/*
* @(#) $Id: SocketAcceptor.java 210062 2005-07-11 03:52:38Z trustin $
*
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.apache.mina.io.socket;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.apache.mina.common.BaseSessionManager;
import org.apache.mina.io.IoAcceptor;
import org.apache.mina.io.IoFilterChain;
import org.apache.mina.io.IoHandler;
import org.apache.mina.io.IoSessionManagerFilterChain;
import org.apache.mina.util.Queue;
/**
* {@link IoAcceptor} for socket transport (TCP/IP).
*
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
* @version $Rev: 210062 $, $Date: 2005-07-11 12:52:38 +0900 $
*/
public class SocketAcceptor extends BaseSessionManager implements IoAcceptor
{
private static volatile int nextId = 0;
private final IoSessionManagerFilterChain filters = new SocketSessionManagerFilterChain( this );
private final int id = nextId ++ ;
private Selector selector;
private final Map channels = new HashMap();
private final Queue registerQueue = new Queue();
private final Queue cancelQueue = new Queue();
private int backlog = 50;
private Worker worker;
/**
* Creates a new instance.
*/
public SocketAcceptor()
{
}
/**
* Binds to the specified <code>address</code> and handles incoming
* connections with the specified <code>handler</code>. Backlog value
* is configured to the value of <code>backlog</code> property.
*
* @throws IOException if failed to bind
*/
public void bind( SocketAddress address, IoHandler handler ) throws IOException
{
if( address == null )
{
throw new NullPointerException( "address" );
}
if( handler == null )
{
throw new NullPointerException( "handler" );
}
if( !( address instanceof InetSocketAddress ) )
{
throw new IllegalArgumentException( "Unexpected address type: " + address.getClass() );
}
if( ( ( InetSocketAddress ) address ).getPort() == 0 )
{
throw new IllegalArgumentException( "Unsupported port number: 0" );
}
RegistrationRequest request = new RegistrationRequest( address, backlog, handler );
synchronized( this )
{
synchronized( registerQueue )
{
registerQueue.push( request );
}
startupWorker();
}
selector.wakeup();
synchronized( request )
{
while( !request.done )
{
try
{
request.wait();
}
catch( InterruptedException e )
{
}
}
}
if( request.exception != null )
{
throw request.exception;
}
}
private synchronized void startupWorker() throws IOException
{
if( worker == null )
{
selector = Selector.open();
worker = new Worker();
worker.start();
}
}
public void unbind( SocketAddress address )
{
if( address == null )
{
throw new NullPointerException( "address" );
}
CancellationRequest request = new CancellationRequest( address );
synchronized( this )
{
try
{
startupWorker();
}
catch( IOException e )
{
// IOException is thrown only when Worker thread is not
// running and failed to open a selector. We simply throw
// IllegalArgumentException here because we can simply
// conclude that nothing is bound to the selector.
throw new IllegalArgumentException( "Address not bound: " + address );
}
synchronized( cancelQueue )
{
cancelQueue.push( request );
}
}
selector.wakeup();
synchronized( request )
{
while( !request.done )
{
try
{
request.wait();
}
catch( InterruptedException e )
{
}
}
}
if( request.exception != null )
{
request.exception.fillInStackTrace();
throw request.exception;
}
}
/**
* Returns the default backlog value which is used when user binds.
*/
public int getBacklog()
{
return backlog;
}
/**
* Sets the default backlog value which is used when user binds.
*/
public void setBacklog( int defaultBacklog )
{
if( defaultBacklog <= 0 )
{
throw new IllegalArgumentException( "defaultBacklog: " + defaultBacklog );
}
this.backlog = defaultBacklog;
}
private class Worker extends Thread
{
public Worker()
{
super( "SocketAcceptor-" + id );
}
public void run()
{
for( ;; )
{
try
{
int nKeys = selector.select();
registerNew();
cancelKeys();
if( nKeys > 0 )
{
processSessions( selector.selectedKeys() );
}
if( selector.keys().isEmpty() )
{
synchronized( SocketAcceptor.this )
{
if( selector.keys().isEmpty() &&
registerQueue.isEmpty() &&
cancelQueue.isEmpty() )
{
worker = null;
try
{
selector.close();
}
catch( IOException e )
{
exceptionMonitor.exceptionCaught( SocketAcceptor.this, e );
}
finally
{
selector = null;
}
break;
}
}
}
}
catch( IOException e )
{
exceptionMonitor.exceptionCaught( SocketAcceptor.this, e );
try
{
Thread.sleep( 1000 );
}
catch( InterruptedException e1 )
{
}
}
}
}
private void processSessions( Set keys ) throws IOException
{
Iterator it = keys.iterator();
while( it.hasNext() )
{
SelectionKey key = ( SelectionKey ) it.next();
it.remove();
if( !key.isAcceptable() )
{
continue;
}
ServerSocketChannel ssc = ( ServerSocketChannel ) key.channel();
SocketChannel ch = ssc.accept();
if( ch == null )
{
continue;
}
boolean success = false;
try
{
RegistrationRequest req = ( RegistrationRequest ) key.attachment();
SocketSession session = new SocketSession( filters, ch, req.handler );
req.handler.sessionCreated( session );
SocketIoProcessor.getInstance().addSession( session );
success = true;
}
catch( Throwable t )
{
exceptionMonitor.exceptionCaught( SocketAcceptor.this, t );
}
finally
{
if( !success )
{
ch.close();
}
}
}
}
}
private void registerNew()
{
if( registerQueue.isEmpty() )
{
return;
}
for( ;; )
{
RegistrationRequest req;
synchronized( registerQueue )
{
req = ( RegistrationRequest ) registerQueue.pop();
}
if( req == null )
{
break;
}
ServerSocketChannel ssc = null;
try
{
ssc = ServerSocketChannel.open();
ssc.configureBlocking( false );
ssc.socket().bind( req.address, req.backlog );
ssc.register( selector, SelectionKey.OP_ACCEPT, req );
channels.put( req.address, ssc );
}
catch( IOException e )
{
req.exception = e;
}
finally
{
synchronized( req )
{
req.done = true;
req.notify();
}
if( ssc != null && req.exception != null )
{
try
{
ssc.close();
}
catch( IOException e )
{
exceptionMonitor.exceptionCaught( this, e );
}
}
}
}
}
private void cancelKeys()
{
if( cancelQueue.isEmpty() )
{
return;
}
for( ;; )
{
CancellationRequest request;
synchronized( cancelQueue )
{
request = ( CancellationRequest ) cancelQueue.pop();
}
if( request == null )
{
break;
}
ServerSocketChannel ssc = ( ServerSocketChannel ) channels.remove( request.address );
// close the channel
try
{
if( ssc == null )
{
request.exception = new IllegalArgumentException( "Address not bound: " + request.address );
}
else
{
SelectionKey key = ssc.keyFor( selector );
key.cancel();
selector.wakeup(); // wake up again to trigger thread death
ssc.close();
}
}
catch( IOException e )
{
exceptionMonitor.exceptionCaught( this, e );
}
finally
{
synchronized( request )
{
request.done = true;
request.notify();
}
}
}
}
public IoFilterChain getFilterChain()
{
return filters;
}
private static class RegistrationRequest
{
private final SocketAddress address;
private final int backlog;
private final IoHandler handler;
private IOException exception;
private boolean done;
private RegistrationRequest( SocketAddress address, int backlog, IoHandler handler )
{
this.address = address;
this.backlog = backlog;
this.handler = handler;
}
}
private static class CancellationRequest
{
private final SocketAddress address;
private boolean done;
private RuntimeException exception;
private CancellationRequest( SocketAddress address )
{
this.address = address;
}
}
}