org.eclipse.jetty.server.HttpChannelState Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of a-jetty-base Show documentation
Show all versions of a-jetty-base Show documentation
A-Jetty Base can run on Android Java as well as on standard Java 7+ and it can run precompiled JSP/JSTL.
//
// ========================================================================
// Copyright (c) 1995-2016 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;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import javax.servlet.AsyncListener;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletResponse;
import org.eclipse.jetty.server.handler.ContextHandler;
import org.eclipse.jetty.server.handler.ContextHandler.Context;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.util.thread.Scheduler;
/**
* Implementation of AsyncContext interface that holds the state of request-response cycle.
*/
public class HttpChannelState
{
private static final Logger LOG = Log.getLogger(HttpChannelState.class);
private final static long DEFAULT_TIMEOUT=Long.getLong("org.eclipse.jetty.server.HttpChannelState.DEFAULT_TIMEOUT",30000L);
/** The dispatched state of the HttpChannel, used to control the overall livecycle
*/
public enum State
{
IDLE, // Idle request
DISPATCHED, // Request dispatched to filter/servlet
ASYNC_WAIT, // Suspended and parked
ASYNC_WOKEN, // A thread has been dispatch to handle from ASYNCWAIT
ASYNC_IO, // Has been dispatched for async IO
COMPLETING, // Request is completable
COMPLETED, // Request is complete
UPGRADED // Request upgraded the connection
}
/**
* The actions to take as the channel moves from state to state.
*/
public enum Action
{
REQUEST_DISPATCH, // handle a normal request dispatch
ASYNC_DISPATCH, // handle an async request dispatch
ASYNC_EXPIRED, // handle an async timeout
WRITE_CALLBACK, // handle an IO write callback
READ_CALLBACK, // handle an IO read callback
WAIT, // Wait for further events
COMPLETE // Complete the channel
}
/**
* The state of the servlet async API. This can lead or follow the
* channel dispatch state and also includes reasons such as expired,
* dispatched or completed.
*/
public enum Async
{
STARTED,
DISPATCH,
COMPLETE,
EXPIRING,
EXPIRED
}
private final boolean DEBUG=LOG.isDebugEnabled();
private final HttpChannel _channel;
private List _asyncListeners;
private State _state;
private Async _async;
private boolean _initial;
private boolean _asyncRead;
private boolean _asyncWrite;
private long _timeoutMs=DEFAULT_TIMEOUT;
private AsyncContextEvent _event;
protected HttpChannelState(HttpChannel channel)
{
_channel=channel;
_state=State.IDLE;
_async=null;
_initial=true;
}
public State getState()
{
synchronized(this)
{
return _state;
}
}
public void addListener(AsyncListener listener)
{
synchronized(this)
{
if (_asyncListeners==null)
_asyncListeners=new ArrayList<>();
_asyncListeners.add(listener);
}
}
public void setTimeout(long ms)
{
synchronized(this)
{
_timeoutMs=ms;
}
}
public long getTimeout()
{
synchronized(this)
{
return _timeoutMs;
}
}
public AsyncContextEvent getAsyncContextEvent()
{
synchronized(this)
{
return _event;
}
}
@Override
public String toString()
{
synchronized (this)
{
return String.format("%s@%x{s=%s i=%b a=%s}",getClass().getSimpleName(),hashCode(),_state,_initial,_async);
}
}
public String getStatusString()
{
synchronized (this)
{
return String.format("s=%s i=%b a=%s",_state,_initial,_async);
}
}
/**
* @return Next handling of the request should proceed
*/
protected Action handling()
{
synchronized (this)
{
if(DEBUG)
LOG.debug("{} handling {}",this,_state);
switch(_state)
{
case IDLE:
_initial=true;
_state=State.DISPATCHED;
return Action.REQUEST_DISPATCH;
case COMPLETING:
return Action.COMPLETE;
case COMPLETED:
return Action.WAIT;
case ASYNC_WOKEN:
if (_asyncRead)
{
_state=State.ASYNC_IO;
_asyncRead=false;
return Action.READ_CALLBACK;
}
if (_asyncWrite)
{
_state=State.ASYNC_IO;
_asyncWrite=false;
return Action.WRITE_CALLBACK;
}
if (_async!=null)
{
Async async=_async;
switch(async)
{
case COMPLETE:
_state=State.COMPLETING;
return Action.COMPLETE;
case DISPATCH:
_state=State.DISPATCHED;
_async=null;
return Action.ASYNC_DISPATCH;
case EXPIRING:
break;
case EXPIRED:
_state=State.DISPATCHED;
_async=null;
return Action.ASYNC_EXPIRED;
case STARTED:
// TODO
if (DEBUG)
LOG.debug("TODO Fix this double dispatch",new IllegalStateException(this
.getStatusString()));
return Action.WAIT;
}
}
return Action.WAIT;
default:
throw new IllegalStateException(this.getStatusString());
}
}
}
public void startAsync(AsyncContextEvent event)
{
final List lastAsyncListeners;
synchronized (this)
{
if (_state!=State.DISPATCHED || _async!=null)
throw new IllegalStateException(this.getStatusString());
_async=Async.STARTED;
_event=event;
lastAsyncListeners=_asyncListeners;
_asyncListeners=null;
}
if (lastAsyncListeners!=null)
{
for (AsyncListener listener : lastAsyncListeners)
{
try
{
listener.onStartAsync(event);
}
catch(Exception e)
{
LOG.warn(e);
}
}
}
}
protected void error(Throwable th)
{
synchronized (this)
{
if (_event!=null)
_event.setThrowable(th);
}
}
/**
* Signal that the HttpConnection has finished handling the request.
* For blocking connectors, this call may block if the request has
* been suspended (startAsync called).
* @return next actions
* be handled again (eg because of a resume that happened before unhandle was called)
*/
protected Action unhandle()
{
synchronized (this)
{
if(DEBUG)
LOG.debug("{} unhandle {}",this,_state);
switch(_state)
{
case DISPATCHED:
case ASYNC_IO:
break;
default:
throw new IllegalStateException(this.getStatusString());
}
if (_asyncRead)
{
_state=State.ASYNC_IO;
_asyncRead=false;
return Action.READ_CALLBACK;
}
if (_asyncWrite)
{
_asyncWrite=false;
_state=State.ASYNC_IO;
return Action.WRITE_CALLBACK;
}
if (_async!=null)
{
_initial=false;
switch(_async)
{
case COMPLETE:
_state=State.COMPLETING;
_async=null;
return Action.COMPLETE;
case DISPATCH:
_state=State.DISPATCHED;
_async=null;
return Action.ASYNC_DISPATCH;
case EXPIRED:
_state=State.DISPATCHED;
_async=null;
return Action.ASYNC_EXPIRED;
case EXPIRING:
case STARTED:
scheduleTimeout();
_state=State.ASYNC_WAIT;
return Action.WAIT;
}
}
_state=State.COMPLETING;
return Action.COMPLETE;
}
}
public void dispatch(ServletContext context, String path)
{
boolean dispatch;
synchronized (this)
{
if (_async!=Async.STARTED && _async!=Async.EXPIRING)
throw new IllegalStateException("AsyncContext#dispath "+this.getStatusString());
_async=Async.DISPATCH;
if (context!=null)
_event.setDispatchContext(context);
if (path!=null)
_event.setDispatchPath(path);
switch(_state)
{
case DISPATCHED:
case ASYNC_IO:
dispatch=false;
break;
case ASYNC_WAIT:
_state=State.ASYNC_WOKEN;
dispatch=true;
break;
case ASYNC_WOKEN:
dispatch=false;
break;
default:
LOG.warn("async dispatched when complete {}",this);
dispatch=false;
break;
}
}
cancelTimeout();
if (dispatch)
scheduleDispatch();
}
protected void expired()
{
final List aListeners;
AsyncContextEvent event;
synchronized (this)
{
if (_async!=Async.STARTED)
return;
_async=Async.EXPIRING;
event=_event;
aListeners=_asyncListeners;
}
if (aListeners!=null)
{
for (AsyncListener listener : aListeners)
{
try
{
listener.onTimeout(event);
}
catch(Exception e)
{
LOG.debug(e);
event.setThrowable(e);
_channel.getRequest().setAttribute(RequestDispatcher.ERROR_EXCEPTION,e);
break;
}
}
}
boolean dispatch=false;
synchronized (this)
{
if (_async==Async.EXPIRING)
{
_async=Async.EXPIRED;
if (_state==State.ASYNC_WAIT)
{
_state=State.ASYNC_WOKEN;
dispatch=true;
}
}
}
if (dispatch)
scheduleDispatch();
}
public void complete()
{
// just like resume, except don't set _dispatched=true;
boolean handle=false;
synchronized (this)
{
if (_async!=Async.STARTED && _async!=Async.EXPIRING)
throw new IllegalStateException(this.getStatusString());
_async=Async.COMPLETE;
if (_state==State.ASYNC_WAIT)
{
handle=true;
_state=State.ASYNC_WOKEN;
}
}
cancelTimeout();
if (handle)
{
ContextHandler handler=getContextHandler();
if (handler!=null)
handler.handle(_channel);
else
_channel.handle();
}
}
public void errorComplete()
{
synchronized (this)
{
_async=Async.COMPLETE;
_event.setDispatchContext(null);
_event.setDispatchPath(null);
}
cancelTimeout();
}
protected void completed()
{
final List aListeners;
final AsyncContextEvent event;
synchronized (this)
{
switch(_state)
{
case COMPLETING:
_state=State.COMPLETED;
aListeners=_asyncListeners;
event=_event;
break;
default:
throw new IllegalStateException(this.getStatusString());
}
}
if (event!=null)
{
if (aListeners!=null)
{
if (event.getThrowable()!=null)
{
event.getSuppliedRequest().setAttribute(RequestDispatcher.ERROR_EXCEPTION,event.getThrowable());
event.getSuppliedRequest().setAttribute(RequestDispatcher.ERROR_MESSAGE,event.getThrowable().getMessage());
}
for (AsyncListener listener : aListeners)
{
try
{
if (event.getThrowable()!=null)
listener.onError(event);
else
listener.onComplete(event);
}
catch(Exception e)
{
LOG.warn(e);
}
}
}
event.completed();
}
}
protected void recycle()
{
synchronized (this)
{
switch(_state)
{
case DISPATCHED:
case ASYNC_IO:
throw new IllegalStateException(getStatusString());
case UPGRADED:
return;
default:
break;
}
_asyncListeners=null;
_state=State.IDLE;
_async=null;
_initial=true;
_asyncRead=false;
_asyncWrite=false;
_timeoutMs=DEFAULT_TIMEOUT;
cancelTimeout();
_event=null;
}
}
public void upgrade()
{
synchronized (this)
{
switch(_state)
{
case IDLE:
case COMPLETED:
break;
default:
throw new IllegalStateException(getStatusString());
}
_asyncListeners=null;
_state=State.UPGRADED;
_async=null;
_initial=true;
_asyncRead=false;
_asyncWrite=false;
_timeoutMs=DEFAULT_TIMEOUT;
cancelTimeout();
_event=null;
}
}
protected void scheduleDispatch()
{
_channel.execute(_channel);
}
protected void scheduleTimeout()
{
Scheduler scheduler = _channel.getScheduler();
if (scheduler!=null && _timeoutMs>0)
_event.setTimeoutTask(scheduler.schedule(_event,_timeoutMs,TimeUnit.MILLISECONDS));
}
protected void cancelTimeout()
{
final AsyncContextEvent event;
synchronized (this)
{
event=_event;
}
if (event!=null)
event.cancelTimeoutTask();
}
public boolean isExpired()
{
synchronized (this)
{
return _async==Async.EXPIRED;
}
}
public boolean isInitial()
{
synchronized(this)
{
return _initial;
}
}
public boolean isSuspended()
{
synchronized(this)
{
return _state==State.ASYNC_WAIT || _state==State.DISPATCHED && _async==Async.STARTED;
}
}
boolean isCompleting()
{
synchronized (this)
{
return _state==State.COMPLETING;
}
}
boolean isCompleted()
{
synchronized (this)
{
return _state == State.COMPLETED;
}
}
public boolean isAsyncStarted()
{
synchronized (this)
{
if (_state==State.DISPATCHED)
return _async!=null;
return _async==Async.STARTED || _async==Async.EXPIRING;
}
}
public boolean isAsync()
{
synchronized (this)
{
return !_initial || _async!=null;
}
}
public Request getBaseRequest()
{
return _channel.getRequest();
}
public HttpChannel getHttpChannel()
{
return _channel;
}
public ContextHandler getContextHandler()
{
final AsyncContextEvent event;
synchronized (this)
{
event=_event;
}
if (event!=null)
{
Context context=((Context)event.getServletContext());
if (context!=null)
return context.getContextHandler();
}
return null;
}
public ServletResponse getServletResponse()
{
final AsyncContextEvent event;
synchronized (this)
{
event=_event;
}
if (event!=null && event.getSuppliedResponse()!=null)
return event.getSuppliedResponse();
return _channel.getResponse();
}
public Object getAttribute(String name)
{
return _channel.getRequest().getAttribute(name);
}
public void removeAttribute(String name)
{
_channel.getRequest().removeAttribute(name);
}
public void setAttribute(String name, Object attribute)
{
_channel.getRequest().setAttribute(name,attribute);
}
public void onReadPossible()
{
boolean handle=false;
synchronized (this)
{
_asyncRead=true;
if (_state==State.ASYNC_WAIT)
{
_state=State.ASYNC_WOKEN;
handle=true;
}
}
if (handle)
_channel.execute(_channel);
}
public void onWritePossible()
{
boolean handle=false;
synchronized (this)
{
_asyncWrite=true;
if (_state==State.ASYNC_WAIT)
{
_state=State.ASYNC_WOKEN;
handle=true;
}
}
if (handle)
_channel.execute(_channel);
}
}