[chuck-users] durations and control structures

Hi there list, I'm new to this chuck business and am trying to get a handle on a number of things - timing and durations are one of them. If I have a chunk of code that I'd like to run for a specific duration of time, how could I go about defining this in the control structure? something like while (duration condition here) { do this } I understand that I could use some kind of counter that (de/) increments each iteration and use this to control the loop with a < or > operation, but one thing I might like to do in performance is vary the (poll rate) => now, and it would be nice for my control structure timing to remain intact with such operations. I'm sure there's a simple answer, but it avoids me. Thanks, --Tim