/*
* Copyright 2005 Joe Walker
*
* 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.directwebremoting.contrib;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.directwebremoting.extend.Call;
import org.directwebremoting.extend.Calls;
import org.directwebremoting.extend.Replies;
import org.directwebremoting.extend.Reply;
import org.directwebremoting.impl.DefaultRemoter;
/**
* This implementation is not officially supported, and may be removed
* at some point in the future.
* Remoter implementation executing in parallel a group of remote calls.
* @author <a href="mailto:chussenet@yahoo.com">Claude Hussenet</a>
*/
public class ParallelDefaultRemoter extends DefaultRemoter
{
/**
* Initialize thread pool with :
* Core pool size : 10;
* Maximum pool size = 100;
* Keep alive time = 5000(ms);
* Timeout = 10000(ms);
*/
public ParallelDefaultRemoter()
{
executorService = (ThreadPoolExecutor) Executors.newCachedThreadPool();
executorService.setCorePoolSize(corePoolsize);
executorService.setMaximumPoolSize(maximumPoolsize);
executorService.setKeepAliveTime(keepAliveTime, TimeUnit.MILLISECONDS);
}
/**
* Sets the maximum time to wait in (ms)
* @param timeout Time in (ms)
*/
public void setParallelDefaultRemoterTimeout(long timeout)
{
this.timeout = timeout;
}
/**
* Sets the core number of threads.
* @param corePoolsize How many threads do we use
*/
public void setParallelDefaultRemoterCorePoolsize(int corePoolsize)
{
this.corePoolsize = corePoolsize;
executorService.setCorePoolSize(corePoolsize);
}
/**
* Sets the maximum allowed number of threads.
* @param maximumPoolsize Maximum of threads
*/
public void setParallelDefaultRemoterMaximumPoolsize(int maximumPoolsize)
{
this.maximumPoolsize = maximumPoolsize;
executorService.setMaximumPoolSize(maximumPoolsize);
}
/**
* Sets the time limit in (ms) for which threads may remain idle before being
* terminated.
* @param keepAliveTime Time in (ms)
*/
public void setParallelDefaultRemoterKeepAliveTime(long keepAliveTime)
{
this.keepAliveTime = keepAliveTime;
executorService.setKeepAliveTime(keepAliveTime, TimeUnit.MILLISECONDS);
}
/**
* Execute a set of remote calls in parallel and generate set of reply data
* for later conversion to whatever wire protocol we are using today.
* @param calls The set of calls to execute in parallel
* @return A set of reply data objects
*/
@Override
public Replies execute(Calls calls)
{
Replies replies = new Replies(calls);
Future<?>[] future = new Future<?>[calls.getCallCount()];
if (calls.getCallCount() == 1)
{
return super.execute(calls);
}
else
{
for (int callNum = 0; callNum < calls.getCallCount(); callNum++)
{
Call call = calls.getCall(callNum);
future[callNum] = executorService.submit(new CallCallable(call));
}
for (int callNum = 0; callNum < calls.getCallCount(); callNum++)
{
try
{
Reply reply = (Reply) future[callNum].get(timeout, TimeUnit.MILLISECONDS);
replies.addReply(reply);
}
catch (InterruptedException ex)
{
log.warn("Method execution failed: ", ex);
replies.addReply(new Reply(calls.getCall(callNum).getCallId(), null, ex));
}
catch (ExecutionException ex)
{
log.warn("Method execution failed: ", ex);
replies.addReply(new Reply(calls.getCall(callNum).getCallId(), null, ex));
}
catch (TimeoutException ex)
{
log.warn("Method execution failed: ", ex);
replies.addReply(new Reply(calls.getCall(callNum).getCallId(), null, ex));
}
}
return replies;
}
}
/**
* An implementation of Callable that uses a DWR Call object.
*/
private class CallCallable implements Callable<Reply>
{
/**
* @param call The call to execute
*/
public CallCallable(Call call)
{
this.call = call;
}
public Reply call()
{
return execute(call);
}
private final Call call;
}
private static final Log log = LogFactory.getLog(ParallelDefaultRemoter.class);
private int corePoolsize = 10;
private int maximumPoolsize = 100;
private long keepAliveTime = 5000;
private long timeout = 10000;
private final ThreadPoolExecutor executorService;
}