org.jenkinsci.remoting.nio

Class NioChannelHub

java.lang.Object

org.jenkinsci.remoting.nio.NioChannelHub

All Implemented Interfaces:

Closeable, AutoCloseable, Runnable

public class NioChannelHub
extends Object
implements Runnable, Closeable

Switch board of multiple Channels through NIO select. Through this hub, N threads can attend to M channels with a help of one selector thread.

To get the selector thread going, call the run() method from a thread after you instantiate this object. The run() method will block until the hub gets closed.

Since:

2.38

Author:

Kohsuke Kawaguchi

Constructor Summary

Constructors

Constructor and Description
NioChannelHub(ExecutorService commandProcessor)

Method Summary

Modifier and Type	Method and Description
void	close() Shuts down the selector thread and aborts all
void	ensureValid() Verifies that the selector thread is running and this hub is active.
Selector	getSelector()
NioChannelBuilder	newChannelBuilder(String name, ExecutorService es) Returns a ChannelBuilder that will add a channel to this hub.
protected void	onSelected(SelectionKey key) Called when the unknown key registered to the selector is selected.
void	run() Attend to channels in the hub.
void	setFrameSize(int sz)

Methods inherited from class java.lang.Object

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

Constructor Detail

NioChannelHub

public NioChannelHub(ExecutorService commandProcessor)
              throws IOException

Parameters:

commandProcessor - Executor pool that delivers received command packets to AbstractByteArrayCommandTransport.ByteArrayReceiver. This pool will handle the deserialization (which may block due to classloading from the other side).

Throws:

IOException

Method Detail

setFrameSize

public void setFrameSize(int sz)

newChannelBuilder

public NioChannelBuilder newChannelBuilder(String name,
                                           ExecutorService es)

Returns a ChannelBuilder that will add a channel to this hub.

If the way the channel is built doesn't support NIO, the resulting Channel will use a separate thread to service its I/O.

close

public void close()
           throws IOException

Shuts down the selector thread and aborts all

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

run

public void run()

Attend to channels in the hub. This method returns when close() is called and the selector is shut down.

Specified by:

run in interface Runnable

onSelected

protected void onSelected(SelectionKey key)

Called when the unknown key registered to the selector is selected.

getSelector

public Selector getSelector()

ensureValid

public void ensureValid()
                 throws IOException

Verifies that the selector thread is running and this hub is active. Several bugs have been reported (such as JENKINS-24050) that causes the selector thread to die, and several more bugs have been reported (such as JENKINS-24155 and JENKINS-24201) that are suspected to be caused by the death of NIO selector thread. This check makes it easier to find this problem and report why the selector thread has died.

Throws:

IOException