A Reflective Approach for Supporting the Dynamic Evolution of Component Types

The increasing complexity of software systems requires a continuous revisions process in order to correct errors or to add new functionalities. However, the nature of some systems makes unfeasible their stopping to integrate changes. Dynamic evolution of types is a feature that provides support for changing completely at runtime the types that a system is composed of. Thus, a system is able to integrate new types, or to modify/remove existing ones, while it is running. In software architecture, these types are component specifications, and its instantiations, component instances. This paper presents a reflective approach for providing dynamic evolution of component types and instances in a decentralized way. Each type can be evolved separately from others, and each one of its instances evolves asynchronously, only after finishing their running transactions. The approach is reflective since it dynamically provides editable specifications of the type to evolve, and reflects changes on both types and instances while they are running.