On system models and schedulability analysis for basic single-rate cyclic executives

Despite their industrial relevance, contemporary textbooks do not pay much attention to cyclic executives, if at all. Analysis techniques for these executives are therefore needed.In this paper, we consider the impact of a real-time system model on the schedulability analysis of basic single-rate cyclic executives. Next to the basic real-time scheduling model ${\mathcal{M}^{\text{B}}}$, presented in [1], two other models are considered in this paper, a first refined model ${\mathcal{M}^{\text{R}}}$ that takes the notion of observable event [2] into account and a second model ${\mathcal{M}^{\text{P}}}$ that in addition also considers the single-path code paradigm [3]. Whereas the exact schedulability analysis for ${\mathcal{M}^{\text{B}}}$ turns out to be pessimistic when applied for the refined model ${\mathcal{M}^{\text{R}}}$, the analysis turns out to be optimistic for the second model ${\mathcal{M}^{\text{P}}}$.