/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.apache.mina.transport.socket.nio;
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.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.mina.common.ExceptionMonitor;
import org.apache.mina.common.IoAcceptor;
import org.apache.mina.common.IoHandler;
import org.apache.mina.common.IoServiceConfig;
import org.apache.mina.common.support.BaseIoAcceptor;
import org.apache.mina.util.Queue;
import org.apache.mina.util.NewThreadExecutor;
import org.apache.mina.util.NamePreservingRunnable;
import edu.emory.mathcs.backport.java.util.concurrent.Executor;
/**
* {@link IoAcceptor} for socket transport (TCP/IP).
*
* @author The Apache Directory Project (mina-dev@directory.apache.org)
* @version $Rev: 389042 $, $Date: 2006-03-27 07:49:41Z $
*/
public class SocketAcceptor extends BaseIoAcceptor
{
/**
* @noinspection StaticNonFinalField
*/
private static volatile int nextId = 0;
private final Executor executor;
private final Object lock = new Object();
private final int id = nextId ++;
private final String threadName = "SocketAcceptor-" + id;
private SocketAcceptorConfig defaultConfig = new SocketAcceptorConfig();
private final Map channels = new HashMap();
private final Queue registerQueue = new Queue();
private final Queue cancelQueue = new Queue();
private final SocketIoProcessor[] ioProcessors;
private final int processorCount;
/**
* @noinspection FieldAccessedSynchronizedAndUnsynchronized
*/
private Selector selector;
private Worker worker;
private int processorDistributor = 0;
/**
* Create an acceptor with a single processing thread using a NewThreadExecutor
*/
public SocketAcceptor()
{
this( 1, new NewThreadExecutor() );
}
/**
* Create an acceptor with the desired number of processing threads
*
* @param processorCount Number of processing threads
* @param executor Executor to use for launching threads
*/
public SocketAcceptor( int processorCount, Executor executor )
{
if( processorCount < 1 )
{
throw new IllegalArgumentException( "Must have at least one processor" );
}
this.executor = executor;
this.processorCount = processorCount;
ioProcessors = new SocketIoProcessor[processorCount];
for( int i = 0; i < processorCount; i++ )
{
ioProcessors[i] = new SocketIoProcessor( "SocketAcceptorIoProcessor-" + id + "." + i, executor );
}
}
/**
* 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, IoServiceConfig config ) throws IOException
{
if( handler == null )
{
throw new NullPointerException( "handler" );
}
if( address != null && !( address instanceof InetSocketAddress ) )
{
throw new IllegalArgumentException( "Unexpected address type: " + address.getClass() );
}
if( config == null )
{
config = getDefaultConfig();
}
RegistrationRequest request = new RegistrationRequest( address, handler, config );
synchronized( registerQueue )
{
registerQueue.push( request );
}
startupWorker();
selector.wakeup();
synchronized( request )
{
while( !request.done )
{
try
{
request.wait();
}
catch( InterruptedException e )
{
ExceptionMonitor.getInstance().exceptionCaught( e );
}
}
}
if( request.exception != null )
{
throw request.exception;
}
}
private synchronized void startupWorker() throws IOException
{
synchronized( lock )
{
if( worker == null )
{
selector = Selector.open();
worker = new Worker();
executor.execute( new NamePreservingRunnable( worker ) );
}
}
}
public void unbind( SocketAddress address )
{
if( address == null )
{
throw new NullPointerException( "address" );
}
CancellationRequest request = new CancellationRequest( address );
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 )
{
ExceptionMonitor.getInstance().exceptionCaught( e );
}
}
}
if( request.exception != null )
{
request.exception.fillInStackTrace();
throw request.exception;
}
}
public void unbindAll()
{
List addresses;
synchronized( channels )
{
addresses = new ArrayList( channels.keySet() );
}
for( Iterator i = addresses.iterator(); i.hasNext(); )
{
unbind( ( SocketAddress ) i.next() );
}
}
private class Worker implements Runnable
{
public void run()
{
Thread.currentThread().setName(SocketAcceptor.this.threadName );
for( ; ; )
{
try
{
int nKeys = selector.select();
registerNew();
if( nKeys > 0 )
{
processSessions( selector.selectedKeys() );
}
cancelKeys();
if( selector.keys().isEmpty() )
{
synchronized( lock )
{
if( selector.keys().isEmpty() &&
registerQueue.isEmpty() &&
cancelQueue.isEmpty() )
{
worker = null;
try
{
selector.close();
}
catch( IOException e )
{
ExceptionMonitor.getInstance().exceptionCaught( e );
}
finally
{
selector = null;
}
break;
}
}
}
}
catch( IOException e )
{
ExceptionMonitor.getInstance().exceptionCaught( e );
try
{
Thread.sleep( 1000 );
}
catch( InterruptedException e1 )
{
ExceptionMonitor.getInstance().exceptionCaught( 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();
SocketSessionImpl session = new SocketSessionImpl(
SocketAcceptor.this, nextProcessor(), getListeners(),
req.config, ch, req.handler, req.address );
getFilterChainBuilder().buildFilterChain( session.getFilterChain() );
req.config.getFilterChainBuilder().buildFilterChain( session.getFilterChain() );
req.config.getThreadModel().buildFilterChain( session.getFilterChain() );
session.getIoProcessor().addNew( session );
success = true;
}
catch( Throwable t )
{
ExceptionMonitor.getInstance().exceptionCaught( t );
}
finally
{
if( !success )
{
ch.close();
}
}
}
}
}
private SocketIoProcessor nextProcessor()
{
return ioProcessors[processorDistributor++ % processorCount];
}
public IoServiceConfig getDefaultConfig()
{
return defaultConfig;
}
/**
* Sets the config this acceptor will use by default.
*
* @param defaultConfig the default config.
* @throws NullPointerException if the specified value is <code>null</code>.
*/
public void setDefaultConfig( SocketAcceptorConfig defaultConfig )
{
if( defaultConfig == null )
{
throw new NullPointerException( "defaultConfig" );
}
this.defaultConfig = defaultConfig;
}
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 );
// Configure the server socket,
SocketAcceptorConfig cfg;
if( req.config instanceof SocketAcceptorConfig )
{
cfg = ( SocketAcceptorConfig ) req.config;
}
else
{
cfg = ( SocketAcceptorConfig ) getDefaultConfig();
}
ssc.socket().setReuseAddress( cfg.isReuseAddress() );
ssc.socket().setReceiveBufferSize(
( ( SocketSessionConfig ) cfg.getSessionConfig() ).getReceiveBufferSize() );
// and bind.
ssc.socket().bind( req.address, cfg.getBacklog() );
if( req.address == null || req.address.getPort() == 0 )
{
req.address = ( InetSocketAddress ) ssc.socket().getLocalSocketAddress();
}
ssc.register( selector, SelectionKey.OP_ACCEPT, req );
synchronized( channels )
{
channels.put( req.address, ssc );
}
getListeners().fireServiceActivated(
this, req.address, req.handler, req.config );
}
catch( IOException e )
{
req.exception = e;
}
finally
{
synchronized( req )
{
req.done = true;
req.notifyAll();
}
if( ssc != null && req.exception != null )
{
try
{
ssc.close();
}
catch( IOException e )
{
ExceptionMonitor.getInstance().exceptionCaught( e );
}
}
}
}
}
private void cancelKeys()
{
if( cancelQueue.isEmpty() )
{
return;
}
for( ; ; )
{
CancellationRequest request;
synchronized( cancelQueue )
{
request = ( CancellationRequest ) cancelQueue.pop();
}
if( request == null )
{
break;
}
ServerSocketChannel ssc;
synchronized( channels )
{
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 );
request.registrationRequest = ( RegistrationRequest ) key.attachment();
key.cancel();
selector.wakeup(); // wake up again to trigger thread death
ssc.close();
}
}
catch( IOException e )
{
ExceptionMonitor.getInstance().exceptionCaught( e );
}
finally
{
synchronized( request )
{
request.done = true;
request.notifyAll();
}
if( request.exception == null )
{
getListeners().fireServiceDeactivated(
this, request.address,
request.registrationRequest.handler,
request.registrationRequest.config );
}
}
}
}
private static class RegistrationRequest
{
private InetSocketAddress address;
private final IoHandler handler;
private final IoServiceConfig config;
private IOException exception;
private boolean done;
private RegistrationRequest( SocketAddress address, IoHandler handler, IoServiceConfig config )
{
this.address = ( InetSocketAddress ) address;
this.handler = handler;
this.config = config;
}
}
private static class CancellationRequest
{
private final SocketAddress address;
private boolean done;
private RegistrationRequest registrationRequest;
private RuntimeException exception;
private CancellationRequest( SocketAddress address )
{
this.address = address;
}
}
}