A refinement of the fragmented object model

Fragmented objects offer an interesting alternative to the use of uniform transparent object references in distributed systems. This novel paradigm for distributed programming provides facilities for the encapsulation of policy issues as well as implementation details such as communication mechanisms and consistency requirements. At the same time a clean and comprehensible model is offered to both FO designers and client programmers. Certain mechanisms are generalised to increase both the power and the expressiveness of the model. In particular, FO interfaces are extended to include upcalls and a new internal model, based on the fragment factory, is introduced