ini/trakem2/utils/Dispatcher.java

   1 /**
   2
   3 TrakEM2 plugin for ImageJ(C).
   4 Copyright (C) 2008 Albert Cardona.
   5
   6 This program is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU General Public License
   8 as published by the Free Software Foundation (http://www.gnu.org/licenses/gpl.txt )
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18
  19 You may contact Albert Cardona at acardona at ini.phys.ethz.ch
  20 Institute of Neuroinformatics, University of Zurich / ETH, Switzerland.
  21 **/
  22
  23 package ini.trakem2.utils;
  24
  25 import java.util.ArrayList;
  26 import javax.swing.SwingUtilities;
  27
  28 public class Dispatcher extends Thread {
  29         private final class Task {
  30                 Runnable run;
  31                 boolean swing;
  32                 Task(Runnable run, boolean swing) {
  33                         this.run = run;
  34                         this.swing = swing;
  35                 }
  36         }
  37         private final ArrayList<Task> tasks = new ArrayList<Task>();
  38         private final Lock lock = new Lock();
  39         private boolean go = true;
  40
  41         public Dispatcher(String tag) {
  42                 super("T2-Dispatcher" + (null != tag ? " " + tag : ""));
  43                 setPriority(Thread.NORM_PRIORITY);
  44                 setDaemon(true);
  45                 start();
  46         }
  47         public Dispatcher() {
  48                 this(null);
  49         }
  50         public void quit() {
  51                 this.go = false;
  52                 synchronized (this) { notify(); }
  53         }
  54         public boolean isQuit() {
  55                 return go;
  56         }
  57
  58         private boolean accept = true;
  59
  60         public void quitWhenDone() {
  61                 accept = false;
  62                 quit();
  63         }
  64
  65         /** Submits the task for execution and returns immediately. */
  66         public void exec(final Runnable run) { exec(run, false); }
  67         public void execSwing(final Runnable run) { exec(run, true); }
  68         public void exec(final Runnable run, final boolean swing) {
  69                 if (!accept) {
  70                         Utils.log2("Dispatcher: NOT accepting more tasks!");
  71                         return;
  72                 }
  73                 synchronized (lock) {
  74                         lock.lock();
  75                         tasks.add(new Task(run, swing));
  76                         lock.unlock();
  77                 }
  78                 synchronized (this) { notify(); }
  79         }
  80         /** Executes one task at a time, in the same order in which they've been received. */
  81         public void run() {
  82                 while (go || (!accept && tasks.size() > 0)) {
  83                         try {
  84                                 synchronized (this) { wait(); }
  85                                 if (!go) return;
  86                                 while (tasks.size() > 0) {
  87                                         Task task = null;
  88                                         synchronized (lock) {
  89                                                 lock.lock();
  90                                                 if (tasks.size() > 0) {
  91                                                         task = tasks.remove(0);
  92                                                 }
  93                                                 lock.unlock();
  94                                         }
  95                                         if (null == task) continue;
  96                                         try {
  97                                                 if (task.swing) SwingUtilities.invokeAndWait(task.run);
  98                                                 else task.run.run();
  99                                         } catch (Throwable t) { IJError.print(t); }
 100                                 }
 101                         } catch (Throwable e) { IJError.print(e); }
 102                 }
 103         }
 104 }