Execution Trace Graph of Dataflow Process Networks

The paper introduces and specifies a formalism that provides complete representations of dataflow process network (DPN) program executions, by means of directed acyclic graphs. Such graphs, also known as execution trace graphs (ETG), are composed of nodes representing each action firing and by directed arcs representing the dataflow program execution constraints between two action firings. Action firings are atomic operations that encompass the algorithmic part of the action executions applied to both, the input data and the actor state variables. The paper describes how an ETG can be effectively derived from a dataflow program, specifies the type of dependencies that need to be included, and the processing that need to be applied so that an ETG become capable of representing all the admissible trajectories that dynamic dataflow programs can execute. The paper also describes how some characteristics of the ETG, related to specific implementations of the dataflow program, can be evaluated by means of high-level and architecture-independent executions of the program. Furthermore, some examples are provided showing how the analysis of the ETGs can support efficient explorations, reductions, and optimizations of the design space, providing results in terms of design alternatives, without requiring any partial implementation or reduction of the expressiveness of the original DPN dataflow program.