System.Diagnostics.Stopwatch returns negative numbers in Elapsed... properties

Question

Is it normal behaviour that Stopwatch can return negative values? Code sample below can be used to reproduce it.

 while (true)         {             Stopwatch sw = new Stopwatch();             sw.Start();             sw.Stop();              if (sw.ElapsedMilliseconds < 0)                 Debugger.Break();          } 

The only place where I can reproduce negative numbers is my virtual machine (hosted by Hyper-V on a 8-core machine)

Answer 1

This is a bug. It doesn't seem to have a lot of attention around it, through, so I'd suggesting following up with that report.

The uninspiring workaround appears to be to ignore negative values:

long elapsedMilliseconds = Math.Max(0, stopwatch.ElapsedMilliseconds);