1 /*
   2  * Copyright (c) 2000, 2018, 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.nio.channels.CancelledKeyException;
  29 import java.nio.channels.SelectableChannel;
  30 import java.nio.channels.SelectionKey;
  31 import java.nio.channels.Selector;
  32 import java.nio.channels.spi.AbstractSelectionKey;
  33 
  34 
  35 /**
  36  * An implementation of SelectionKey.
  37  */
  38 
  39 public final class SelectionKeyImpl
  40     extends AbstractSelectionKey
  41 {
  42 
  43     final SelChImpl channel;                            // package-private
  44     public final SelectorImpl selector;
  45 
  46     // Index for a pollfd array in Selector that this key is registered with
  47     private int index;
  48 
  49     private volatile int interestOps;
  50     private volatile int readyOps;
  51 
  52     SelectionKeyImpl(SelChImpl ch, SelectorImpl sel) {
  53         channel = ch;
  54         selector = sel;
  55     }
  56 
  57     @Override
  58     public SelectableChannel channel() {
  59         return (SelectableChannel)channel;
  60     }
  61 
  62     @Override
  63     public Selector selector() {
  64         return (Selector)selector;
  65     }
  66 
  67     int getIndex() {                                    // package-private
  68         return index;
  69     }
  70 
  71     void setIndex(int i) {                              // package-private
  72         index = i;
  73     }
  74 
  75     private void ensureValid() {
  76         if (!isValid())
  77             throw new CancelledKeyException();
  78     }
  79 
  80     @Override
  81     public int interestOps() {
  82         ensureValid();
  83         return interestOps;
  84     }
  85 
  86     @Override
  87     public SelectionKey interestOps(int ops) {
  88         ensureValid();
  89         return nioInterestOps(ops);
  90     }
  91 
  92     @Override
  93     public int readyOps() {
  94         ensureValid();
  95         return readyOps;
  96     }
  97 
  98     // The nio versions of these operations do not care if a key
  99     // has been invalidated. They are for internal use by nio code.
 100 
 101     public void nioReadyOps(int ops) {
 102         readyOps = ops;
 103     }
 104 
 105     public int nioReadyOps() {
 106         return readyOps;
 107     }
 108 
 109     public SelectionKey nioInterestOps(int ops) {
 110         if ((ops & ~channel().validOps()) != 0)
 111             throw new IllegalArgumentException();
 112         channel.translateAndSetInterestOps(ops, this);
 113         interestOps = ops;
 114         return this;
 115     }
 116 
 117     public int nioInterestOps() {
 118         return interestOps;
 119     }
 120 
 121     @Override
 122     public String toString() {
 123         StringBuilder sb = new StringBuilder();
 124         sb.append("channel=")
 125           .append(channel)
 126           .append(", selector=")
 127           .append(selector);
 128         if (isValid()) {
 129             sb.append(", interestOps=")
 130               .append(interestOps)
 131               .append(", readyOps=")
 132               .append(readyOps);
 133         } else {
 134             sb.append(", invalid");
 135         }
 136         return sb.toString();
 137     }
 138 
 139     // used by Selector implementations to record when the key was selected
 140     int lastPolled;
 141 }