Question

I know how to start a function in x seconds, its something like this:

private Timer timer1; 
public void InitTimer()
{
    timer1 = new Timer();
    timer1.Tick += new EventHandler(timer1_Tick);
    timer1.Interval = 2000; // in miliseconds
    timer1.Start();
}

private void timer1_Tick(object sender, EventArgs e)
{
    function1();
    function2();
    function3();
}

The problem here: The functions cannot run at the same time. Function2 can only run if Function1 is done. But I want them running at the same time. Thats why I could do this:

private void timer1_Tick(object sender, EventArgs e)
{
   Parallel.Invoke(
     () => Function1(),
     () => Function2(),
     () => Function3()
   );
}

Is this the smartest way to do it in c#? What I dont understand with Parallel.Invoke: what if my timer is set for 5 sec and after 5 sec function1,2 and 3 are not done but I call them all again. Do I start these functions in a new thread? Are there after some calls x-threads running function1() (at the same time)? Wondering is that really healthy.

If somebody would like to get more information: function1 is just there to copy file x from folder a to b, function2 is only there to read all files from folder b and save the information and function3 is only there to check the connection and if there is a connection send the appropriate file to somebody.

Any suggestions to the code? Thank you

Answer 1

Use System.Threading.Timer to schedule the callback on a ThreadPool thread, so you don’t need to create a new task. It also allows you to control the intervals to prevent the overlap of callbacks.

// fired after 5 secs, but just once.
_timer = new System.Threading.Timer(Callback, null, 5000, Timeout.Infinite);

// on the callback you must re-schedule the next callback time;
private void Callback(Object state) {
   Function1();
   Function2();

   // schedule the next callback time 
   _timer.Change(5000, Timeout.Infinite);
}