Data optimizations for constraint automata

Abstract

Abstract. Constraint automata (CA) constitute a coordination model based on finite automata on infinite words. Originally introduced for modeling of coordinators, an interesting new application of CAs is implementing coordinators (i.e., compiling CAs into executable code). Such an approach guarantees correctness-by-construction and can even yield code that outperforms hand-crafted code. The extent to which these two potential advantages materialize depends on the smartness of CA-compilers and the existence of proofs of their correctness.Every transition in a CA is labeled by a "data constraint" that specifies an atomic data-flow between coordinated processes as a first-order formula. At run-time, compiler-generated code must handle data constraints as efficiently as possible. In this paper, we present, and prove the correctness of two optimization techniques for CA-compilers related to handling of data constraints: a reduction to eliminate redundant variables and a translation from (declarative) data constraints to (imperative) data commands expressed in a small sequential language. Through experiments, we show that these optimization techniques can have a positive impact on performance of generated executable code.

Treo: Textual Syntax for Reo Connectors

“…Jongmans et al have shown by benchmarks that compiling Reo specifications can produce executable code whose performance competes with or even beats that of hand-crafted programs written in languages such as C or Java using conventional concurrency constructs [18,14,16,15,17]. A textual syntax for Reo that preserves its declarative, compositional nature, allows user-defined primitives, and faithfully complies with the semantics of its nodes can significantly facilitate the uptake of Reo for specification of protocols in large-scale practical applications.…”