WaitableCounter.cs :  » GUI » Paint.net » PaintDotNet » Threading » C# / CSharp Open Source

Home
C# / CSharp Open Source
1.2.6.4 mono .net core
2.2.6.4 mono core
3.Aspect Oriented Frameworks
4.Bloggers
5.Build Systems
6.Business Application
7.Charting Reporting Tools
8.Chat Servers
9.Code Coverage Tools
10.Content Management Systems CMS
11.CRM ERP
12.Database
13.Development
14.Email
15.Forum
16.Game
17.GIS
18.GUI
19.IDEs
20.Installers Generators
21.Inversion of Control Dependency Injection
22.Issue Tracking
23.Logging Tools
24.Message
25.Mobile
26.Network Clients
27.Network Servers
28.Office
29.PDF
30.Persistence Frameworks
31.Portals
32.Profilers
33.Project Management
34.RSS RDF
35.Rule Engines
36.Script
37.Search Engines
38.Sound Audio
39.Source Control
40.SQL Clients
41.Template Engines
42.Testing
43.UML
44.Web Frameworks
45.Web Service
46.Web Testing
47.Wiki Engines
48.Windows Presentation Foundation
49.Workflows
50.XML Parsers
C# / C Sharp
C# / C Sharp by API
C# / CSharp Tutorial
C# / CSharp Open Source » GUI » Paint.net 
Paint.net » PaintDotNet » Threading » WaitableCounter.cs
/////////////////////////////////////////////////////////////////////////////////
// Paint.NET                                                                   //
// Copyright (C) dotPDN LLC, Rick Brewster, Tom Jackson, and contributors.     //
// Portions Copyright (C) Microsoft Corporation. All Rights Reserved.          //
// See src/Resources/Files/License.txt for full licensing and attribution      //
// details.                                                                    //
// .                                                                           //
/////////////////////////////////////////////////////////////////////////////////

using PaintDotNet.SystemLayer;
using System;
using System.Diagnostics;
using System.Threading;

namespace PaintDotNet.Threading{
    /// <summary>
    /// Threading primitive that allows you to "count" and to wait on two conditions:
    /// 1. Empty -- this is when we have not dished out any "tokens"
    /// 2. NotFull -- this is when we currently have 1 or more "tokens" out in the wild
    /// Note that the tokens given by Acquire() *must* be disposed. Otherwise things
    /// won't work right!
    /// </summary>
    public class WaitableCounter
    {
        /// <summary>
        /// The minimum value that may be passed to the constructor for initialization.
        /// </summary>
        public static int MinimumCount
        {
            get
            {
                return WaitHandleArray.MinimumCount;
            }
        }

        /// <summary>
        /// The maximum value that may be passed to the construct for initialization.
        /// </summary>
        public static int MaximumCount
        {
            get
            {
                return WaitHandleArray.MaximumCount;
            }
        }

        private sealed class CounterToken
            : IDisposable
        {
            private WaitableCounter parent;
            private int index;

            public int Index
            {
                get
                {
                    return this.index;
                }
            }

            public CounterToken(WaitableCounter parent, int index)
            {
                this.parent = parent;
                this.index = index;
            }

            public void Dispose()
            {
                parent.Release(this);
            }
        }

        private WaitHandleArray freeEvents;    // each of these is signaled (set) when the corresponding slot is 'free'
        private WaitHandleArray inUseEvents;   // each of these is signaled (set) when the corresponding slot is 'in use'

        private object theLock;

        public WaitableCounter(int maxCount)
        {
            if (maxCount < 1 || maxCount > 64)
            {
                throw new ArgumentOutOfRangeException("maxCount", "must be between 1 and 64, inclusive");
            }

            this.freeEvents = new WaitHandleArray(maxCount);
            this.inUseEvents = new WaitHandleArray(maxCount);

            for (int i = 0; i < maxCount; ++i)
            {
                this.freeEvents[i] = new ManualResetEvent(true);
                this.inUseEvents[i] = new ManualResetEvent(false);
            }

            this.theLock = new object();
        }

        private void Release(CounterToken token)
        {
            ((ManualResetEvent)this.inUseEvents[token.Index]).Reset();
            ((ManualResetEvent)this.freeEvents[token.Index]).Set();
        }

        public IDisposable AcquireToken()
        {
            lock (this.theLock)
            {
                int index = WaitForNotFull();
                ((ManualResetEvent)this.freeEvents[index]).Reset();
                ((ManualResetEvent)this.inUseEvents[index]).Set();
                return new CounterToken(this, index);
            }
        }

        public bool IsEmpty()
        {
            return IsEmpty(0);
        }

        public bool IsEmpty(uint msTimeout)
        {
            return freeEvents.AreAllSignaled(msTimeout);
        }

        public void WaitForEmpty()
        {
            freeEvents.WaitAll();
        }

        public int WaitForNotFull()
        {
            int returnVal = freeEvents.WaitAny();
            return returnVal;
        }

    }
}
www.java2v.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.