Interface Automata for Shared Memory

Abstract

Interface theories based on Interface Automata (IA) are formalisms for the component-based specification of concurrent systems. Extensions of their basic synchronization mechanism permit the modelling of data, but are studied in more complex settings involving modal transition systems or do not abstract from internal computation. In this article, we show how de Alfaro and Henzinger's original IA theory can be conservatively extended by shared memory data, without sacrificing simplicity or imposing restrictions. Our extension IA for shared Memory (IAM) decorates transitions with pre-and post-conditions over algebraic expressions on shared variables, which are taken into account by IA's notion of component compatibility. Simplicity is preserved as IAM can be embedded into IA and, thus, accurately lifts IA's compatibility concept to shared memory. We also provide a ground semantics for IAM that demonstrates that our abstract handling of data within IA's open systems view is faithful to the standard treatment of data in closed systems.

Interface Automata for Shared Memory

“…This article expands the published extended abstract [16] in multiple ways. First, a detailed introduction to IA and discussion of closely related work on extending IA with data is given here (see Sect.…”

“…We thank the anonymous reviewers and also the reviewers of the extended abstract of this article [16] for their helpful comments and suggestions.…”

“…Thus, it is now possible to specify that a value is preserved or changed by some operation. The setting in [16] is equivalent to the current one if we refrain from unprimed variables in post-conditions. Additionally, this article technically justifies the pruning employed in parallel composition, includes all proofs of our results, and applies our theory to an illustrative example.…”