#region License Information /* HeuristicLab * Copyright (C) 2002-2008 Heuristic and Evolutionary Algorithms Laboratory (HEAL) * * This file is part of HeuristicLab. * * HeuristicLab is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * HeuristicLab is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with HeuristicLab. If not, see . */ #endregion using System; using System.Collections.Generic; using System.Text; using System.Threading; using HeuristicLab.Hive.Contracts; namespace HeuristicLab.Hive.Client.Common { /// /// Queue for the communication between threads and AppDomains. The Queue is threadsafe and uses a semaphore /// public class MessageQueue : MarshalByRefObject { private static MessageQueue instance = null; private Queue queue = null; private Semaphore semaphore = null; /// /// Returns the Instance of the MessageQueue. If the instance is null, it will be created. /// This is a Implementation of the Singleton pattern /// /// the MessageQueue Instance public static MessageQueue GetInstance() { if (instance == null) { instance = new MessageQueue(); } return instance; } /// /// Sets Lease time to infinite /// /// nothing public override object InitializeLifetimeService() { return null; } /// /// Creates a new MessageQueue Object. /// A new Queue and a Semaphore is created. The Semaphore is set to a max size of 5000. /// private MessageQueue() { queue = new Queue(); semaphore = new Semaphore(0, 5000); } /// /// Returns the oldest MessageContainer Object from the Queue. /// /// the oldest MessageContainer Object public MessageContainer GetMessage() { semaphore.WaitOne(); lock (this) { if (queue.Count > 0) { return queue.Dequeue(); } } return null; } /// /// Adds a MessageContainer Object to the Queue /// /// the MessageContainer public void AddMessage(MessageContainer messageContainer) { lock (this) { queue.Enqueue(messageContainer); semaphore.Release(); } } /// /// Adds a message to the Queue. The MessageContainer Object is built in the Method /// /// the Message public void AddMessage(MessageContainer.MessageType message) { lock (this) { queue.Enqueue(new MessageContainer(message)); semaphore.Release(); } } } }