Abstract

Abstract

Abstract
Real-Time For the Masses (RTFM) is a set of languages and tools being developed to facilitate embedded software development and provide highly efficient implementations geared to static verification. The RTFM-kernel is an architecture designed to provide highly efficient and predicable Stack Resource Policy based scheduling, targeting bare metal (singlecore) platforms. We contribute beyond prior work by introducing a platform independent timer abstraction that relies on existing RTFM-kernel primitives. We develop two alternative implementations for the ARM Cortex-M family of MCUs: a generic implementation, using the ARM defined SysTick- /DWT hardware; and a target specific implementation, using the match compare/free running timers. While sacrificing generality, the latter is more exible and may reduce overall overhead. Invariants for correctness are presented, and methods to static and run-time verification are discussed. Overhead is bound and characterized. In both cases the critical section from release time to dispatch is less than 2us on a 100MHz MCU. Queue and timer mechanisms are directly implemented in the RTFM-core language and can be included in system-wide scheduling analysis.

Abstract

Abstract
The first session of the 18th International Real Time Ada Workshop discussed two aspects of parallel programming in real-time systems, the use of executors in parallel systems, and syntax to guide the reduction of parallel computations to return a correct single answer. This report captures the discussions held and the decisions and recommendations of the workshop on these topics.

Abstract
The main goals of this conference session was to present an overview of a model for fine-grained parallelism in Ada based on the notion of tasklets. The session presented and discussed a general execution model that would support parallelism constructs being considered for possible inclusion in a future version of the Ada standard. The session also presented and discussed a real-time model that provided consistency with the general model while providing enough flexibility to accommodate a wide range of real-time systems with the intent supporting real-time analysis and maintaining or improving the safety features of the language.