Visualization of scheduling in real-time embedded systems

Abstract

Many embedded systems, especially real-time systems, are used in safety-critical applications such as cars and aircraft. The consequences of different scheduling algorithms for such systems have to be properly understood. Software which simulates scheduling processes supports the research and development of new scheduling policies. It may be used for educational purposes, as simulation and visualization enhance the understanding of the consequences of scheduling decisions. This thesis introduces new, flexible, and extensible discrete event-driven simulation software. The software focuses on but is not limited to scheduling policies primarily used in real-time and embedded systems. Contrary to most existing scheduling simulators, it synchronously simulates and visualizes the current simulation result. In order to inspect the current scheduling situation in closer detail, the software is designed to allow pausing the simulation automatically on the occurrence of specific points of interest or manually at an arbitrary time. The simulation model is specified by a human-readable file which is loaded by the software. During the simulation, elements are added to the simulation model and each element is visualized. The simulation meta-model is designed to support a variety of system configurations. It supports shared resources with several units as well as multiple processing units. A set of scheduling policies and resource access protocols for single-core systems as well as a basic multi-core protocol were implemented and demonstrate the functionality of the software.