A Time-Aware Programming Framework for Constructing Predictable Real-Time Systems

Real-time systems need reliable guarantees for the satisfaction of their timing constraints. However, novel speed-up hardware architectures and software mechanism, which target improving average-case performances, ignore and sometimes worsen the ability to obtain guarantees. An alternative approach is the Logical Execution Time (LET) model, but there are some deficiencies in existing LET-based development tools. In this paper, we propose a novel LET-based time-aware programming framework called TipFrame. The framework introduces Servants to improve the responsiveness of LET-based periodic tasks further. The runtime makes behaviors in the system level consistent with the semantics of LET model for predictability. TipFrame implements in C language providing time-aware programming interfaces called TipFrame-C. The programming paradigm of TipFrame-C is described using an autopilot avionic control system. Evaluation results demonstrate that our approach is effective and efficient to construct LET-based real-time systems.

I. Introduction

Real-time applications in automotive, aviation and industrial automation have to guarantee not only the functionality but also the timeliness of the results. Here, a deadline is associated with those tasks, and a failure to complete before this deadline may lead to catastrophic consequences. Hence, for the correctness of real-time embedded systems, it is essential to verify and validate the temporal behaviors of tasks.