I'm making an application that needs some pretty tight timing, and the Stopwatch class is the perfect solution. However, I noticed sometimes, when running on a small panel PC, the Stopwatch values were way off. I added some debug printouts that monitor the value of the stopwatch every 200 ms or so:
0:00:197
0:00:502
0:00:702
...
0:03:356
0:12:93
0:13:21
0:13:421
...
How could it possibly jump from ~3 seconds to ~13 seconds? I now see that the underlying function QueryPerformanceCounter() is buggy (Beware of QueryPerformanceCounter()), but I get the sense that something else is going on here.
Any insight is appreciated.
Update:
Here's a little more detail on my code: it's pretty straightforward. It's a WPF application that creates a new Stopwatch object on startup, and then kicks it off via Start(). I then create a DispatcherTimer, like so:
displayTimer = new DispatcherTimer();
displayTimer.Tick += display_Tick;
displayTimer.Interval = DISPLAY_INTERVAL_TIMESPAN;
where the timespan is 200 ms. My debug code simply prints out the value of the Stopwatch object every time the dispatchTimer ticks.
Update2:
A fun Microsoft support article is Performance counter value may unexpectedly leap forward.