Message pattern specifications: a new technique for handling errors in parallel object oriented systems

As object oriented techniques enable the fabrication of ever more sophisticated systems, the need grows for a mechanism to ensure the consistent and 'correct' behaviour of each object at run-time. We describe a new, in-source specification mechanism, Message Pattern Specifications (MPS), to directly satisfy this need in a succinct, orthogonal and disciplined manner. Targeted for use in parallel object oriented systems, MPS allows programmers to enunciate the 'legal' patterns of run-time behaviour in which their objects may engage. Furthermore, it supports the definition of methods for object recovery or graceful failure in case these specifications are violated during execution.