Feature-oriented refactoring proposal for transaction level models in SoCLib

Transaction level is not a single abstraction level. According to the OSCI TLM-2.0 language reference manual, it is divided further into: untimed (UT), loosely-timed (LT) and approximately-timed (AT). Different sub-level serves for different use case. But SoCLib provides only one type of Transaction Level Model (TLM) for each component, i.e. TLM-DT. Here DT means Distributed Time, and TLM-DT model can be equated with LT model. So it is a great challenge to find a good way to develop the other two types of TLM for each component. It is obviously unwise to develop them from scratch, since they share same functionalities with the TLM-DT model which is possible to be reused in their implementation. In this paper, we propose to refactor SoCLib with Feature-Oriented Programming (FOP) methodology, which can make the functionality of each TLM-DT model reusable and solve the above problem. Although this paper seems specific to SoCLib, the idea of transaction level modeling with FOP methodology is in fact general.