Schedulability criteria for age constraint processes in hard real-time systems

Real-time systems not only require the semantical correctness of their operations but also the availability of the computational results within some predefined time intervals. Static hard realtime scheduling has to construct an off-line schedule by interleaving all the required computations in a way that the application's time bounds are met. Processes are responsible to carry out the different computations. Depending on the application specific context they have to complete in time due to periodic contraints or age constraints. The paper presents two criteria for the existence of static schedules for sets of real-time processes and assesses their practical relevance in the scope of program development for real-time systems. This approach is based on a transformation from age constraint processes to periodic processes and derives a least upper bounds for the achievable load for age constraint processes is derived. (orig.)Available from TIB Hannover: RO 6844(1998,9) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman