A Reactive and Adaptive Data Flow Model for Network-of-System Specification

With embedded systems being increasingly networked, appropriate models of computation and communication are needed for specification of such networks-of-systems. Traditional dataflow models have shown their usefulness in analyzing isolated systems. However, these models cannot express the inherent requirements of connected applications, such as dynamic behavior associated with network losses and reactivity to external events. This letter proposes a reactive and adaptive data flow (RADF) model that introduces a notion of empty tokens to expose network losses and provide adaptivity at the application level while maintaining overall determinism. Empty tokens, combined with expanded actor semantics, are also used to model reactivity to sporadic external events. We formally define RADF semantics and show efficient methods for analyzing RADF graphs in terms of their worst-case throughput and latency.