Support for a real-time transactional model in distributed Ada

Abstract

This paper presents a proposal to integrate a generic technique to express complex scheduling and timing parameters of distributed transactions as a part of the Distributed Systems Annex of Ada (DSA). The technique allows real-time middleware implementations to change their scheduling policies for both the processing nodes and the networks with a minimal interference in the application code. The proposed mechanisms are managed by the middleware in a transparent way. The only requirement is an initial configuration operation, which can be generated automatically, and a single operation call to set an event identifier in each of the tasks that initiates a distributed transaction. The automatic process used to obtain the initial configuration of the distributed application, based on a real-time model, is also proposed. The implementation of this proposal is currently being developed.