The Dual-Path Code Paradigm for Time-Deterministic and Efficient Networked Embedded Systems

The single-path code paradigm [1] has been conceived to generate real-time code that is highly temporally predicable, making worst-case execution time analysis trivial. The software/hardware architecture proposed in [2], which only supports a time-triggered message interface, builds on the singlepath code paradigm and static scheduling of tasks. The presented execution model in that paper yields software that is time-predictable by construction, and therefore supports timepredictable communication in a networked system. In this paper, we present the dual-path code paradigm that extends the execution model presented in [2]. In particular, this paradigm improves schedulability of an end-system, through the notion of observable event [3], [4], and supports energy efficient scheduling of regularly polling tasks at these end-systems, by exploiting the 1-1 correspondence between (input) events and (output) responses of tasks. The dual-path code paradigm is therefore particularly suitable for the construction of timedeterministic and efficient networked hard real-time embedded systems.