org.eclipse.linuxtools.tmf/src/org/eclipse/linuxtools/tmf/request/TmfRequestExecutor.java

   1 /*******************************************************************************
   2  * Copyright (c) 2009, 2010 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Francois Chouinard - Initial API and implementation
  11  *******************************************************************************/
  12
  13 package org.eclipse.linuxtools.tmf.request;
  14
  15 import java.util.Queue;
  16 import java.util.concurrent.Executor;
  17 import java.util.concurrent.Executors;
  18 import java.util.concurrent.LinkedBlockingQueue;
  19
  20 /**
  21  * <b><u>TmfRequestExecutor</u></b>
  22  *
  23  * Implement me. Please.
  24  */
  25 public class TmfRequestExecutor implements Executor {
  26
  27         private final Executor fExecutor;
  28         private final Queue<Runnable> fRequests = new LinkedBlockingQueue<Runnable>();
  29         private Runnable fRequest;
  30
  31         public TmfRequestExecutor(Executor executor) {
  32                 fExecutor = executor;
  33         }
  34
  35         public TmfRequestExecutor() {
  36                 this(Executors.newSingleThreadExecutor());
  37         }
  38
  39         public void execute(final Runnable request) {
  40                 fRequests.offer(new Runnable() {
  41                         public void run() {
  42                                 try {
  43                                         request.run();
  44                                 } finally {
  45                                         scheduleNext();
  46                                 }
  47                         }
  48                 });
  49                 if (fRequest == null) {
  50                         scheduleNext();
  51                 }
  52         }
  53
  54         protected synchronized void scheduleNext() {
  55                 if ((fRequest = fRequests.poll()) != null) {
  56                         fExecutor.execute(fRequest);
  57                 }
  58         }
  59
  60         public synchronized void queueRequest(Runnable request) {
  61                 fRequests.add(request);
  62                 scheduleNext();
  63         }
  64
  65 }