BackgroundThread.cs

#region Copyright

//
// Copyright (c) Phoenix Contact GmbH & Co. KG. All rights reserved.
// Licensed under the MIT. See LICENSE file in the project root for full license information.
//

#endregion Copyright

using Iec61131.Engineering.Prototypes.Common;
using Iec61131.Engineering.Prototypes.Methods;
using Iec61131.Engineering.Prototypes.Types;
using Iec61131.Engineering.Prototypes.Variables;
using System;
using System.Threading;
using System.Iec61131Lib;

namespace ExampleLib
{
 [FunctionBlock]
 public class BackgroundThread
 {
 [InOut]
 public bool startThread;

 [Input]
 public short setPrio;

 [Output]
 public bool done;

 public Thread StaticCaller;
 private bool m_startThread;

 [Initialization]
 public void __Init()
 {
 // Create the thread object, passing in the
 // serverObject.ThreadBody method using a
 // ThreadStart delegate.
 ThreadStart threadStarter = new ThreadStart(BackgroundServerThread.ThreadBody);
 StaticCaller = new Thread(threadStarter)
 {
 Priority = ThreadPriority.Lowest,
 Name = "backgroundThread"
 };

 StaticCaller.Start();
 }

 ~BackgroundThread()
 {
 BackgroundServerThread.TerminateBackgroundThread = true;
 }

 [Execution]
 public void __Process()
 {
 if (BackgroundHelper.IsRisingEdge(startThread, ref m_startThread))
 {
 done = false;
 BackgroundServerThread.doSomething = true;
 }
 done = BackgroundServerThread.done;

 if (BackgroundHelper.IsFallingEdge(startThread, ref m_startThread))
 {
 BackgroundServerThread.doSomething = false;
 done = false;
 startThread = false;
 }
 }
 }
 public class BackgroundServerThread
 {
 public static bool doSomething;
 public static bool done;
 public static bool TerminateBackgroundThread;
 public static void ThreadBody()
 {
 while (true) // run so long as initiator exists.
 {
 if(TerminateBackgroundThread == true)
 {
 break; // terminates this thread if initiator is removed
 }
 done = false;
 if (BackgroundHelper.IsRisingEdge(doSomething, ref doSomething))
 {
 int a = 0;
 int b = 1;
 int n = 300000;
 // If something is to do we do this. 
 // Example: In N steps compute Fibonacci sequence iteratively .
 for (int i = 0; i < n; i++)
 {
 int temp = a;
 a = b;
 b = temp + b;
 }
 done = true; // Initiator of this thread looks on this bit to detect the job has been done.
 }
 else
 {
 // Pause for a moment to provide a delay to make
 // threads more apparent.
 Thread.Sleep(100);
 }
 }
 }
 }
 public static class BackgroundHelper
 {
 public static bool IsRisingEdge(bool value, ref bool _value)
 {
 if (value && !_value)
 {
 _value = value;
 return true;
 }
 return false;
 }
 public static bool IsFallingEdge(bool value, ref bool _value)
 {
 if (!value && _value)
 {
 _value = value;
 return true;
 }
 return false;
 }
 }
}