/*
* JBoss, Home of Professional Open Source
*
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* by the @author tags. See the COPYRIGHT.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.netty.channel.socket.oio;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.TimeUnit;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFactoryExecutorResource;
import org.jboss.netty.channel.ChannelFactoryResource;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.socket.ClientSocketChannelFactory;
import org.jboss.netty.channel.socket.SocketChannel;
/**
* A {@link ClientSocketChannelFactory} which creates a client-side blocking
* I/O based {@link SocketChannel}. It utilizes the good old blocking I/O API
* which is known to yield better throughput and latency when there are
* relatively small number of connections to serve.
*
* <h3>How threads work</h3>
* <p>
* There is only one type of threads in {@link OioClientSocketChannelFactory};
* worker threads.
*
* <h4>Worker threads</h4>
* <p>
* Each connected {@link Channel} has a dedicated worker thread, just like a
* traditional blocking I/O thread model.
*
* <h3>Life cycle of threads and graceful shutdown</h3>
* TODO: Rewrite this section to recommend a user to call ChannelFactoryResource.release().
* <p>
* Worker threads are acquired from the {@link Executor} which was specified
* when a {@link OioClientSocketChannelFactory} was created (i.e. {@code workerExecutor}.)
* Therefore, you should make sure the specified {@link Executor} is able to
* lend the sufficient number of threads.
* <p>
* Worker threads are acquired lazily, and then released when there's nothing
* left to process. All the related resources are also released when the
* worker threads are released. Therefore, to shut down a service gracefully,
* you should do the following:
*
* <ol>
* <li>close all channels created by the factory,</li>
* <li>call {@link ExecutorService#shutdownNow()} for the executor which was
* specified to create the factory, and</li>
* <li>call {@link ExecutorService#awaitTermination(long, TimeUnit)}
* until it returns {@code true}.</li>
* </ol>
*
* Please make sure not to shut down the executor until all channels are
* closed. Otherwise, you will end up with a {@link RejectedExecutionException}
* and the related resources might not be released properly.
*
* <h3>Limitation</h3>
* <p>
* A {@link SocketChannel} created by this factory does not support asynchronous
* operations. Any I/O requests such as {@code "connect"} and {@code "write"}
* will be performed in a blocking manner.
*
* @author The Netty Project (netty-dev@lists.jboss.org)
* @author Trustin Lee (tlee@redhat.com)
*
* @version $Rev: 520 $, $Date: 2008-11-26 19:30:21 +0900 (Wed, 26 Nov 2008) $
*
* @apiviz.landmark
*/
public class OioClientSocketChannelFactory implements ClientSocketChannelFactory {
private final ChannelFactoryResource externalResource;
final OioClientSocketPipelineSink sink;
/**
* Creates a new instance.
*
* @param workerExecutor
* the {@link Executor} which will execute the I/O worker threads
*/
public OioClientSocketChannelFactory(Executor workerExecutor) {
if (workerExecutor == null) {
throw new NullPointerException("workerExecutor");
}
externalResource = new ChannelFactoryExecutorResource(workerExecutor);
sink = new OioClientSocketPipelineSink(workerExecutor);
}
public SocketChannel newChannel(ChannelPipeline pipeline) {
return new OioClientSocketChannel(this, pipeline, sink);
}
public ChannelFactoryResource getExternalResource() {
return externalResource;
}
}