Mercurial > hg > blitz_stable
diff src/com/go/trove/net/DistributedSocketFactory.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/com/go/trove/net/DistributedSocketFactory.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,383 @@ +/* ==================================================================== + * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group + * ==================================================================== + * The Tea Software License, Version 1.1 + * + * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. The end-user documentation included with the redistribution, + * if any, must include the following acknowledgment: + * "This product includes software developed by the + * Walt Disney Internet Group (http://opensource.go.com/)." + * Alternately, this acknowledgment may appear in the software itself, + * if and wherever such third-party acknowledgments normally appear. + * + * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must + * not be used to endorse or promote products derived from this + * software without prior written permission. For written + * permission, please contact opensource@dig.com. + * + * 5. Products derived from this software may not be called "Tea", + * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", + * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior + * written permission of the Walt Disney Internet Group. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY + * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * For more information about Tea, please see http://opensource.go.com/. + */ + +package com.go.trove.net; + +import java.io.*; +import java.net.*; +import java.util.*; +import java.lang.ref.*; +import com.go.trove.util.IdentityMap; + +/****************************************************************************** + * A SocketFactory implementation for distributing load among several + * SocketFactories. If an exception occurs on a socket, its pool is put into + * the "dead" list. A special thread will run in the background, trying to + * resurrect the dead SocketSocket. As soon as its able to create sockets + * again, its added back into the "live" list. + * <p> + * Consider wrapping with a {@link LazySocketFactory} for automatic checking + * against socket factories that may be dead. + * + * @author Brian S O'Neill + * @version + * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 01/01/22 <!-- $--> + */ +public class DistributedSocketFactory implements SocketFactory { + private final long mTimeout; + + private int mFactoryIndex; + + // Contains only the live SocketFactories. + private List mFactories; + + // Maps SocketPools to resurrector threads. + private Map mResurrectors; + + // Maps CheckedSockets to the SocketPools that they came from. + private Map mSocketSources; + + private CheckedSocket.ExceptionListener mListener; + + /** + * @param timeout Maximum time to wait (in milliseconds) for new + * connections to be established before throwing an exception + */ + public DistributedSocketFactory(long timeout) { + mTimeout = timeout; + mFactories = Collections.synchronizedList(new ArrayList()); + mResurrectors = Collections.synchronizedMap(new HashMap()); + mSocketSources = Collections.synchronizedMap(new IdentityMap()); + + mListener = new CheckedSocket.ExceptionListener() { + public void exceptionOccurred(CheckedSocket s, Exception e, int count) { + if (count == 1) { + deadFactory((SocketFactory)mSocketSources.get(s)); + } + } + }; + } + + public void addSocketFactory(SocketFactory factory) { + mFactories.add(factory); + } + + public void removeSocketFactory(SocketFactory factory) { + mFactories.remove(factory); + Thread t = (Thread)mResurrectors.remove(factory); + if (t != null) { + t.interrupt(); + } + } + + public InetAddressAndPort getInetAddressAndPort() { + try { + return getFactory(selectFactory(null)).getInetAddressAndPort(); + } + catch (ConnectException e) { + return InetAddressAndPort.UNKNOWN; + } + } + + public InetAddressAndPort getInetAddressAndPort(Object session) { + try { + return getFactory(selectFactory(session)) + .getInetAddressAndPort(session); + } + catch (ConnectException e) { + return InetAddressAndPort.UNKNOWN; + } + } + + public long getDefaultTimeout() { + return mTimeout; + } + + public CheckedSocket createSocket() + throws ConnectException, SocketException + { + return createSocket(null, mTimeout); + } + + public CheckedSocket createSocket(Object session) + throws ConnectException, SocketException + { + return createSocket(session, mTimeout); + } + + public CheckedSocket createSocket(long timeout) + throws ConnectException, SocketException + { + return createSocket(null, timeout); + } + + public CheckedSocket createSocket(Object session, long timeout) + throws ConnectException, SocketException + { + long startTime = timeout > 0 ? System.currentTimeMillis() : 0; + int index = selectFactory(session); + int count = mFactories.size(); + + for (int i=0; i<count; i++) { + SocketFactory factory = null; + try { + factory = getFactory(index++); + CheckedSocket socket = factory.createSocket(session, timeout); + socket.addExceptionListener(mListener); + mSocketSources.put(socket, factory); + return socket; + } + catch (SocketException e) { + deadFactory(factory); + + if (timeout == 0) { + throw e; + } + + if (timeout > 0) { + timeout -= (System.currentTimeMillis() - startTime); + if (timeout < 0) { + throw e; + } + } + } + } + + throw new ConnectException("Unable to create socket"); + } + + public CheckedSocket getSocket() throws ConnectException, SocketException { + return getSocket(null, mTimeout); + } + + public CheckedSocket getSocket(Object session) + throws ConnectException, SocketException + { + return getSocket(session, mTimeout); + } + + public CheckedSocket getSocket(long timeout) + throws ConnectException, SocketException + { + return getSocket(null, timeout); + } + + public CheckedSocket getSocket(Object session, long timeout) + throws ConnectException, SocketException + { + long startTime = timeout > 0 ? System.currentTimeMillis() : 0; + int index = selectFactory(session); + int count = mFactories.size(); + + for (int i=0; i<count; i++) { + SocketFactory factory = null; + try { + factory = getFactory(index++); + CheckedSocket socket = factory.getSocket(session, timeout); + socket.addExceptionListener(mListener); + mSocketSources.put(socket, factory); + return socket; + } + catch (SocketException e) { + deadFactory(factory); + + if (timeout == 0) { + throw e; + } + + if (timeout > 0) { + timeout -= (System.currentTimeMillis() - startTime); + if (timeout < 0) { + throw e; + } + } + } + } + + throw new ConnectException("Unable to get socket"); + } + + public void recycleSocket(CheckedSocket socket) + throws SocketException, IllegalArgumentException + { + if (socket == null) { + return; + } + + SocketFactory source = (SocketFactory)mSocketSources.remove(socket); + + if (source == null) { + throw new IllegalArgumentException + ("Socket did not originate from this pool"); + } + + socket.removeExceptionListener(mListener); + source.recycleSocket(socket); + } + + public void clear() { + synchronized (mFactories) { + for (int i = mFactories.size(); --i >= 0; ) { + ((SocketFactory)mFactories.get(i)).clear(); + } + } + } + + public int getAvailableCount() { + int count = 0; + synchronized (mFactories) { + for (int i = mFactories.size(); --i >= 0; ) { + count += ((SocketFactory)mFactories.get(i)) + .getAvailableCount(); + } + } + return count; + } + + /** + * The provided index must be positive, but it can be out of the factory + * list bounds. + */ + private SocketFactory getFactory(int index) throws ConnectException { + synchronized (mFactories) { + int size = mFactories.size(); + if (size <= 0) { + throw new ConnectException("No SocketFactories available"); + } + return (SocketFactory)mFactories.get(index % size); + } + } + + /** + * Returns an index which is positive, but may be out of the factory list + * bounds. + */ + private int selectFactory(Object session) throws ConnectException { + if (session != null) { + return session.hashCode() & 0x7fffffff; + } + else { + synchronized (mFactories) { + return mFactoryIndex++ & 0x7fffffff; + } + } + } + + private void deadFactory(SocketFactory factory) { + if (factory == null) { + return; + } + + synchronized (mFactories) { + // Only remove factory if its not the last one left. + if (mFactories.contains(factory) && mFactories.size() > 1) { + mFactories.remove(factory); + + Resurrector r = new Resurrector(this, factory); + Thread t = new Thread(null, r, "Resurrector " + + factory.getInetAddressAndPort()); + t.setDaemon(true); + t.start(); + mResurrectors.put(factory, t); + } + } + } + + private static class Resurrector implements Runnable { + // Weakly references owner so that this thread won't prevent it from + // being garbage collected. + private final Reference mOwner; + private final SocketFactory mFactory; + + public Resurrector(DistributedSocketFactory owner, + SocketFactory factory) { + mOwner = new WeakReference(owner); + mFactory = factory; + } + + public void run() { + DistributedSocketFactory owner = null; + try { + while (!Thread.interrupted()) { + owner = (DistributedSocketFactory)mOwner.get(); + if (owner == null) { + break; + } + + try { + mFactory.recycleSocket(mFactory.createSocket()); + owner.mFactories.add(mFactory); + break; + } + catch (IOException e) { + } + + owner = null; + + // Wait at 5 seconds before trying again. + try { + Thread.sleep(5000); + } + catch (InterruptedException e) { + break; + } + } + } + finally { + owner = (DistributedSocketFactory)mOwner.get(); + if (owner != null) { + owner.mResurrectors.remove(mFactory); + } + } + } + } +}