53 long address = 0L;
54 int fd0 = -1;
55 int fd1 = -1;
56 try {
57 kqfd = KQueue.create();
58 address = KQueue.allocatePollArray(maxEvents);
59
60 // register one of the pipe with kqueue to allow for wakeup
61 long fds = IOUtil.makePipe(false);
62 fd0 = (int) (fds >>> 32);
63 fd1 = (int) fds;
64 KQueue.register(kqfd, fd0, EVFILT_READ, EV_ADD);
65 } catch (Throwable e) {
66 if (kqfd >= 0) FileDispatcherImpl.closeIntFD(kqfd);
67 if (address != 0L) KQueue.freePollArray(address);
68 if (fd0 >= 0) FileDispatcherImpl.closeIntFD(fd0);
69 if (fd1 >= 0) FileDispatcherImpl.closeIntFD(fd1);
70 throw e;
71 }
72
73 this.kqfd = kqfd;
74 this.filter = (read) ? EVFILT_READ : EVFILT_WRITE;
75 this.maxEvents = maxEvents;
76 this.address = address;
77 this.fd0 = fd0;
78 this.fd1 = fd1;
79
80 // create action to close kqueue, register cleaner if this is a subpoller
81 this.closer = closer(kqfd, address, fd0, fd1);
82 if (subPoller) {
83 this.cleaner = CleanerFactory.cleaner().register(this, closer);
84 } else {
85 this.cleaner = null;
86 }
87 }
88
89 /**
90 * Returns an action to close the kqueue and release other resources.
91 */
92 private static Runnable closer(int kqfd, long address, int fd0, int fd1) {
93 return () -> {
94 try {
95 FileDispatcherImpl.closeIntFD(kqfd);
96 KQueue.freePollArray(address);
97 FileDispatcherImpl.closeIntFD(fd0);
98 FileDispatcherImpl.closeIntFD(fd1);
99 } catch (IOException _) { }
100 };
101 }
102
103 @Override
104 void close() {
105 if (cleaner != null) {
106 cleaner.clean();
107 } else {
108 closer.run();
109 }
110 }
111
112 @Override
113 int fdVal() {
114 return kqfd;
115 }
116
117 @Override
118 void implRegister(int fdVal) throws IOException {
119 int err = KQueue.register(kqfd, fdVal, filter, (EV_ADD|EV_ONESHOT));
120 if (err != 0)
121 throw new IOException("kevent failed: " + err);
122 }
123
124 @Override
125 void implDeregister(int fdVal, boolean polled) {
126 // event was deleted if already polled
127 if (!polled) {
128 KQueue.register(kqfd, fdVal, filter, EV_DELETE);
129 }
130 }
131
132 @Override
133 void wakeupPoller() throws IOException {
134 IOUtil.write1(fd1, (byte)0);
135 }
136
137 @Override
138 int poll(int timeout) throws IOException {
139 int n = KQueue.poll(kqfd, address, maxEvents, timeout);
140 int polled = 0;
141 int i = 0;
142 while (i < n) {
143 long keventAddress = KQueue.getEvent(address, i);
144 int fdVal = KQueue.getDescriptor(keventAddress);
145 if (fdVal != fd0) {
146 polled(fdVal);
147 polled++;
148 }
149 i++;
150 }
151 return polled;
152 }
153 }