Toward Object-oriented Modeling in SCCharts

Object orientation is a powerful and widely used paradigm for abstraction and structuring in programming. Many languages are designed with this principle or support different degrees of object orientation. In synchronous languages, originally developed to design embedded reactive systems, there are only few object-oriented influences. However, especially in combination with a statechart notation, the modeling process can be improved by facilitating object orientation as we argue here. At the same time the graphical representation can be used to illustrate the object-oriented design of a system. Synchronous statechart dialects, such as the SCCharts language, provide deterministic concurrency for specifying safety-critical systems. Using SCCharts as an example, we illustrate how an object-oriented modeling approach that supports inheritance can be introduced. We further present how external, i.e., host language, objects can be included in the SCCharts language. Specifically, we discuss how the recently developed concepts of scheduling directives and scheduling policies can be used to ensure the determinism of objects while retaining encapsulation.