Question

In my website, I am using a thread to perform a process in background. I start the thread on a button click.

Now the problem I face is that it seems to time out and stop. Basically it stops updating the database.

What could be wrong?

Here is my code:

 public static class BackgroundHelper 
 {
    private static readonly object _syncRoot = new object(); 
    private static readonly ManualResetEvent _event = new ManualResetEvent(false); 
    private static Thread _thread;
    public static bool Running 
    { 
        get; 
        private set;
    }
    public static void Start()
    {    
        lock (_syncRoot) 
        {
          if (Running)
                return; 
            Running = true;
            // Reset the event so we can use it to stop the thread.
            _event.Reset(); 
            // Star the background thread.
            _thread = new Thread(new ThreadStart(BackgroundProcess)); 
            _thread.Start();
        }
    }

    public static void Stop()   
    {
        lock (_syncRoot)
        {
            if (!Running)
                return;
            Running = false; 
            // Signal the thread to stop.
            _event.Set();
            // Wait for the thread to have stopped.
            _thread.Join(); 
            _thread = null;
        } 
    }   

    private static void BackgroundProcess()  
    { 
        int count = 0;
        DateTime date1 = new DateTime(2011, 2, 5);
        while (System.DateTime.Compare(System.DateTime.Now, date1) < 0)
        {
            downloadAndParse();  
            // Wait for the event to be set with a maximum of the timeout. The
            // timeout is used to pace the calls to downloadAndParse so that 
            // it not goes to 100% when there is nothing to download and parse.
            bool result = _event.WaitOne(TimeSpan.FromSeconds(45));
            // If the event was set, we're done processing.
           // if (result)
             //   break;
            count++; 
        }
    }

    private static void downloadAndParse()
    {
        NewHive.MyServ newServe = new NewHive.MyServ();
        NewHive.CsvDownload newService = new NewHive.CsvDownload();
        //NewHive.MyServ newServe = new NewHive.MyServ();
        string downloadSuccess = newService.CsvDownloader();
        if (downloadSuccess == "Success")
        {
            string parseSuccess = newService.CsvParser();

        }
        newServe.updateOthersInPosition();
    }
}

Answer 1

A background thread can only live as long as the thread that calls it is alive. Since the web server has a finite request/response lifecycle your background’s process can’t exceed this time limit. Once the timeout is reached on the web server, the server will generate the response (timeout), push it to the client and stop the thread. This event will kill your background thread, so if it’s mid-update on the database it’ll just stop. If you’re doing something like writing to a file, it’ll leave that file open, locked and improperly written (requiring a reboot to regain access to the corrupted file).