Sporadic tasks in hard real-time systems

Abstract

In this paper, we illustrate how systems containing hard real-time sporadic tasks can be analysed for their worst case behaviour. In order to undertake this schedulability analysis, it is necessary to define the minimum inter-arrival time and/or maximum arrival frequency of sporadic tasks. Furthermore, at run-time it is essential to ensure that sporadic tasks are not invoked more often than has been guaranteed by the analysis. We assume that sporadics are invoked by interrupts and that interrupts can be masked under software control.