Design principles for highly reusable concurrent object-oriented systems

Designing a concurrent object oriented language isn’t an easy task. After many years of research, the merging of concurrency and object oriented paradigms hasn’t been achieved in a totally satisfactory way. Although recent models have partly solved important problems such as the inheritance anomaly, they do still present limitations due to the lack of reusability and adaptability. Approaches based on separation of concerns appear to point to the development of models which achieve effectively those requirements. In this essay we argu e that the establishment of orthogonal design principles should be useful in this respect, as it was in other fields of object systems research. We‘ll propose these principles basing on well-known principles of design of programming languages and orthogonal persistence. In order to show the adequacy of these principles, we present CoJava, a model based on the separation of concurrent and functional aspects by means of their implementation in different component classes and their composition at runtime. CoJava has been designed applying our principles to offer a high degree of orthogonality, which results in better reusability than previous models.