Concurrent correspondent modules: a fault tolerant Ada implementation

The authors propose the concept of concurrent correspondent modules as a strategy to implement software fault tolerance. It is based on the concurrent execution of the primary, and its redundant correspondent versions. Error detection and forward error recovery are performed by the comparative test. Using Ada tasks in conjunction with the abort facility, concurrent correspondent modules are easily and efficiently implemented. The use of concurrent Ada enhances the power of concurrent correspondent modules, making this an elegant, effective and feasible alternative to other fault-tolerant approaches.<>