J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005-2007 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.util.*; |
| 32 | import sun.misc.*; |
| 33 | |
| 34 | |
| 35 | /** |
| 36 | * An implementation of Selector for Linux 2.6+ kernels that uses |
| 37 | * the epoll event notification facility. |
| 38 | */ |
| 39 | class EPollSelectorImpl |
| 40 | extends SelectorImpl |
| 41 | { |
| 42 | |
| 43 | // File descriptors used for interrupt |
| 44 | protected int fd0; |
| 45 | protected int fd1; |
| 46 | |
| 47 | // The poll object |
| 48 | EPollArrayWrapper pollWrapper; |
| 49 | |
| 50 | // Maps from file descriptors to keys |
| 51 | private HashMap fdToKey; |
| 52 | |
| 53 | // True if this Selector has been closed |
| 54 | private boolean closed = false; |
| 55 | |
| 56 | // Lock for interrupt triggering and clearing |
| 57 | private Object interruptLock = new Object(); |
| 58 | private boolean interruptTriggered = false; |
| 59 | |
| 60 | /** |
| 61 | * Package private constructor called by factory method in |
| 62 | * the abstract superclass Selector. |
| 63 | */ |
| 64 | EPollSelectorImpl(SelectorProvider sp) { |
| 65 | super(sp); |
| 66 | int[] fdes = new int[2]; |
| 67 | IOUtil.initPipe(fdes, false); |
| 68 | fd0 = fdes[0]; |
| 69 | fd1 = fdes[1]; |
| 70 | pollWrapper = new EPollArrayWrapper(); |
| 71 | pollWrapper.initInterrupt(fd0, fd1); |
| 72 | fdToKey = new HashMap(); |
| 73 | } |
| 74 | |
| 75 | protected int doSelect(long timeout) |
| 76 | throws IOException |
| 77 | { |
| 78 | if (closed) |
| 79 | throw new ClosedSelectorException(); |
| 80 | processDeregisterQueue(); |
| 81 | try { |
| 82 | begin(); |
| 83 | pollWrapper.poll(timeout); |
| 84 | } finally { |
| 85 | end(); |
| 86 | } |
| 87 | processDeregisterQueue(); |
| 88 | int numKeysUpdated = updateSelectedKeys(); |
| 89 | if (pollWrapper.interrupted()) { |
| 90 | // Clear the wakeup pipe |
| 91 | pollWrapper.putEventOps(pollWrapper.interruptedIndex(), 0); |
| 92 | synchronized (interruptLock) { |
| 93 | pollWrapper.clearInterrupted(); |
| 94 | IOUtil.drain(fd0); |
| 95 | interruptTriggered = false; |
| 96 | } |
| 97 | } |
| 98 | return numKeysUpdated; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Update the keys whose fd's have been selected by the epoll. |
| 103 | * Add the ready keys to the ready queue. |
| 104 | */ |
| 105 | private int updateSelectedKeys() { |
| 106 | int entries = pollWrapper.updated; |
| 107 | int numKeysUpdated = 0; |
| 108 | for (int i=0; i<entries; i++) { |
| 109 | int nextFD = pollWrapper.getDescriptor(i); |
| 110 | SelectionKeyImpl ski = (SelectionKeyImpl) fdToKey.get( |
| 111 | new Integer(nextFD)); |
| 112 | // ski is null in the case of an interrupt |
| 113 | if (ski != null) { |
| 114 | int rOps = pollWrapper.getEventOps(i); |
| 115 | if (selectedKeys.contains(ski)) { |
| 116 | if (ski.channel.translateAndSetReadyOps(rOps, ski)) { |
| 117 | numKeysUpdated++; |
| 118 | } |
| 119 | } else { |
| 120 | ski.channel.translateAndSetReadyOps(rOps, ski); |
| 121 | if ((ski.nioReadyOps() & ski.nioInterestOps()) != 0) { |
| 122 | selectedKeys.add(ski); |
| 123 | numKeysUpdated++; |
| 124 | } |
| 125 | } |
| 126 | } |
| 127 | } |
| 128 | return numKeysUpdated; |
| 129 | } |
| 130 | |
| 131 | protected void implClose() throws IOException { |
| 132 | if (!closed) { |
| 133 | closed = true; |
| 134 | |
| 135 | // prevent further wakeup |
| 136 | synchronized (interruptLock) { |
| 137 | interruptTriggered = true; |
| 138 | } |
| 139 | |
| 140 | FileDispatcher.closeIntFD(fd0); |
| 141 | FileDispatcher.closeIntFD(fd1); |
| 142 | if (pollWrapper != null) { |
| 143 | |
| 144 | pollWrapper.release(fd0); |
| 145 | pollWrapper.closeEPollFD(); |
| 146 | pollWrapper = null; |
| 147 | selectedKeys = null; |
| 148 | |
| 149 | // Deregister channels |
| 150 | Iterator i = keys.iterator(); |
| 151 | while (i.hasNext()) { |
| 152 | SelectionKeyImpl ski = (SelectionKeyImpl)i.next(); |
| 153 | deregister(ski); |
| 154 | SelectableChannel selch = ski.channel(); |
| 155 | if (!selch.isOpen() && !selch.isRegistered()) |
| 156 | ((SelChImpl)selch).kill(); |
| 157 | i.remove(); |
| 158 | } |
| 159 | } |
| 160 | fd0 = -1; |
| 161 | fd1 = -1; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | protected void implRegister(SelectionKeyImpl ski) { |
| 166 | int fd = IOUtil.fdVal(ski.channel.getFD()); |
| 167 | fdToKey.put(new Integer(fd), ski); |
| 168 | pollWrapper.add(fd); |
| 169 | keys.add(ski); |
| 170 | } |
| 171 | |
| 172 | protected void implDereg(SelectionKeyImpl ski) throws IOException { |
| 173 | assert (ski.getIndex() >= 0); |
| 174 | int fd = ski.channel.getFDVal(); |
| 175 | fdToKey.remove(new Integer(fd)); |
| 176 | pollWrapper.release(fd); |
| 177 | ski.setIndex(-1); |
| 178 | keys.remove(ski); |
| 179 | selectedKeys.remove(ski); |
| 180 | deregister((AbstractSelectionKey)ski); |
| 181 | SelectableChannel selch = ski.channel(); |
| 182 | if (!selch.isOpen() && !selch.isRegistered()) |
| 183 | ((SelChImpl)selch).kill(); |
| 184 | } |
| 185 | |
| 186 | void putEventOps(SelectionKeyImpl sk, int ops) { |
| 187 | int fd = IOUtil.fdVal(sk.channel.getFD()); |
| 188 | pollWrapper.setInterest(fd, ops); |
| 189 | } |
| 190 | |
| 191 | public Selector wakeup() { |
| 192 | synchronized (interruptLock) { |
| 193 | if (!interruptTriggered) { |
| 194 | pollWrapper.interrupt(); |
| 195 | interruptTriggered = true; |
| 196 | } |
| 197 | } |
| 198 | return this; |
| 199 | } |
| 200 | |
| 201 | static { |
| 202 | Util.load(); |
| 203 | } |
| 204 | |
| 205 | } |