J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2004 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any 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.net.SocketException; |
| 32 | import java.util.*; |
| 33 | import sun.misc.*; |
| 34 | |
| 35 | |
| 36 | /** |
| 37 | * Base Selector implementation class. |
| 38 | */ |
| 39 | |
| 40 | abstract class SelectorImpl |
| 41 | extends AbstractSelector |
| 42 | { |
| 43 | |
| 44 | // The set of keys with data ready for an operation |
| 45 | protected Set selectedKeys; |
| 46 | |
| 47 | // The set of keys registered with this Selector |
| 48 | protected HashSet keys; |
| 49 | |
| 50 | // Public views of the key sets |
| 51 | private Set publicKeys; // Immutable |
| 52 | private Set publicSelectedKeys; // Removal allowed, but not addition |
| 53 | |
| 54 | protected SelectorImpl(SelectorProvider sp) { |
| 55 | super(sp); |
| 56 | keys = new HashSet(); |
| 57 | selectedKeys = new HashSet(); |
| 58 | if (Util.atBugLevel("1.4")) { |
| 59 | publicKeys = keys; |
| 60 | publicSelectedKeys = selectedKeys; |
| 61 | } else { |
| 62 | publicKeys = Collections.unmodifiableSet(keys); |
| 63 | publicSelectedKeys = Util.ungrowableSet(selectedKeys); |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | public Set keys() { |
| 68 | if (!isOpen() && !Util.atBugLevel("1.4")) |
| 69 | throw new ClosedSelectorException(); |
| 70 | return publicKeys; |
| 71 | } |
| 72 | |
| 73 | public Set selectedKeys() { |
| 74 | if (!isOpen() && !Util.atBugLevel("1.4")) |
| 75 | throw new ClosedSelectorException(); |
| 76 | return publicSelectedKeys; |
| 77 | } |
| 78 | |
| 79 | protected abstract int doSelect(long timeout) throws IOException; |
| 80 | |
| 81 | private int lockAndDoSelect(long timeout) throws IOException { |
| 82 | synchronized (this) { |
| 83 | if (!isOpen()) |
| 84 | throw new ClosedSelectorException(); |
| 85 | synchronized (publicKeys) { |
| 86 | synchronized (publicSelectedKeys) { |
| 87 | return doSelect(timeout); |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | public int select(long timeout) |
| 94 | throws IOException |
| 95 | { |
| 96 | if (timeout < 0) |
| 97 | throw new IllegalArgumentException("Negative timeout"); |
| 98 | return lockAndDoSelect((timeout == 0) ? -1 : timeout); |
| 99 | } |
| 100 | |
| 101 | public int select() throws IOException { |
| 102 | return select(0); |
| 103 | } |
| 104 | |
| 105 | public int selectNow() throws IOException { |
| 106 | return lockAndDoSelect(0); |
| 107 | } |
| 108 | |
| 109 | public void implCloseSelector() throws IOException { |
| 110 | wakeup(); |
| 111 | synchronized (this) { |
| 112 | synchronized (publicKeys) { |
| 113 | synchronized (publicSelectedKeys) { |
| 114 | implClose(); |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | protected abstract void implClose() throws IOException; |
| 121 | |
| 122 | void putEventOps(SelectionKeyImpl sk, int ops) { } |
| 123 | |
| 124 | protected final SelectionKey register(AbstractSelectableChannel ch, |
| 125 | int ops, |
| 126 | Object attachment) |
| 127 | { |
| 128 | if (!(ch instanceof SelChImpl)) |
| 129 | throw new IllegalSelectorException(); |
| 130 | SelectionKeyImpl k = new SelectionKeyImpl((SelChImpl)ch, this); |
| 131 | k.attach(attachment); |
| 132 | synchronized (publicKeys) { |
| 133 | implRegister(k); |
| 134 | } |
| 135 | k.interestOps(ops); |
| 136 | return k; |
| 137 | } |
| 138 | |
| 139 | protected abstract void implRegister(SelectionKeyImpl ski); |
| 140 | |
| 141 | void processDeregisterQueue() throws IOException { |
| 142 | // Precondition: Synchronized on this, keys, and selectedKeys |
| 143 | Set cks = cancelledKeys(); |
| 144 | synchronized (cks) { |
| 145 | Iterator i = cks.iterator(); |
| 146 | while (i.hasNext()) { |
| 147 | SelectionKeyImpl ski = (SelectionKeyImpl)i.next(); |
| 148 | try { |
| 149 | implDereg(ski); |
| 150 | } catch (SocketException se) { |
| 151 | IOException ioe = new IOException( |
| 152 | "Error deregistering key"); |
| 153 | ioe.initCause(se); |
| 154 | throw ioe; |
| 155 | } finally { |
| 156 | i.remove(); |
| 157 | } |
| 158 | } |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | protected abstract void implDereg(SelectionKeyImpl ski) throws IOException; |
| 163 | |
| 164 | abstract public Selector wakeup(); |
| 165 | |
| 166 | } |