MOA 12.03
Real Time Analytics for Data Streams
TaskThread.java
Go to the documentation of this file.
00001 /*
00002  *    TaskThread.java
00003  *    Copyright (C) 2007 University of Waikato, Hamilton, New Zealand
00004  *    @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
00005  *
00006  *    This program is free software; you can redistribute it and/or modify
00007  *    it under the terms of the GNU General Public License as published by
00008  *    the Free Software Foundation; either version 3 of the License, or
00009  *    (at your option) any later version.
00010  *
00011  *    This program is distributed in the hope that it will be useful,
00012  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  *    GNU General Public License for more details.
00015  *
00016  *    You should have received a copy of the GNU General Public License
00017  *    along with this program. If not, see <http://www.gnu.org/licenses/>.
00018  *    
00019  */
00020 package moa.tasks;
00021 
00022 import java.util.concurrent.CopyOnWriteArraySet;
00023 
00024 import moa.core.ObjectRepository;
00025 import moa.core.TimingUtils;
00026 
00033 public class TaskThread extends Thread {
00034 
00035     public static enum Status {
00036 
00037         NOT_STARTED, RUNNING, PAUSED, CANCELLING, CANCELLED, COMPLETED, FAILED
00038     }
00039 
00040     protected Task runningTask;
00041 
00042     protected volatile Status currentStatus;
00043 
00044     protected TaskMonitor taskMonitor;
00045 
00046     protected ObjectRepository repository;
00047 
00048     protected Object finalResult;
00049 
00050     protected long taskStartTime;
00051 
00052     protected long taskEndTime;
00053 
00054     protected double latestPreviewGrabTime = 0.0;
00055 
00056     CopyOnWriteArraySet<TaskCompletionListener> completionListeners = new CopyOnWriteArraySet<TaskCompletionListener>();
00057 
00058     public TaskThread(Task toRun) {
00059         this(toRun, null);
00060     }
00061 
00062     public TaskThread(Task toRun, ObjectRepository repository) {
00063         this.runningTask = toRun;
00064         this.repository = repository;
00065         this.currentStatus = Status.NOT_STARTED;
00066         this.taskMonitor = new StandardTaskMonitor();
00067         this.taskMonitor.setCurrentActivityDescription("Running task " + toRun);
00068     }
00069 
00070     @Override
00071     public void run() {
00072         TimingUtils.enablePreciseTiming();
00073         this.taskStartTime = TimingUtils.getNanoCPUTimeOfThread(getId());
00074         try {
00075             this.currentStatus = Status.RUNNING;
00076             this.finalResult = this.runningTask.doTask(this.taskMonitor,
00077                     this.repository);
00078             this.currentStatus = this.taskMonitor.isCancelled() ? Status.CANCELLED
00079                     : Status.COMPLETED;
00080         } catch (Throwable ex) {
00081             this.currentStatus = Status.FAILED;
00082             this.finalResult = new FailedTaskReport(ex);
00083         }
00084         this.taskEndTime = TimingUtils.getNanoCPUTimeOfThread(getId());
00085         fireTaskCompleted();
00086         this.taskMonitor.setLatestResultPreview(null); // free preview memory
00087     }
00088 
00089     public synchronized void pauseTask() {
00090         if (this.currentStatus == Status.RUNNING) {
00091             this.taskMonitor.requestPause();
00092             this.currentStatus = Status.PAUSED;
00093         }
00094     }
00095 
00096     public synchronized void resumeTask() {
00097         if (this.currentStatus == Status.PAUSED) {
00098             this.taskMonitor.requestResume();
00099             this.currentStatus = Status.RUNNING;
00100         }
00101     }
00102 
00103     public synchronized void cancelTask() {
00104         if ((this.currentStatus == Status.RUNNING)
00105                 || (this.currentStatus == Status.PAUSED)) {
00106             this.taskMonitor.requestCancel();
00107             this.currentStatus = Status.CANCELLING;
00108         }
00109     }
00110 
00111     public double getCPUSecondsElapsed() {
00112         double secondsElapsed = 0.0;
00113         if (this.currentStatus == Status.NOT_STARTED) {
00114             secondsElapsed = 0.0;
00115         } else if (isComplete()) {
00116             secondsElapsed = TimingUtils.nanoTimeToSeconds(this.taskEndTime
00117                     - this.taskStartTime);
00118         } else {
00119             secondsElapsed = TimingUtils.nanoTimeToSeconds(TimingUtils.getNanoCPUTimeOfThread(getId())
00120                     - this.taskStartTime);
00121         }
00122         return secondsElapsed > 0.0 ? secondsElapsed : 0.0;
00123     }
00124 
00125     public Task getTask() {
00126         return this.runningTask;
00127     }
00128 
00129     public String getCurrentStatusString() {
00130         switch (this.currentStatus) {
00131             case NOT_STARTED:
00132                 return "not started";
00133             case RUNNING:
00134                 return "running";
00135             case PAUSED:
00136                 return "paused";
00137             case CANCELLING:
00138                 return "cancelling";
00139             case CANCELLED:
00140                 return "cancelled";
00141             case COMPLETED:
00142                 return "completed";
00143             case FAILED:
00144                 return "failed";
00145         }
00146         return "unknown";
00147     }
00148 
00149     public String getCurrentActivityString() {
00150         return (isComplete() || (this.currentStatus == Status.NOT_STARTED)) ? ""
00151                 : this.taskMonitor.getCurrentActivityDescription();
00152     }
00153 
00154     public double getCurrentActivityFracComplete() {
00155         switch (this.currentStatus) {
00156             case NOT_STARTED:
00157                 return 0.0;
00158             case RUNNING:
00159             case PAUSED:
00160             case CANCELLING:
00161                 return this.taskMonitor.getCurrentActivityFractionComplete();
00162             case CANCELLED:
00163             case COMPLETED:
00164             case FAILED:
00165                 return 1.0;
00166         }
00167         return 0.0;
00168     }
00169 
00170     public boolean isComplete() {
00171         return ((this.currentStatus == Status.CANCELLED)
00172                 || (this.currentStatus == Status.COMPLETED) || (this.currentStatus == Status.FAILED));
00173     }
00174 
00175     public Object getFinalResult() {
00176         return this.finalResult;
00177     }
00178 
00179     public void addTaskCompletionListener(TaskCompletionListener tcl) {
00180         this.completionListeners.add(tcl);
00181     }
00182 
00183     public void removeTaskCompletionListener(TaskCompletionListener tcl) {
00184         this.completionListeners.remove(tcl);
00185     }
00186 
00187     protected void fireTaskCompleted() {
00188         for (TaskCompletionListener listener : this.completionListeners) {
00189             listener.taskCompleted(this);
00190         }
00191     }
00192 
00193     public void getPreview(ResultPreviewListener previewer) {
00194         this.taskMonitor.requestResultPreview(previewer);
00195         this.latestPreviewGrabTime = getCPUSecondsElapsed();
00196     }
00197 
00198     public Object getLatestResultPreview() {
00199         return this.taskMonitor.getLatestResultPreview();
00200     }
00201 
00202     public double getLatestPreviewGrabTimeSeconds() {
00203         return this.latestPreviewGrabTime;
00204     }
00205 }
 All Classes Namespaces Files Functions Variables Enumerations