Using lock with Threading.Timer

Question

I have a Windows Service application which uses a Threading.Timer and a TimerCallback to do some processing at particular intervals. I need to lock

Answer 1

The worst that can happen if the processing code takes more than 10s to execute is that you will be wasting 1 threadpool thread every time there's a new callback called (they will be waiting for in the lock statement). And if you take all the threadpool threads HttpWebRequest, ASP.NET, asynchronous delegate invocations... will suffer.

What I would do is to schedule the first callback immediately. Then, if you really need your DoSomething() to be called every 10s:

public void DoSomething ()
{
       DateTime start = DateTime.UtcNow;
       ...
       TimeSpan elapsed = (DateTime.UtcNow - start);
       int due_in = (int) (10000 - elapsed.TotalMilliseconds);
       if (due_in < 0)
           due_in = 0;
       timer.Change (due_in, Timeout.Infinite);
}

Or something along that line.