C#

class Program
    {
        static SerialPort sp = new SerialPort("COM8", 56000, Parity.None, 8);

        static void Main(string[] args)
        {
            if(!sp.IsOpen)
                sp.Open();
            sp.WriteLine("AT+DS44=?");
            sp.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);

            ThreadStart ts = new ThreadStart(f);
            Thread t = new Thread(ts);
            t.Start();
        }

        static void f()
        {
            while (true) ;
        }

        static void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            Console.WriteLine("DataRecieved..............................");
            string str = sp.ReadLine();
            Console.WriteLine(str + "......................................");
        }
    }

private double timeOccurance2(string target)
      {
         string trial = string.Empty;
         double intialTime = DateTime.Now.ToOADate();
         Random rand = new Random();

         while (trial != target)
         {
             StringBuilder b = new StringBuilder();
             char[] ch = new char[target.Length];
             for (int i = 0; i < target.Length; i++)
            {
	    //here I have restricted possible characters to ~0-9
               ch[i] = Convert.ToChar(Convert.ToInt32(Math.Floor(10 * rand.NextDouble() + 48)));
            }

            for (int i = 0; i < target.Length; i++)
            {
               b.Append(ch[i].ToString());
            }

            trial = b.ToString();
         }

         double finalTime = DateTime.Now.ToOADate();
         return 24 * 60 * 60 * (finalTime - intialTime);
      }

private void button1_Click(object sender, EventArgs e)
     {
        for (int i = 1; i <= 40; i++)
        {
           BackgroundWorker Computation = new BackgroundWorker();
           Computation.DoWork += new DoWorkEventHandler(Computation_DoWork);
           Computation.RunWorkerCompleted += new RunWorkerCompletedEventHandler(Computation_RunWorkerCompleted);
           Computation.RunWorkerAsync();

     private void Computation_DoWork(object sender, DoWorkEventArgs e)
     {
        e.Result = timeOccurance2("123456").ToString();
     }

     private void Computation_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
     {
        richTextBox1.Text += (string)(e.Result);
        richTextBox1.Text += (char)(10);
     }

public partial class main4 : Form<br />
{<br />
        private UserControl1 userControl1 = new UserControl1();<br />
        public main4()<br />
        {<br />
            InitializeComponent();<br />
            this.Controls.Add(userControl1);            <br />
        }       <br />
    }