Question

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How to measure how long is a function running?

I’m writing a UDP chat with reliable data transfer. I need to start a timer when a packet is sent, and stop it as soon it receives an answer from the server (ACK – acknowledgment).

Here is my code:

 private void sendButton_Click(object sender, EventArgs e)
 {
     Packet snd = new Packet(ack, textBox1.Text.Trim());
     textBox1.Text = string.Empty;
     Smsg = snd.GetDataStream();//convert message into array of bytes to send.
     while (true)
     {
        try
         {  // Here I need to Start a timer!
           clientSock.SendTo(Smsg, servEP); 
           clientSock.ReceiveFrom(Rmsg, ref servEP);
           //Here I need to stop a timer and get elapsed amount of time.

           Packet rcv = new Packet(Rmsg);
           if (Rmsg != null && rcv.ACK01 != ack)
               continue;

           if (Rmsg != null && rcv.ACK01 == ack)
           {
            this.displayMessageDelegate("ack is received :"+ack);
            ChangeAck(ack);
            break;
           }

Thank you.

Answer 1

Don’t use a Timer. It’s not usually accurate enough, and there’s a simpler object designed for just this work: The Stopwatch class.

Code sample from the MSDN documentation:

using System;
using System.Diagnostics;
using System.Threading;
class Program
{
    static void Main(string[] args)
    {
        Stopwatch stopWatch = new Stopwatch();
        stopWatch.Start();
        Thread.Sleep(10000);
        stopWatch.Stop();
        // Get the elapsed time as a TimeSpan value.
        TimeSpan ts = stopWatch.Elapsed;

        // Format and display the TimeSpan value. 
        string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
            ts.Hours, ts.Minutes, ts.Seconds,
            ts.Milliseconds / 10);
        Console.WriteLine("RunTime " + elapsedTime);
    }
}

In your case, you’d start it when the packet is sent, and stop it when the ack is received.