Modeling and Schedulability Analysis of Hard Real-Time Distributed Systems Based on Ada Components

The paper proposes a methodology for modeling distributed real-time applications written in Ada 95 and its Annexes D and E. The real-time model obtained is analyzable with a set of tools that includes multiprocessor priority assignment and worst-case schedulability analysis for checking hard real-time requirements. This methodology models independently the platform (processors, communication networks, operating systems, or peripheral drivers), the logical components used (processing requirements, shared resources or remote components), and the real-time situations of the application itself (real-time transactions, workload or timing requirements). It automates the modeling of local and remote access to distributed services. The methodology is formulated with UML, and therefore the software logic design as well as its real-time model may be represented inside any UML CASE tool. The real-time model obtained is analyzable with a set of tools that includes multiprocessor priority assignment and worst-case schedulability analysis for checking hard real-time requirements.