Implementation of blocking coordinated atomic actions based on forward error recovery

The coordinated atomic action concept was proposed as a means for providing fault tolerance in complex objectoriented systems that incorporate both cooperative and competitive concurrency. This paper has two purposes: to discuss a particular implementation of this concept and to address a number of the implementation issues that are common to any experiments with this concept. Our implementation relies on a detailed set of programming conventions for the standard Ada 95 language and uses a scheme of forward error recovery incorporating concurrent exception handling and resolution. Ada 95 has a number of unique features which make it a particularly good choice for our experiments. We believe that our approach is practical and useful for many critical applications with high dependability requirements.