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(Poller.Mode mode, boolean subPoller, boolean read) throws IOException {
50 int maxEvents = (subPoller) ? 16 : 64;
51
52 int kqfd = KQueue.create();
53 long address = 0L;
54 int fd0 = -1;
55 int fd1 = -1;
56 try {
57 address = KQueue.allocatePollArray(maxEvents);
58
59 // register one of the pipe with kqueue to allow for wakeup
60 if (subPoller && (mode == Mode.POLLER_PER_CARRIER)) {
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 }
66 } catch (Throwable e) {
67 FileDispatcherImpl.closeIntFD(kqfd);
68 if (address != 0L) KQueue.freePollArray(address);
69 if (fd0 >= 0) FileDispatcherImpl.closeIntFD(fd0);
70 if (fd1 >= 0) FileDispatcherImpl.closeIntFD(fd1);
71 throw e;
72 }
73
74 this.kqfd = kqfd;
75 this.filter = (read) ? EVFILT_READ : EVFILT_WRITE;
76 this.maxEvents = maxEvents;
77 this.address = address;
78 this.fd0 = fd0;
79 this.fd1 = fd1;
80
81 // create action to close kqueue, register cleaner if this is a subpoller
82 this.closer = closer(kqfd, address, fd0, fd1);
83 if (subPoller) {
84 this.cleaner = CleanerFactory.cleaner().register(this, closer);
85 } else {
86 this.cleaner = null;
87 }
88 }
89
90 /**
91 * Returns an action to close the kqueue and release other resources.
92 */
93 private static Runnable closer(int kqfd, long address, int fd0, int fd1) {
94 return () -> {
95 try {
96 FileDispatcherImpl.closeIntFD(kqfd);
97 KQueue.freePollArray(address);
98 if (fd0 >= 0) FileDispatcherImpl.closeIntFD(fd0);
99 if (fd1 >= 0) FileDispatcherImpl.closeIntFD(fd1);
100 } catch (IOException _) { }
101 };
102 }
103
104 @Override
105 void close() {
106 if (cleaner != null) {
107 cleaner.clean();
108 } else {
109 closer.run();
110 }
111 }
112
113 @Override
114 int fdVal() {
115 return kqfd;
116 }
117
118 @Override
119 void implRegister(int fdVal) throws IOException {
120 int err = KQueue.register(kqfd, fdVal, filter, (EV_ADD|EV_ONESHOT));
121 if (err != 0)
122 throw new IOException("kevent failed: " + err);
123 }
124
125 @Override
126 void implDeregister(int fdVal, boolean polled) {
127 // event was deleted if already polled
128 if (!polled) {
129 KQueue.register(kqfd, fdVal, filter, EV_DELETE);
130 }
131 }
132
133 @Override
134 void wakeupPoller() throws IOException {
135 if (fd1 < 0) {
136 throw new UnsupportedOperationException();
137 }
138 IOUtil.write1(fd1, (byte)0);
139 }
140
141 @Override
142 int poll(int timeout) throws IOException {
143 int n = KQueue.poll(kqfd, address, maxEvents, timeout);
144 int polled = 0;
145 int i = 0;
146 while (i < n) {
147 long keventAddress = KQueue.getEvent(address, i);
148 int fdVal = KQueue.getDescriptor(keventAddress);
149 if (fdVal != fd0) {
150 polled(fdVal);
151 polled++;
152 }
153 i++;
154 }
155 return polled;
156 }
157 }