org/objectweb/proactive/calcium/Interpreter.java

/* 
 * ################################################################
 * 
 * ProActive: The Java(TM) library for Parallel, Distributed, 
 *            Concurrent computing with Security and Mobility
 * 
 * Copyright (C) 1997-2007 INRIA/University of Nice-Sophia Antipolis
 * Contact: proactive@objectweb.org
 * 
 * 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 2.1 of the License, or 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
 *  
 *  Initial developer(s):               The ProActive Team
 *                        http://www.inria.fr/oasis/ProActive/contacts.html
 *  Contributor(s): 
 * 
 * ################################################################
 */ 
package org.objectweb.proactive.calcium;

import java.io.Serializable;

import org.apache.log4j.Logger;
import org.objectweb.proactive.calcium.exceptions.PanicException;
import org.objectweb.proactive.calcium.interfaces.Instruction;
import org.objectweb.proactive.calcium.statistics.Timer;
import org.objectweb.proactive.core.util.log.Loggers;
import org.objectweb.proactive.core.util.log.ProActiveLogger;

public class Interpreter implements Serializable {
        static Logger logger = ProActiveLogger.getLogger(Loggers.SKELETONS_STRUCTURE);
        
        public Interpreter(){
        }
        
        public <T> Task<T> interpret(Task<T> task){
                
                Timer timer=new Timer(true);
                while(task.hasInstruction()){
                        if(logger.isDebugEnabled()){
                                logger.debug("--Stack Top-- Task="+task.getId()+" "+task.getObject());
                                String tmp="";
                                for(Instruction c:task.getStack()) tmp=c+"\n"+tmp;
                                tmp=tmp.trim();
                                logger.debug(tmp);
                        }

                        //Take the top instruction
                        Instruction<T> inst = task.popInstruction();

                        //Compute the instruction
                        int oldId=task.getId();
                        
                        try {
                                task=inst.compute(task);
                        } catch (Exception e) {                 //If an exception happend, we report the exception in the task
                                task.pushInstruction(inst); //we put back the instruction that generated the exception
                                task.setException(e);           //then we add the exception to the task
                                return task;
                        }

                        if(oldId!=task.getId()){
                                String msg = "Panic error, task id changed while interpreting! "+oldId+"->"+task.getId();
                                task.pushInstruction(inst);
                                task.setException(new PanicException(msg));
                                logger.error(msg);
                                return task;
                        }
                        
                        //If child tasks are present, that's all folks (for now)
                        if(task.hasReadyChildTask()){
                                timer.stop();
                                task.getStats().addComputationTime(timer.getTime());
                                return task;
                        }
                }//while

                //The task is finished
                timer.stop();
                task.getStats().addComputationTime(timer.getTime());
                return task;
        }
}

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