Design and Implementation of a Ravenscar Extension for Multiprocessors

• Published in: Reliable Software Technologies - Ada-Europe 2011 pp. 31 - 45
• Main Authors: Chouteau, Fabien, Ruiz, José F.
• Format: Book Chapter
• Language: English
• Published: Berlin, Heidelberg Springer Berlin Heidelberg
• Series: Lecture Notes in Computer Science
• Subjects: Delay Queue; Multiprocessor System; Mutual Exclusion; Protected Object; Single Processor
• ISBN: 3642213375; 9783642213373
• ISSN: 0302-9743; 1611-3349
• DOI: 10.1007/978-3-642-21338-0_3

New software architectures demand increasing processing power, and multiprocessor hardware platforms are spreading as the answer to achieve the required performance. Embedded real-time systems are also subject to this trend, but in the case of real-time high-integrity systems, the properties of reliability, predictability and analyzability are also paramount. The Ada 2005 language defined a subset of its tasking model, the Ravenscar profile, that provides the basis for the implementation of deterministic and time analyzable applications on top of a streamlined run-time system. This Ravenscar tasking profile, originally designed for single processors, has proven remarkably useful for modelling verifiable real-time monoprocessor systems. The forthcoming Ada 2012 language proposes a simple extension to the Ravenscar profile to support multiprocessor systems using a fully partitioned approach. The implementation of this scheme is simple, and it can be used to develop applications amenable to schedulability analysis. This paper describes the design and implementation of a restricted run time supporting the Ravenscar tasking model on a bare board multiprocessor machine for safety-critical development.