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Deadline Monotonic Scheduling Theory

1992; Elsevier BV; Volume: 25; Issue: 11 Linguagem: Inglês

10.1016/s1474-6670(17)50124-x

2589-3653

Neil Audsley, Alan Burns, Mike Richardson, Andy Wellings,

Embedded Systems Design Techniques

Scheduling theories are now sufficiently mature that a genuine engineering approach to the construction of hard real-time systems is possible. In this paper we discuss the application of Deadline Monotonie Scheduling Theory (DMST). This theory is an extension of the more familiar approach based on rate monotonie priority assignment. The model presented can accommodate periodic and sporadic processes, different levels of criticality, process mteracuon and blocking, precedence constrained processes and multi-deadline processes. It is particularly well integrated with the use of Immediate Priority Ceiling Inheritance for control over process blocking. A basic pseudo-polynomial schedulability test is outlined and then supplemented by the introduction of offsets to control jitter, and period transformation to enable critical (hard) processes to be “protected” during potential transient overloads. These mathematical techniques derived within DMST can help designers experiment with altemauve formulations and prove essenual properties of systems before they arc deployed.