org.jboss.netty.channel.socket.oio.OioServerSocketChannelFactory Maven / Gradle / Ivy
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/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package org.jboss.netty.channel.socket.oio;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelSink;
import org.jboss.netty.channel.group.ChannelGroup;
import org.jboss.netty.channel.socket.ServerSocketChannel;
import org.jboss.netty.channel.socket.ServerSocketChannelFactory;
import org.jboss.netty.util.ThreadNameDeterminer;
import org.jboss.netty.util.internal.ExecutorUtil;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionException;
/**
* A {@link ServerSocketChannelFactory} which creates a server-side blocking
* I/O based {@link ServerSocketChannel}. 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.
*
* How threads work
*
* There are two types of threads in a {@link OioServerSocketChannelFactory};
* one is boss thread and the other is worker thread.
*
*
Boss threads
*
* Each bound {@link ServerSocketChannel} has its own boss thread.
* For example, if you opened two server ports such as 80 and 443, you will
* have two boss threads. A boss thread accepts incoming connections until
* the port is unbound. Once a connection is accepted successfully, the boss
* thread passes the accepted {@link Channel} to one of the worker
* threads that the {@link OioServerSocketChannelFactory} manages.
*
*
Worker threads
*
* Each connected {@link Channel} has a dedicated worker thread, just like a
* traditional blocking I/O thread model.
*
*
Life cycle of threads and graceful shutdown
*
* All threads are acquired from the {@link Executor}s which were specified
* when a {@link OioServerSocketChannelFactory} was created. Boss threads are
* acquired from the {@code bossExecutor}, and worker threads are acquired from
* the {@code workerExecutor}. Therefore, you should make sure the specified
* {@link Executor}s are able to lend the sufficient number of threads.
*
* Both boss and worker threads are acquired lazily, and then released when
* there's nothing left to process. All the related resources are also
* released when the boss and worker threads are released. Therefore, to shut
* down a service gracefully, you should do the following:
*
*
* - unbind all channels created by the factory,
*
- close all child channels accepted by the unbound channels,
* (these two steps so far is usually done using {@link ChannelGroup#close()})
* - call {@link #releaseExternalResources()}.
*
*
* 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.
*
* Limitation
*
* A {@link ServerSocketChannel} created by this factory and its child channels
* do not support asynchronous operations. Any I/O requests such as
* {@code "write"} will be performed in a blocking manner.
*
* @apiviz.landmark
*/
public class OioServerSocketChannelFactory implements ServerSocketChannelFactory {
final Executor bossExecutor;
private final Executor workerExecutor;
private final ChannelSink sink;
private boolean shutdownExecutor;
/**
* Create a new {@link OioServerSocketChannelFactory} with a {@link Executors#newCachedThreadPool()}
* for the boss and worker executor.
*
* See {@link #OioServerSocketChannelFactory(Executor, Executor)}
*/
public OioServerSocketChannelFactory() {
this(Executors.newCachedThreadPool(), Executors.newCachedThreadPool());
shutdownExecutor = true;
}
/**
* Creates a new instance.
*
* @param bossExecutor
* the {@link Executor} which will execute the boss threads
* @param workerExecutor
* the {@link Executor} which will execute the I/O worker threads
*/
public OioServerSocketChannelFactory(
Executor bossExecutor, Executor workerExecutor) {
this(bossExecutor, workerExecutor, null);
}
/**
* Creates a new instance.
*
* @param bossExecutor
* the {@link Executor} which will execute the boss threads
* @param workerExecutor
* the {@link Executor} which will execute the I/O worker threads
* @param determiner
* the {@link ThreadNameDeterminer} to set the thread names.
*/
public OioServerSocketChannelFactory(Executor bossExecutor, Executor workerExecutor,
ThreadNameDeterminer determiner) {
if (bossExecutor == null) {
throw new NullPointerException("bossExecutor");
}
if (workerExecutor == null) {
throw new NullPointerException("workerExecutor");
}
this.bossExecutor = bossExecutor;
this.workerExecutor = workerExecutor;
sink = new OioServerSocketPipelineSink(workerExecutor, determiner);
}
public ServerSocketChannel newChannel(ChannelPipeline pipeline) {
return new OioServerSocketChannel(this, pipeline, sink);
}
public void shutdown() {
if (shutdownExecutor) {
ExecutorUtil.shutdownNow(bossExecutor);
ExecutorUtil.shutdownNow(workerExecutor);
}
}
public void releaseExternalResources() {
ExecutorUtil.shutdownNow(bossExecutor);
ExecutorUtil.shutdownNow(workerExecutor);
}
}