// ========================================================================
// Copyright (c) 2003-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
package org.eclipse.jetty.server.nio;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.nio.channels.SelectionKey;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import org.eclipse.jetty.continuation.Continuation;
import org.eclipse.jetty.io.AsyncEndPoint;
import org.eclipse.jetty.io.ConnectedEndPoint;
import org.eclipse.jetty.io.Connection;
import org.eclipse.jetty.io.EndPoint;
import org.eclipse.jetty.io.nio.AsyncConnection;
import org.eclipse.jetty.io.nio.SelectChannelEndPoint;
import org.eclipse.jetty.io.nio.SelectorManager;
import org.eclipse.jetty.io.nio.SelectorManager.SelectSet;
import org.eclipse.jetty.server.AsyncHttpConnection;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.util.thread.ThreadPool;
/* ------------------------------------------------------------------------------- */
/**
* Selecting NIO connector.
* <p>
* This connector uses efficient NIO buffers with a non blocking threading model. Direct NIO buffers
* are used and threads are only allocated to connections with requests. Synchronization is used to
* simulate blocking for the servlet API, and any unflushed content at the end of request handling
* is written asynchronously.
* </p>
* <p>
* This connector is best used when there are a many connections that have idle periods.
* </p>
* <p>
* When used with {@link org.eclipse.jetty.continuation.Continuation}, threadless waits are supported.
* If a filter or servlet returns after calling {@link Continuation#suspend()} or when a
* runtime exception is thrown from a call to {@link Continuation#undispatch()}, Jetty will
* will not send a response to the client. Instead the thread is released and the Continuation is
* placed on the timer queue. If the Continuation timeout expires, or it's
* resume method is called, then the request is again allocated a thread and the request is retried.
* The limitation of this approach is that request content is not available on the retried request,
* thus if possible it should be read after the continuation or saved as a request attribute or as the
* associated object of the Continuation instance.
* </p>
*
* @org.apache.xbean.XBean element="nioConnector" description="Creates an NIO based socket connector"
*/
public class SelectChannelConnector extends AbstractNIOConnector
{
protected ServerSocketChannel _acceptChannel;
private int _lowResourcesConnections;
private int _lowResourcesMaxIdleTime;
private int _localPort=-1;
private final SelectorManager _manager = new ConnectorSelectorManager();
/* ------------------------------------------------------------------------------- */
/**
* Constructor.
*
*/
public SelectChannelConnector()
{
_manager.setMaxIdleTime(getMaxIdleTime());
addBean(_manager,true);
setAcceptors(Math.max(1,(Runtime.getRuntime().availableProcessors()+3)/4));
}
@Override
public void setThreadPool(ThreadPool pool)
{
super.setThreadPool(pool);
// preserve start order
removeBean(_manager);
addBean(_manager,true);
}
/* ------------------------------------------------------------ */
@Override
public void accept(int acceptorID) throws IOException
{
ServerSocketChannel server;
synchronized(this)
{
server = _acceptChannel;
}
if (server!=null && server.isOpen() && _manager.isStarted())
{
SocketChannel channel = server.accept();
channel.configureBlocking(false);
Socket socket = channel.socket();
configure(socket);
_manager.register(channel);
}
}
/* ------------------------------------------------------------ */
public void close() throws IOException
{
synchronized(this)
{
if (_acceptChannel != null)
{
removeBean(_acceptChannel);
if (_acceptChannel.isOpen())
_acceptChannel.close();
}
_acceptChannel = null;
_localPort=-2;
}
}
/* ------------------------------------------------------------------------------- */
@Override
public void customize(EndPoint endpoint, Request request) throws IOException
{
request.setTimeStamp(System.currentTimeMillis());
endpoint.setMaxIdleTime(_maxIdleTime);
super.customize(endpoint, request);
}
/* ------------------------------------------------------------------------------- */
@Override
public void persist(EndPoint endpoint) throws IOException
{
AsyncEndPoint aEndp = ((AsyncEndPoint)endpoint);
aEndp.setCheckForIdle(true);
super.persist(endpoint);
}
/* ------------------------------------------------------------ */
public SelectorManager getSelectorManager()
{
return _manager;
}
/* ------------------------------------------------------------ */
public synchronized Object getConnection()
{
return _acceptChannel;
}
/* ------------------------------------------------------------------------------- */
public int getLocalPort()
{
synchronized(this)
{
return _localPort;
}
}
/* ------------------------------------------------------------ */
public void open() throws IOException
{
synchronized(this)
{
if (_acceptChannel == null)
{
// Create a new server socket
_acceptChannel = ServerSocketChannel.open();
// Set to blocking mode
_acceptChannel.configureBlocking(true);
// Bind the server socket to the local host and port
_acceptChannel.socket().setReuseAddress(getReuseAddress());
InetSocketAddress addr = getHost()==null?new InetSocketAddress(getPort()):new InetSocketAddress(getHost(),getPort());
_acceptChannel.socket().bind(addr,getAcceptQueueSize());
_localPort=_acceptChannel.socket().getLocalPort();
if (_localPort<=0)
throw new IOException("Server channel not bound");
addBean(_acceptChannel);
}
}
}
/* ------------------------------------------------------------ */
@Override
public void setMaxIdleTime(int maxIdleTime)
{
_manager.setMaxIdleTime(maxIdleTime);
super.setMaxIdleTime(maxIdleTime);
}
/* ------------------------------------------------------------ */
/**
* @return the lowResourcesConnections
*/
public int getLowResourcesConnections()
{
return _lowResourcesConnections;
}
/* ------------------------------------------------------------ */
/**
* Set the number of connections, which if exceeded places this manager in low resources state.
* This is not an exact measure as the connection count is averaged over the select sets.
* @param lowResourcesConnections the number of connections
* @see #setLowResourcesMaxIdleTime(int)
*/
public void setLowResourcesConnections(int lowResourcesConnections)
{
_lowResourcesConnections=lowResourcesConnections;
}
/* ------------------------------------------------------------ */
/**
* @return the lowResourcesMaxIdleTime
*/
@Override
public int getLowResourcesMaxIdleTime()
{
return _lowResourcesMaxIdleTime;
}
/* ------------------------------------------------------------ */
/**
* Set the period in ms that a connection is allowed to be idle when this there are more
* than {@link #getLowResourcesConnections()} connections. This allows the server to rapidly close idle connections
* in order to gracefully handle high load situations.
* @param lowResourcesMaxIdleTime the period in ms that a connection is allowed to be idle when resources are low.
* @see #setMaxIdleTime(int)
*/
@Override
public void setLowResourcesMaxIdleTime(int lowResourcesMaxIdleTime)
{
_lowResourcesMaxIdleTime=lowResourcesMaxIdleTime;
super.setLowResourcesMaxIdleTime(lowResourcesMaxIdleTime);
}
/* ------------------------------------------------------------ */
/*
* @see org.eclipse.jetty.server.server.AbstractConnector#doStart()
*/
@Override
protected void doStart() throws Exception
{
_manager.setSelectSets(getAcceptors());
_manager.setMaxIdleTime(getMaxIdleTime());
_manager.setLowResourcesConnections(getLowResourcesConnections());
_manager.setLowResourcesMaxIdleTime(getLowResourcesMaxIdleTime());
super.doStart();
}
/* ------------------------------------------------------------ */
protected SelectChannelEndPoint newEndPoint(SocketChannel channel, SelectSet selectSet, SelectionKey key) throws IOException
{
SelectChannelEndPoint endp= new SelectChannelEndPoint(channel,selectSet,key, SelectChannelConnector.this._maxIdleTime);
endp.setConnection(selectSet.getManager().newConnection(channel,endp, key.attachment()));
return endp;
}
/* ------------------------------------------------------------------------------- */
protected void endPointClosed(SelectChannelEndPoint endpoint)
{
connectionClosed(endpoint.getConnection());
}
/* ------------------------------------------------------------------------------- */
protected AsyncConnection newConnection(SocketChannel channel,final AsyncEndPoint endpoint)
{
return new AsyncHttpConnection(SelectChannelConnector.this,endpoint,getServer());
}
/* ------------------------------------------------------------ */
/* ------------------------------------------------------------ */
/* ------------------------------------------------------------ */
private final class ConnectorSelectorManager extends SelectorManager
{
@Override
public boolean dispatch(Runnable task)
{
ThreadPool pool=getThreadPool();
if (pool==null)
pool=getServer().getThreadPool();
return pool.dispatch(task);
}
@Override
protected void endPointClosed(final SelectChannelEndPoint endpoint)
{
SelectChannelConnector.this.endPointClosed(endpoint);
}
@Override
protected void endPointOpened(SelectChannelEndPoint endpoint)
{
// TODO handle max connections and low resources
connectionOpened(endpoint.getConnection());
}
@Override
protected void endPointUpgraded(ConnectedEndPoint endpoint, Connection oldConnection)
{
connectionUpgraded(oldConnection,endpoint.getConnection());
}
@Override
public AsyncConnection newConnection(SocketChannel channel,AsyncEndPoint endpoint, Object attachment)
{
return SelectChannelConnector.this.newConnection(channel,endpoint);
}
@Override
protected SelectChannelEndPoint newEndPoint(SocketChannel channel, SelectSet selectSet, SelectionKey sKey) throws IOException
{
return SelectChannelConnector.this.newEndPoint(channel,selectSet,sKey);
}
}
}