Interactive Execution Time Predictions using Reference Attributed Grammars

Abstract

A central problem for real-time scheduling is to acquire tight but conservative upper bounds on task execution times. We present a prototype for an environment where such bounds are interactively presented in terms of source code constructs to the programmer during development. The prototype is based on the language development tool APPLAB and uses an extended attribute grammar formalism, reference attributed grammars (RAGs), which overcomes some drawbacks of conventional attribute grammars in this context (e.g. description of non-local dependencies). In this paper we show how timing schemata can be implemented as RAGs. Our experience is that the RAG approach allows timing schemata to be implemented in a clear, concise, and modular manner. 1. Introduction Real-time scheduling algorithms, such as [9], generally assume the worst-case execution time (WCET) of tasks to be known. However, few tools to predict the WCET are available. Without prediction tools, the only way to estima...