org.apache.axis2.transport.udp
Class IODispatcher

java.lang.Object
  org.apache.axis2.transport.udp.IODispatcher

All Implemented Interfaces:

java.lang.Runnable, DatagramDispatcher<Endpoint>

public class IODispatcher
extends java.lang.Object
implements DatagramDispatcher<Endpoint>, java.lang.Runnable

I/O dispatcher for incoming UDP packets. This class is responsible for receiving UDP packets and dispatch the processing of these packets to worker threads. It uses a Selector to receive packets from multiple endpoints and a WorkerPool to dispatch the processing tasks.

The dispatcher uses the following thread model: Incoming packets for all the registered endpoints are received in the thread that executes the run() method. For every packet received, a ProcessPacketTask instance is created and dispatched to a worker thread from the configured pool.

The methods addEndpoint(Endpoint), #removeEndpoint(String) and stop() are thread safe and may be called from any thread. However, to avoid concurrency issues, the operation on the underlying Selector will always be executed by the thread executing the run() method. The three methods mentioned above will block until the operation has completed.

Constructor Summary

IODispatcher(DatagramDispatcherCallback callback)
Constructor.

Method Summary

void	addEndpoint(Endpoint endpoint) Add a new endpoint.
void	removeEndpoint(Endpoint endpoint) Remove an endpoint.
void	run() Run the I/O dispatcher.
void	stop() Stop the dispatcher.

Methods inherited from class java.lang.Object

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

Constructor Detail

IODispatcher

public IODispatcher(DatagramDispatcherCallback callback)
             throws java.io.IOException

Constructor.

Parameters:

callback -

Throws:

java.io.IOException - if the Selector instance could not be created

Method Detail

addEndpoint

public void addEndpoint(Endpoint endpoint)
                 throws java.io.IOException

Add a new endpoint. This method creates a new socket listening on the UDP port specified in the endpoint description and makes sure that incoming packets are routed to the specified service.

Specified by:

addEndpoint in interface DatagramDispatcher<Endpoint>

Parameters:

endpoint - the endpoint description

Throws:

java.io.IOException - if the socket could not be created or registered with the selector

removeEndpoint

public void removeEndpoint(Endpoint endpoint)
                    throws java.io.IOException

Remove an endpoint. This causes the corresponding UDP socket to be closed.

Specified by:

removeEndpoint in interface DatagramDispatcher<Endpoint>

Parameters:

endpoint - the endpoint description

Throws:

java.io.IOException - if an error occurred when closing the socket

stop

public void stop()
          throws java.io.IOException

Stop the dispatcher. This method closes all sockets and causes the execution of the run() method to stop.

Specified by:

stop in interface DatagramDispatcher<Endpoint>

Throws:

java.io.IOException

run

public void run()

Run the I/O dispatcher. This method contains the event loop that polls the selector, reads the incoming packets and dispatches the work. It only returns when stop() is called.

Specified by:

run in interface java.lang.Runnable