How to “sleep” until timeout or cancellation is requested

I just blogged about it here:

CancellationToken and Thread.Sleep

in Short:

var cancelled = token.WaitHandle.WaitOne(TimeSpan.FromSeconds(5));

In your context:

void MyFunc (CancellationToken ct)
{
   //... 
   // simulate some long lasting operation that should be cancelable 
   var cancelled = ct.WaitHandle.WaitOne(TimeSpan.FromSeconds(10));
}