Response Time Analysis of the Abort-and-Restart Model under Symmetric Multiprocessing

The Priority-Based Functional Reactive Programming (P-FRP) paradigm, aims to improve the programming of embedded microcontrollers. The combination of purely functional programming and cleanly-abortable event handlers, communicating via transactional memory (TM), makes it possible to write programs as stateless collections of functions, thus making them amenable to proofs and type safety. P-FRP implements executions as function evaluations, therefore, there are no "incomplete" function evaluations, as in the case of a task's interruption. To use P-FRP in the SMP (Symmetric Multiprocessor) environment, we must first understand the response time of programs written in its anticipated multiprocessor extension. Therefore, the contribution of this paper is the response time analysis for the Abort-and-Restart (ANR) event handler semantics of P-FRP for SMP Real-Time systems. ANR is neither a synchronization protocol nor a true scheduling policy. Instead, it is a policy for running tasks where the most important task is scheduled first. Results are derived for both fixed-priority (i.e., Rate Monotonic) and dynamic-priority (i.e., Earliest Deadline First) scheduling. We can say that the Abort-and-Restart and the TM models are similar, but also distinct, thus allowing our results to be adaptable for the analysis of TM.