org.jboss.netty.channel.socket.oio

Class OioDatagramChannelFactory

java.lang.Object

org.jboss.netty.channel.socket.oio.OioDatagramChannelFactory

All Implemented Interfaces:

ChannelFactory, DatagramChannelFactory, ExternalResourceReleasable

public class OioDatagramChannelFactory
extends java.lang.Object
implements DatagramChannelFactory

A DatagramChannelFactory which creates a blocking I/O based DatagramChannel. It utilizes the good old blocking I/O API which has support for multicast.

How threads work

There is only one type of threads in OioDatagramChannelFactory; worker threads.

Worker threads

Each Channel has a dedicated worker thread, just like a traditional blocking I/O thread model.

Life cycle of threads and graceful shutdown

Worker threads are acquired from the Executor which was specified when a OioDatagramChannelFactory was created (i.e. workerExecutor.) Therefore, you should make sure the specified Executor is able to lend the sufficient number of threads.

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:

1. close all channels created by the factory usually using ChannelGroup.close(), and
2. call releaseExternalResources().

Please make sure not to shut down the executor until all channels are closed. Otherwise, you will end up with a RejectedExecutionException and the related resources might not be released properly.

Limitation

A DatagramChannel created by this factory does not support asynchronous operations. Any I/O requests such as "write" will be performed in a blocking manner.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	shutdownExecutor
(package private) OioDatagramPipelineSink	sink
private java.util.concurrent.Executor	workerExecutor

Constructor Summary

Constructors

Constructor and Description
OioDatagramChannelFactory() Creates a new instance with a Executors.newCachedThreadPool() See OioDatagramChannelFactory(Executor)
OioDatagramChannelFactory(java.util.concurrent.Executor workerExecutor) Creates a new instance.
OioDatagramChannelFactory(java.util.concurrent.Executor workerExecutor, ThreadNameDeterminer determiner) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
DatagramChannel	newChannel(ChannelPipeline pipeline) Creates and opens a new Channel and attaches the specified ChannelPipeline to the new Channel.
void	releaseExternalResources() Releases the external resources that this factory depends on to function.
void	shutdown() Shudown the ChannelFactory and all the resource it created internal.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

workerExecutor

private final java.util.concurrent.Executor workerExecutor

sink

final OioDatagramPipelineSink sink

shutdownExecutor

private boolean shutdownExecutor

Constructor Detail

OioDatagramChannelFactory

public OioDatagramChannelFactory()

Creates a new instance with a Executors.newCachedThreadPool() See OioDatagramChannelFactory(Executor)

OioDatagramChannelFactory

public OioDatagramChannelFactory(java.util.concurrent.Executor workerExecutor)

Creates a new instance.

Parameters:

workerExecutor - the Executor which will execute the I/O worker threads

OioDatagramChannelFactory

public OioDatagramChannelFactory(java.util.concurrent.Executor workerExecutor,
                                 ThreadNameDeterminer determiner)

Creates a new instance.

Parameters:

workerExecutor - the Executor which will execute the I/O worker threads

determiner - the ThreadNameDeterminer to set the thread names.

Method Detail

newChannel

public DatagramChannel newChannel(ChannelPipeline pipeline)

Description copied from interface: ChannelFactory

Creates and opens a new Channel and attaches the specified ChannelPipeline to the new Channel.

Specified by:

newChannel in interface ChannelFactory

Specified by:

newChannel in interface DatagramChannelFactory

Parameters:

pipeline - the ChannelPipeline which is going to be attached to the new Channel

Returns:

the newly open channel

shutdown

public void shutdown()

Description copied from interface: ChannelFactory

Shudown the ChannelFactory and all the resource it created internal.

Specified by:

shutdown in interface ChannelFactory

releaseExternalResources

public void releaseExternalResources()

Description copied from interface: ChannelFactory

Releases the external resources that this factory depends on to function. An external resource is a resource that this factory didn't create by itself. For example, Executors that you specified in the factory constructor are external resources. You can call this method to release all external resources conveniently when the resources are not used by this factory or any other part of your application. An unexpected behavior will be resulted in if the resources are released when there's an open channel which is managed by this factory. This will also call ChannelFactory.shutdown() before do any action

Specified by:

releaseExternalResources in interface ChannelFactory

Specified by:

releaseExternalResources in interface ExternalResourceReleasable