tmf/org.eclipse.tracecompass.tmf.ui/src/org/eclipse/tracecompass/internal/provisional/tmf/ui/views/timegraph2/swtjfx/LatestJobExecutor.java

   1 /*******************************************************************************
   2  * Copyright (c) 2016 EfficiOS Inc., Alexandre Montplaisir
   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
  10 package org.eclipse.tracecompass.internal.provisional.tmf.ui.views.timegraph2.swtjfx;
  11
  12 import java.lang.ref.WeakReference;
  13
  14 import org.eclipse.core.runtime.jobs.Job;
  15 import org.eclipse.jdt.annotation.Nullable;
  16
  17 public class LatestJobExecutor {
  18
  19     /**
  20      * The latest job that was schedule in this queue.
  21      */
  22     private WeakReference<@Nullable Job> fLatestJob = new WeakReference<>(null);
  23
  24     public LatestJobExecutor() {
  25     }
  26
  27     public synchronized void schedule(Job newJob) {
  28         Job latestJob = fLatestJob.get();
  29         if (latestJob != null) {
  30             /*
  31              * Cancel the existing job. Here's hoping it cooperates and ends
  32              * quickly!
  33              */
  34             latestJob.cancel();
  35         }
  36
  37         /* Start the new job */
  38         fLatestJob = new WeakReference<>(newJob);
  39         newJob.schedule();
  40     }
  41
  42 }