Distributed computing and safety critical systems in Ada

Sammanfattning: A system architecture for building large distributed real-time systems is presented. By placing the core run-time system (RTS) functionality in a edicatednetwork node, called the controller, distribution of a single Ada 83 program with preservation of the tasking semantics is possible. RTS proxies on the architecture's processing nodes communicate with the controller over a high-speed network. The communication overhead is shown to be acceptable. Thiswork includes the development of an algorithm for task termination intendedfor hardware implementation.A model for distributed systems in Ada 95 based on the Linda model ispresented. The implementation treats Linda tuples as typed objects in theirown right. This type safe Linda is adopted as a distributed shared memory forthe implementation of shared passive packages.A formal model of a run-time kernel for the Ada 95 Ravenscar subset suitablefor safety critical systems is presented. The kernel and applications are modelledusing timed automata. Both functional and timing properties of the kernelas well as timing properties of the application are verified using the real-time model checker UPPAAL. Guidelines for transforming Ada applications into timed automata are given.