| /***************************************************************** |
| * Copyright (c) 2021 Joerg Kubitz and others |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * Joerg Kubitz - Initial API and implementation |
| *****************************************************************/ |
| |
| package org.eclipse.debug.internal.ui.model.elements; |
| |
| import java.util.concurrent.ConcurrentLinkedQueue; |
| |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.core.runtime.IProgressMonitor; |
| import org.eclipse.core.runtime.IStatus; |
| import org.eclipse.core.runtime.Status; |
| import org.eclipse.core.runtime.jobs.Job; |
| |
| /** |
| * A singleton SerialExecutor job instance can be used to execute Runnable |
| * objects offered by {@link #schedule(Runnable)} method in order of they |
| * submission, one after another. |
| */ |
| public final class SerialExecutor extends Job { |
| |
| private final ConcurrentLinkedQueue<Runnable> queue; |
| private final Object myFamily; |
| |
| /** |
| * @param jobName descriptive job name |
| * @param family non null object to control this job execution |
| **/ |
| public SerialExecutor(String jobName, Object family) { |
| super(jobName); |
| Assert.isNotNull(family); |
| this.myFamily = family; |
| this.queue = new ConcurrentLinkedQueue<>(); |
| setSystem(true); |
| } |
| |
| @Override |
| public boolean belongsTo(Object family) { |
| return myFamily == family; |
| } |
| |
| @Override |
| protected IStatus run(IProgressMonitor monitor) { |
| Runnable action = queue.poll(); |
| try { |
| if (action != null) { |
| action.run(); |
| } |
| } finally { |
| if (!queue.isEmpty()) { |
| // in case actions got faster scheduled then processed reschedule: |
| schedule(); |
| } |
| } |
| return Status.OK_STATUS; |
| } |
| |
| /** |
| * Enqueue an action asynchronously. |
| **/ |
| public void schedule(Runnable action) { |
| queue.offer(action); |
| schedule(); // will reschedule if already running |
| } |
| } |