1 /*
2 * Copyright (c) 2001, 2016, 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
26 package sun.nio.ch;
27
28 import java.io.IOException;
29 import java.nio.channels.*;
30 import java.nio.channels.spi.*;
31 import java.util.*;
32
33
34 /**
35 * An abstract selector impl.
36 */
37
38 abstract class AbstractPollSelectorImpl
39 extends SelectorImpl
40 {
41
42 // The poll fd array
43 PollArrayWrapper pollWrapper;
44
45 // Initial capacity of the pollfd array
46 protected final int INIT_CAP = 10;
47
48 // The list of SelectableChannels serviced by this Selector
49 protected SelectionKeyImpl[] channelArray;
50
51 // In some impls the first entry of channelArray is bogus
52 protected int channelOffset = 0;
53
54 // The number of valid channels in this Selector's poll array
55 protected int totalChannels;
56
57 // True if this Selector has been closed
58 private boolean closed = false;
59
60 // Lock for close and cleanup
61 private Object closeLock = new Object();
62
63 AbstractPollSelectorImpl(SelectorProvider sp, int channels, int offset) {
64 super(sp);
65 this.totalChannels = channels;
66 this.channelOffset = offset;
67 }
68
69 public void putEventOps(SelectionKeyImpl sk, int ops) {
70 synchronized (closeLock) {
71 if (closed)
72 throw new ClosedSelectorException();
73 pollWrapper.putEventOps(sk.getIndex(), ops);
74 }
75 }
76
77 public Selector wakeup() {
78 pollWrapper.interrupt();
79 return this;
80 }
81
82 protected abstract int doSelect(long timeout) throws IOException;
83
84 protected void implClose() throws IOException {
85 synchronized (closeLock) {
86 if (closed)
87 return;
88 closed = true;
89 // Deregister channels
90 for(int i=channelOffset; i<totalChannels; i++) {
91 SelectionKeyImpl ski = channelArray[i];
92 assert(ski.getIndex() != -1);
93 ski.setIndex(-1);
94 deregister(ski);
95 SelectableChannel selch = channelArray[i].channel();
96 if (!selch.isOpen() && !selch.isRegistered())
97 ((SelChImpl)selch).kill();
98 }
99 implCloseInterrupt();
100 pollWrapper.free();
101 pollWrapper = null;
102 selectedKeys = null;
103 channelArray = null;
104 totalChannels = 0;
105 }
106 }
107
108 protected abstract void implCloseInterrupt() throws IOException;
109
110 /**
111 * Copy the information in the pollfd structs into the opss
112 * of the corresponding Channels. Add the ready keys to the
113 * ready queue.
114 */
115 protected int updateSelectedKeys() {
116 int numKeysUpdated = 0;
117 // Skip zeroth entry; it is for interrupts only
118 for (int i=channelOffset; i<totalChannels; i++) {
119 int rOps = pollWrapper.getReventOps(i);
120 if (rOps != 0) {
121 SelectionKeyImpl sk = channelArray[i];
122 pollWrapper.putReventOps(i, 0);
123 if (selectedKeys.contains(sk)) {
124 if (sk.channel.translateAndSetReadyOps(rOps, sk)) {
125 numKeysUpdated++;
126 }
127 } else {
128 sk.channel.translateAndSetReadyOps(rOps, sk);
129 if ((sk.nioReadyOps() & sk.nioInterestOps()) != 0) {
130 selectedKeys.add(sk);
131 numKeysUpdated++;
132 }
133 }
134 }
135 }
136 return numKeysUpdated;
137 }
138
139 protected void implRegister(SelectionKeyImpl ski) {
140 synchronized (closeLock) {
141 if (closed)
142 throw new ClosedSelectorException();
143
144 // Check to see if the array is large enough
145 if (channelArray.length == totalChannels) {
146 // Make a larger array
147 int newSize = pollWrapper.totalChannels * 2;
148 SelectionKeyImpl temp[] = new SelectionKeyImpl[newSize];
149 // Copy over
150 for (int i=channelOffset; i<totalChannels; i++)
151 temp[i] = channelArray[i];
152 channelArray = temp;
153 // Grow the NativeObject poll array
154 pollWrapper.grow(newSize);
155 }
156 channelArray[totalChannels] = ski;
157 ski.setIndex(totalChannels);
158 pollWrapper.addEntry(ski.channel);
159 totalChannels++;
160 keys.add(ski);
161 }
162 }
163
164 protected void implDereg(SelectionKeyImpl ski) throws IOException {
165 // Algorithm: Copy the sc from the end of the list and put it into
166 // the location of the sc to be removed (since order doesn't
167 // matter). Decrement the sc count. Update the index of the sc
168 // that is moved.
169 int i = ski.getIndex();
170 assert (i >= 0);
171 if (i != totalChannels - 1) {
172 // Copy end one over it
173 SelectionKeyImpl endChannel = channelArray[totalChannels-1];
174 channelArray[i] = endChannel;
175 endChannel.setIndex(i);
176 pollWrapper.release(i);
177 PollArrayWrapper.replaceEntry(pollWrapper, totalChannels - 1,
178 pollWrapper, i);
179 } else {
180 pollWrapper.release(i);
181 }
182 // Destroy the last one
183 channelArray[totalChannels-1] = null;
184 totalChannels--;
185 pollWrapper.totalChannels--;
186 ski.setIndex(-1);
187 // Remove the key from keys and selectedKeys
188 keys.remove(ski);
189 selectedKeys.remove(ski);
190 deregister((AbstractSelectionKey)ski);
191 SelectableChannel selch = ski.channel();
192 if (!selch.isOpen() && !selch.isRegistered())
193 ((SelChImpl)selch).kill();
194 }
195 }