Abstract

This paper investigates schedulability tests for mixtures of periodic and aperiodic processes. Following an introduction outlining the constraints associated with rate-monotonic scheduling new schedulability tests are presented for deadline-monotonic scheduling. These apply to collections of periodic processes which have periods not necessarily equal to their deadlines (as is the case for rate-monotonic scheduling). The introduction of aperiodic (sporadic) processes can be catered for in the rate-monotonic scheme by the use of sporadic servers. Restrictions on this method are investigated and a new model based on deadline-monotonic scheduling is described. This model has the property that any mixture of sporadic and periodic process deadlines can be guaranteed (subject to passing an appropriate schedulability test).

Citations

2570	Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment - Liu, Layland - 1973
744	Priority inheritance protocols: an approach to real-time synchronization - Sha, Rajkumar, et al. - 1990
525	The Rate Monotonic Scheduling Algorithm: Exact Characterization and Average Case Behavior - Lehoczky, Sha, et al. - 1989
296	Aperiodic task scheduling for hard real-time systems - Sprunt, Sha, et al. - 1989
289	On the complexity of fixed-priority scheduling of periodic, real-time tasks - JYT, Whitehead - 1982
183	Enhanced aperiodic responsiveness in hard real-time environments - Lehoczky, Sha, et al. - 1987
112	Real-Time Systems and their Programming Languages - Burns, Wellings - 1990
106	Misconceptions about real-time computing: A serious problem for next-generation systems - Stankovic - 1988
105	Real-time scheduling theory and Ada - SHA, B - 1990
20	Weaklyhard real-time systems - Bernat, Burns, et al.