Abstract

Exception handling in complex concurrent and distributed systems (e.g. ones involving cooperating rather than just competing activities) is often a necessary, but difficult task. No widely accepted models or approaches exist in this area. The object-oriented paradigm, for all its structuring benefits, and real-time requirements each add further difficulties to the design and implementation of exception handling in such systems. In this paper, we develop a general structuring framework based on the coordinated atomic (CA) action concept for handling exceptions in distributed object systems, in which exceptions in both the value and the time domain are taken into account. In particular, we attempt to attack several difficult problems related to real-time system design and error recovery, including action-level timing constraints, time-triggered CA actions, and time-dependent exception handling. The proposed framework is then demonstrated and assessed using an industrial real-time application.

Keywords

atomic actions, cooperative concurrency, distributed systems, exception handling, exception resolution, real-time constraints