TDE: A time driven engine for predictable execution of realtime systems

Abstract

One of the most important qualities of run-time supports for realtime systems is predictability. The knowledge of behavior and execution time of a system is necessary to define feasible and dependable real-time scheduling. Often real-time operating systems are based on concurrency models that are intrinsically not suitable for real-time execution since timing remains external to the execution model. This approach imposes a translation of time constraints to perform realtime executions. TDE bases the execution of tasks directly on their time constraints. This approach allows the system designer to concentrate on timing issues, and the run-time support to constantly control the system behavior according to timed plans. TDE has been integrated with a commercial real-time operating system. This paper presents the concepts behind TDE and describes the architecture of the implementation.