A hierarchy of classes has been set up that describes "actions" that need to be performed. Originally designed for the TCLK decoder module, the Action class hierarchy has become generalized enough that its mechanism can be used by any module.
If an application is interested in TCLK events, there should be some method to notify it when one occurs. No one method of notification is applicable in all situations: callback are resource efficient but don't have an upper bound on their execution time,