org.objectweb.dream.pump.AbstractPumpSynchronized Maven / Gradle / Ivy
/**
* Dream
* Copyright (C) 2003-2004 INRIA Rhone-Alpes.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Contact : [email protected]
*
* Initial developer(s): Vivien Quema
* Contributor(s): Romain Lenglet
*/
package org.objectweb.dream.pump;
import org.objectweb.dream.Pull;
import org.objectweb.dream.PullException;
import org.objectweb.dream.Push;
import org.objectweb.dream.PushException;
import org.objectweb.dream.control.activity.manager.TaskManager;
import org.objectweb.dream.control.activity.task.AbstractTask;
import org.objectweb.dream.control.activity.task.Task;
import org.objectweb.dream.message.Message;
import org.objectweb.dream.message.MessageManagerType;
import org.objectweb.dream.synchro.MutexItf;
import org.objectweb.dream.util.LoggerUtil;
import org.objectweb.fractal.api.Component;
import org.objectweb.fractal.api.control.IllegalLifeCycleException;
import org.objectweb.fractal.fraclet.annotation.annotations.Attribute;
import org.objectweb.fractal.fraclet.annotation.annotations.Service;
import org.objectweb.dream.dreamannotation.DreamComponent;
import org.objectweb.dream.dreamannotation.DreamLifeCycle;
import org.objectweb.dream.dreamannotation.DreamMonolog;
import org.objectweb.dream.dreamannotation.util.DreamLifeCycleType;
import org.objectweb.fractal.fraclet.annotation.annotations.Requires;
import org.objectweb.fractal.fraclet.annotation.annotations.type.Contingency;
import org.objectweb.util.monolog.api.BasicLevel;
import org.objectweb.util.monolog.api.Logger;
/**
* Abstract implementation of a synchronized Pull/Push pump. This component has
* an optional {@link org.objectweb.dream.synchro.MutexItf} client interface
* that it uses to synchronize the execution of its run method with other
* components.
*/
@DreamComponent(controllerDesc = "activeDreamPrimitive")
public abstract class AbstractPumpSynchronized
{
// ---------------------------------------------------------------------------
// Client interfaces
// ---------------------------------------------------------------------------
@Requires(name = "out-push")
protected Push outPushItf;
@Requires(name = "in-pull")
protected Pull inPullItf;
@Requires(name = MutexItf.ITF_NAME, contingency = Contingency.OPTIONAL)
protected MutexItf mutexItf;
@Requires(name = "message-manager")
protected MessageManagerType messageManagerItf;
@Requires(name = "task-manager")
protected TaskManager taskManagerItf;
// --------------------------------------------------------------------------
// Services interfaces
// --------------------------------------------------------------------------
/**
* Component reference
*/
@Service
Component weaveableC;
/**
* Logger of the component
*/
@DreamMonolog()
protected Logger logger;
// ---------------------------------------------------------------------------
// Attributes
// ---------------------------------------------------------------------------
/**
* the PushNullPolicy indicates whether "null" messages that
* are pulled must be pushed or not. Its default value is false.
*/
@Attribute(argument = "pushNullPolicy")
protected boolean pushNullPolicy = false;
/**
* the StopOnPushExceptionPolicy indicates whether the task
* must be stopped when a {@link org.objectweb.dream.PushException} occurs.
* Its default value is true.
*/
@Attribute(argument = "stopOnPushExceptionPolicy")
protected boolean stopOnPushExceptionPolicy = true;
/**
* the StopOnPullExceptionPolicy indicates whether the task
* must be stopped when a {@link org.objectweb.dream.PullException} occurs.
* Its default value is true.
*/
@Attribute(argument = "stopOnPullExceptionPolicy")
protected boolean stopOnPullExceptionPolicy = true;
// ---------------------------------------------------------------------------
// Fields
// ---------------------------------------------------------------------------
protected AbstractTask pumpTask = new PumpTask();
/**
* True when the stopFc() method has been called on the component interface.
*/
protected boolean isComponentStopping = false;
// ---------------------------------------------------------------------------
// Implementation of PumpTask class
// ---------------------------------------------------------------------------
class PumpTask extends AbstractTask
{
/**
* Default constructor
*/
public PumpTask()
{
super("PumpTask");
}
/**
* @see org.objectweb.dream.control.activity.task.Task#execute(Object)
*/
public Object execute(Object hints) throws InterruptedException
{
LoggerUtil.start(logger);
if (mutexItf != null)
{
mutexItf.lock();
}
Message msg = null;
try
{
msg = inPullItf.pull();
if (msg != null || pushNullPolicy)
{
outPushItf.push(msg);
}
}
catch (PullException e)
{
return handlePullException(e);
}
catch (PushException e)
{
return handlePushException(msg, e);
}
finally
{
if (mutexItf != null)
{
mutexItf.unlock();
}
}
return EXECUTE_AGAIN;
}
}
// ---------------------------------------------------------------------------
// Utility methods.
// ---------------------------------------------------------------------------
/**
* Handles a {@link PushException} occurring when the activity tries to push a
* message. This implementation simply deletes the message using message
* manger.
*
* @param message the pushed message
* @param exception the exception thrown during the push call.
*/
protected Object handlePushException(Message message, PushException exception)
{
messageManagerItf.deleteMessage(message);
if (stopOnPushExceptionPolicy)
{
if (logger.isLoggable(BasicLevel.WARN))
{
logger.log(BasicLevel.WARN,
"Push exception occurred, stop executing the task", exception);
}
return Task.STOP_EXECUTING;
}
if (logger.isLoggable(BasicLevel.WARN))
{
logger.log(BasicLevel.WARN,
"Push exception occurred, continue executing the task", exception);
}
return Task.EXECUTE_AGAIN;
}
/**
* Handles a {@link PullException} occurring when the activity tries to pull a
* message.
*
* @param exception the exception thrown during the pull call.
*/
protected Object handlePullException(PullException exception)
{
LoggerUtil.start(logger);
// test if the component is stopping
if (isComponentStopping)
{
// The exception has been generated by the activity manager
// So this exception is not logged.
// The task is simply stopped
return AbstractTask.STOP_EXECUTING;
}
if (stopOnPullExceptionPolicy)
{
if (logger.isLoggable(BasicLevel.WARN))
{
logger.log(BasicLevel.WARN,
"Pull exception occurred, stop executing the task", exception);
}
LoggerUtil.returnAfter(logger);
return AbstractTask.STOP_EXECUTING;
}
if (logger.isLoggable(BasicLevel.WARN))
{
logger.log(BasicLevel.WARN,
"Pull exception occurred, continue executing the task", exception);
}
LoggerUtil.returnAfter(logger);
return AbstractTask.EXECUTE_AGAIN;
}
/**
* @see org.objectweb.dream.AbstractComponent#beforeFirstStart(Component)
*/
@DreamLifeCycle(on = DreamLifeCycleType.PREPARE_TO_STOP)
protected void prepareStopFcHandler() throws IllegalLifeCycleException
{
LoggerUtil.start(logger);
isComponentStopping = true;
LoggerUtil.end(logger);
}
}
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