1 /* 2 * Copyright (c) 2001, 2013, 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 32 33 /** 34 * An abstract selector impl. 35 */ 36 37 abstract class AbstractPollSelectorImpl 38 extends SelectorImpl 39 { 40 41 // The poll fd array 42 PollArrayWrapper pollWrapper; 43 44 // Initial capacity of the pollfd array 45 protected final int INIT_CAP = 10; 46 47 // The list of SelectableChannels serviced by this Selector 48 protected SelectionKeyImpl[] channelArray; 49 50 // In some impls the first entry of channelArray is bogus 51 protected int channelOffset = 0; 52 53 // The number of valid channels in this Selector's poll array 54 protected int totalChannels; 55 56 // True if this Selector has been closed 57 private boolean closed = false; 58 59 // Lock for close and cleanup 60 private Object closeLock = new Object(); 61 62 AbstractPollSelectorImpl(SelectorProvider sp, int channels, int offset) { 63 super(sp); 64 this.totalChannels = channels; 65 this.channelOffset = offset; 66 } 67 68 public void putEventOps(SelectionKeyImpl sk, int ops) { 69 synchronized (closeLock) { 70 if (closed) 71 throw new ClosedSelectorException(); 72 pollWrapper.putEventOps(sk.getIndex(), ops); 73 } 74 } 75 76 public Selector wakeup() { 77 pollWrapper.interrupt(); 78 return this; 79 } 80 81 protected abstract int doSelect(long timeout) throws IOException; 82 83 protected void implClose() throws IOException { 84 synchronized (closeLock) { 85 if (closed) 86 return; 87 closed = true; 88 // Deregister channels 89 for(int i=channelOffset; i<totalChannels; i++) { 90 SelectionKeyImpl ski = channelArray[i]; 91 assert(ski.getIndex() != -1); 92 ski.setIndex(-1); 93 deregister(ski); 94 SelectableChannel selch = channelArray[i].channel(); 95 if (!selch.isOpen() && !selch.isRegistered()) 96 ((SelChImpl)selch).kill(); 97 } 98 implCloseInterrupt(); 99 pollWrapper.free(); 100 pollWrapper = null; 101 selectedKeys = null; 102 channelArray = null; 103 totalChannels = 0; 104 } 105 } 106 107 protected abstract void implCloseInterrupt() throws IOException; 108 109 /** 110 * Copy the information in the pollfd structs into the opss 111 * of the corresponding Channels. Add the ready keys to the 112 * ready queue. 113 */ 114 protected int updateSelectedKeys() { 115 int numKeysUpdated = 0; 116 // Skip zeroth entry; it is for interrupts only 117 for (int i=channelOffset; i<totalChannels; i++) { 118 int rOps = pollWrapper.getReventOps(i); 119 if (rOps != 0) { 120 SelectionKeyImpl sk = channelArray[i]; 121 pollWrapper.putReventOps(i, 0); 122 if (selectedKeys.contains(sk)) { 123 if (sk.channel.translateAndSetReadyOps(rOps, sk)) { 124 numKeysUpdated++; 125 } 126 } else { 127 sk.channel.translateAndSetReadyOps(rOps, sk); 128 if ((sk.nioReadyOps() & sk.nioInterestOps()) != 0) { 129 selectedKeys.add(sk); 130 numKeysUpdated++; 131 } 132 } 133 } 134 } 135 return numKeysUpdated; 136 } 137 138 protected void implRegister(SelectionKeyImpl ski) { 139 synchronized (closeLock) { 140 if (closed) 141 throw new ClosedSelectorException(); 142 143 // Check to see if the array is large enough 144 if (channelArray.length == totalChannels) { 145 // Make a larger array 146 int newSize = pollWrapper.totalChannels * 2; 147 SelectionKeyImpl temp[] = new SelectionKeyImpl[newSize]; 148 // Copy over 149 for (int i=channelOffset; i<totalChannels; i++) 150 temp[i] = channelArray[i]; 151 channelArray = temp; 152 // Grow the NativeObject poll array 153 pollWrapper.grow(newSize); 154 } 155 channelArray[totalChannels] = ski; 156 ski.setIndex(totalChannels); 157 pollWrapper.addEntry(ski.channel); 158 totalChannels++; 159 keys.add(ski); 160 } 161 } 162 163 protected void implDereg(SelectionKeyImpl ski) throws IOException { 164 // Algorithm: Copy the sc from the end of the list and put it into 165 // the location of the sc to be removed (since order doesn't 166 // matter). Decrement the sc count. Update the index of the sc 167 // that is moved. 168 int i = ski.getIndex(); 169 assert (i >= 0); 170 if (i != totalChannels - 1) { 171 // Copy end one over it 172 SelectionKeyImpl endChannel = channelArray[totalChannels-1]; 173 channelArray[i] = endChannel; 174 endChannel.setIndex(i); 175 pollWrapper.release(i); 176 PollArrayWrapper.replaceEntry(pollWrapper, totalChannels - 1, 177 pollWrapper, i); 178 } else { 179 pollWrapper.release(i); 180 } 181 // Destroy the last one 182 channelArray[totalChannels-1] = null; 183 totalChannels--; 184 pollWrapper.totalChannels--; 185 ski.setIndex(-1); 186 // Remove the key from keys and selectedKeys 187 keys.remove(ski); 188 selectedKeys.remove(ski); 189 deregister((AbstractSelectionKey)ski); 190 SelectableChannel selch = ski.channel(); 191 if (!selch.isOpen() && !selch.isRegistered()) 192 ((SelChImpl)selch).kill(); 193 } 194 } 195
