Implementing Synchronous Co-ordinated Atomic Actions Based on Forward Error Recovery

Coordinated atomic action concept is proposed as a means for providing fault tolerance in complex object oriented systems which incorporate both cooperative and competitive concurrency. This paper has two purposes: to discuss a particular implementation of this concept and to address many implementation issues which are common for any experiments with this concept. Our implementation relies on a thoroughly designed set of programming conventions for the standard Ada (Ada95) language and uses forward error recovery which incorporates asynchronous exception handling and concurrent exception resolution. We utilise the peculiarities of Ada as much as possible, which makes our approach practical and useful for many critical applications with high dependability requirements. This scheme offers a basic framework for using coordinated atomic actions and allows us to continue experimenting with them.