/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can obtain
* a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
* or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
* Sun designates this particular file as subject to the "Classpath" exception
* as provided by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the License
* Header, with the fields enclosed by brackets [] replaced by your own
* identifying information: "Portions Copyrighted [year]
* [name of copyright owner]"
*
* Contributor(s):
*
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.sun.enterprise.web.connector.grizzly.async;
import com.sun.enterprise.web.connector.grizzly.AsyncExecutor;
import com.sun.enterprise.web.connector.grizzly.AsyncFilter;
import com.sun.enterprise.web.connector.grizzly.AsyncHandler;
import com.sun.enterprise.web.connector.grizzly.AsyncTask;
import com.sun.enterprise.web.connector.grizzly.ProcessorTask;
import com.sun.enterprise.web.connector.grizzly.Task;
import java.util.ArrayList;
import java.util.concurrent.ConcurrentLinkedQueue;
/**
* Default implementation of <code>AsyncHandler</code>. This class handle
* the aysnchronous execution of a <code>ProcessorTask</code>. The request
* processing is executed by doing:
*
* (1) Wrap the <code>ProcessorTask</code> using an instance of
* <code>AsyncTask</code>
* (2) Execute the <code>AsyncTask</code> using the wrapped
* <code>ProcessorTask</code> <code>Pipeline</code>
* (3) If the <code>AsyncTask</code> has been interrupted but ready
* to be removed from the interrupted queue, remove it and execute the
* remaining operations.
*
* @author Jeanfrancois Arcand
*/
public class DefaultAsyncHandler implements AsyncHandler{
/**
* Cache instance of <code>AsyncTask</code>
*/
private ConcurrentLinkedQueue<AsyncTask>
asyncProcessors = new ConcurrentLinkedQueue<AsyncTask>();
/**
* A queue used to cache interrupted <code>AsyncTask</code>.
*/
private ConcurrentLinkedQueue<AsyncTask>
interrruptedQueue = new ConcurrentLinkedQueue<AsyncTask>();
/**
* The <code>AsyncFilter</code> to execute asynchronous operations on
* a <code>ProcessorTask</code>.
*/
private ArrayList<AsyncFilter> asyncFilters =
new ArrayList<AsyncFilter>();
/**
* The <code>AsyncExecutor</code> class name to use.
*/
private String asyncExecutorClassName
= "com.sun.enterprise.web.connector.grizzly.async.DefaultAsyncExecutor";
// ------------------------------------------------- Constructor --------//
public DefaultAsyncHandler() {
}
/**
* Create an instance of <code>AsyncTask</code>
*/
private AsyncTask newAsyncProcessorTask(){
AsyncTask asyncTask = new AsyncProcessorTask();
asyncTask.setAsyncExecutor(newAsyncExecutor(asyncTask));
return asyncTask;
}
/**
* Create an instance of <code>DefaultAsyncExecutor</code>
*/
private AsyncExecutor newAsyncExecutor(AsyncTask asyncTask){
Class className = null;
AsyncExecutor asyncExecutor = null;
try{
className = Class.forName(asyncExecutorClassName);
asyncExecutor = (AsyncExecutor)className.newInstance();
} catch (ClassNotFoundException ex){
throw new RuntimeException(ex);
} catch (InstantiationException ex){
throw new RuntimeException(ex);
} catch (IllegalAccessException ex){
throw new RuntimeException(ex);
}
if ( asyncExecutor != null ){
asyncExecutor.setAsyncTask(asyncTask);
asyncExecutor.setAsyncHandler(this);
for (AsyncFilter l : asyncFilters){
asyncExecutor.addAsyncFilter(l);
}
}
return asyncExecutor;
}
/**
* Return an instance of <code>AsyncTask</code>, which is
* configured and ready to be executed.
*/
private AsyncTask getAsyncProcessorTask(){
AsyncTask asyncTask = asyncProcessors.poll();
if ( asyncTask == null) {
asyncTask = newAsyncProcessorTask();
} else {
asyncTask.recycle();
}
return asyncTask;
}
// ---------------------------------------------------- Interface -------//
/**
* Handle an instance of a <code>Task</code>. This method is invoked
* first by a <code>ProcessorTask</code>, which delegate its execution to
* this handler. Second, this method is invoked once a
* <code>ProcessorTask</code> needs to be removed from the interrupted queue.
*/
public void handle(Task task){
AsyncTask apt = null;
if (task.getType() == Task.PROCESSOR_TASK) {
apt = getAsyncProcessorTask();
apt.setProcessorTask((ProcessorTask)task);
apt.setSelectorThread(task.getSelectorThread());
}
boolean wasInterrupted = interrruptedQueue.remove(task);
if ( !wasInterrupted && apt == null) {
String errorMsg = "";
if ( task.getSelectionKey() != null ) {
errorMsg = "Connection " + task.getSelectionKey().channel()
+ " wasn't interrupted";
}
throw new IllegalStateException(errorMsg);
} else if ( apt == null ){
apt = (AsyncTask)task;
}
apt.execute();
}
/**
* Return th <code>Task</code> to the pool
*/
public void returnTask(AsyncTask asyncTask){
asyncProcessors.offer(asyncTask);
}
/**
* Add a <code>Task</code> to the interrupted queue.
*/
public void addToInterruptedQueue(AsyncTask task){
interrruptedQueue.offer(task);
}
/**
* Remove the <code>Task</code> from the interrupted queue.
*/
public void removeFromInterruptedQueue(AsyncTask task){
interrruptedQueue.remove(task);
}
/**
* Set the <code>AsyncExecutor</code> used by this object.
*/
public void setAsyncExecutorClassName(String asyncExecutorClassName){
this.asyncExecutorClassName = asyncExecutorClassName;
}
/**
* Get the code>AsyncExecutor</code> used by this object.
*/
public String getAsyncExecutorClassName(){
return asyncExecutorClassName;
}
/**
* Add an <code>AsyncFilter</code>
*/
public void addAsyncFilter(AsyncFilter asyncFilter) {
asyncFilters.add(asyncFilter);
}
/**
* Remove an <code>AsyncFilter</code>
*/
public boolean removeAsyncFilter(AsyncFilter asyncFilter) {
return asyncFilters.remove(asyncFilter);
}
}
|
