Determining Actual Response Time in P-FRP Using Idle-Period Game Board

Abstract

A new, purely functional model of computation, called Priority-based Functional Reactive Programming (P-FRP), has been introduced as a new paradigm for building real-time software. P-FRP allows assignment of static priorities to tasks and guarantees that, when a higher priority task is released, the system will immediately preempt any lower-priority tasks that may be executing at the time. This execution model is different from the classical preemptive model of real-time systems due to the abort nature of preempted tasks. Methods developed for determining actual response time in the preemptive model are not guaranteed to work in P-FRP. In previous work, the gap-enumeration technique has been presented as a viable alternative to simulations for computing actual response time in P-FRP. Unfortunately, this method is difficult to implement due to its use of a Red-Black tree which is not available as a native function in programming languages. Also this method requires a complex logic loop for finding idle periods. In this paper, we present another technique using game-board which is simple to implement and uses native data structures. However, this simplicity comes at a performance cost which has also been analyzed in this paper.