Title: Utilisation bounds of P-FRP tasks

Authors: Chaitanya Belwal; Yuanfeng Wen; Albert M.K. Cheng

Addresses: Department of Computer Science, University of Houston, 501 Philip G. Hoffman Hall, Houston, TX 77204-3010, USA ' Department of Computer Science, University of Houston, 501 Philip G. Hoffman Hall, Houston, TX 77204-3010, USA ' Department of Computer Science, University of Houston, 501 Philip G. Hoffman Hall, Houston, TX 77204-3010, USA

Abstract: Priority-based functional reactive programming (P-FRP) is a new functional programming formalism for developing safety-critical embedded systems. P-FRP allows static priority assignment and guarantees real-time response by preempting lower priority tasks. Due to the state-less nature of functional programmes, preempted tasks in P-FRP are aborted and have to restart after the higher priority tasks have completed execution. Since the execution semantics of P-FRP are different from the classical preemptive model of execution, existing utilisation-based sufficient conditions cannot be applied. In this paper, we derive a new utilisation-based sufficient schedulability condition for P-FRP, and validate it using experimental task sets. We then compare the sufficient schedulability condition of P-FRP with that of the preemptive model to demonstrate the severe restrictions on task set sizes in P-FRP. Effect on the utilisation bound under conditional preemption has also been analysed.

Keywords: schedulability analysis; functional programming; sufficient test; utilisation bound; worst-case response time; WCRT; priority-based FRP; functional reactive programming; P-FRP; safety-critical embedded systems.

DOI: 10.1504/IJES.2014.060918

International Journal of Embedded Systems, 2014 Vol.6 No.1, pp.61 - 72

Accepted: 11 Aug 2013
Published online: 31 Jul 2014 *

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