Threadpool or TPL for a long running tasks RSS

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  samk1984

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  Threadpool or TPL for a long running tasks

  Apr 28, 2015 07:56 AM|samk1984|LINK

  
  I have a windows service which sends out emails after a lengthy process. This service keep on fetching email data from DB table, whenever there is a table entry and process it and will send it out.

  Currently it is a multi thread application where we configure Thread count up to 25 in production server(which is solely for this purpose) as this is meant to run 24x7x365 . But we see only 2 active threads. What could be the reason?

  Also I wish to change the threading code here using thread pool or TPL. Could you please suggest me a better way to handle this scenario ?

  Thanks in Advance !

  //Sample code below

  Thread[] threads;
  int ThreadCount = 25;
  private void StartProcess()
  {
  Create new threads
  if (Threads == null)
  {
  // Create array of threads based on the configuration
  threads = new Thread[ThreadCount];
  for (int i = 0; i < ThreadCount; i++)
  {
  Thread[] threads[i] = new Thread(new ThreadStart(SendEmail));
  threads[i].Start();
  }
  }
  else
  {
  resume it if exists
  for (int j = 0; j < threads.Length; j++)
  {
  if (threads[j].ThreadState == Threading.ThreadState.Suspended)
  {
  threads[j].Resume();
  }
  }
  }
  }
  public void SendEmail()
  {
  while (Thread.CurrentThread.ThreadState == System.Threading.ThreadState.Running)
  {
  // send email code
  Thread.Sleep(duration);
  }
  }

  Thread Threadpool parallel

• • Reply
  csharpgreg

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  188 Posts

  Re: Threadpool or TPL for a long running tasks

  Apr 28, 2015 01:14 PM|csharpgreg|LINK

  Hello Samk1984! Thanks for your post!

  Using the new Task Parallel Library (TPL) is a piece of cake. It's so much simpler and easier than the old way.

  You can store your thread count in the App.config file and do it this way:

  using System.Threading.Tasks;
  
  int threadCount;
  int.TryParse(ConfigurationManager.AppSettings["ThreadCount"], out threadCount);
  
  var po = new ParallelOptions { MaxDegreeOfParallelism = threadCount, TaskScheduler = null };
  
  // Get your list of emails here
  lstEmail = GetEmails();
  
  // Multi-thread - process each email
  Parallel.ForEach(lstEmail, po, plan =>
  {
  
     // Everything in here will be multi-threaded using the TPL
  
  }

  Also, just a quick architecture note - you could also set up a timer in your Windows Service and have the service check for new emails every n minutes - if any emails exist you could launch a separate multi-threaded .NET console app that processes the emails:

  using System.ServiceProcess;
  
  public class WinService : ServiceBase
  {
          private readonly Timer _timer = new Timer();
  
          protected override void OnStart(string[] args)
          {
              Logger.Info("Service Started");
  
              // Raise event
              _timer.Elapsed += timer_Elapsed;
  
              // 1000 is the number of milliseconds in a second
              // 60 is the number of seconds in a minute
              _timer.Interval = 1000 * 60;
  
              _timer.Enabled = true;
              _timer.Start();
          }
  
          // Handles event, every n minutes
          private static void timer_Elapsed(object sender, EventArgs e)
          {
                LaunchEmailEngine();
          }
  
          private static void LaunchEmailEngine(string args)
          {
                  var startInfo = new ProcessStartInfo
                  {
                      FileName = Helper.GetAppSetting("EngineLocation"),
                      Arguments = args
                  };
                  Process.Start(startInfo);
          }
  
  }

  Regards!

  Thread Threadpool parallel