On the parameterized algebraic specification of concurrent systems

Abstract

A technique for specifying concurrent systems is shown, that uses the algebraic specification language ASL. A system is algebraically specified as a transition system and a concurrent system is the result of composing systems by three basic operations: synchronization, parallel composition and monitoring. These operations are schematically described using the parameterization concept of ASL and they are in the same time examples for the power of ASL since they cannot be formally specified in other specification languages. Each particular synchronization, parallel composition or monitoring is defined by instantiating on appropriate parameters a unique specification, which produces a transition system out of an input transition system. By combining the three operations we obtain a formal support for a methodology of hierarchical and modular specification of concurrent systems. Moreover it is shown that combining tools for defining semantics in ASL with the above parameterized schema provides a standard way for giving to a concurrent system a variety of semantics depending on observability constraints. Mathematical Foundations of Software Development Mathematical Foundations of Software Development Look Inside Other actions Export citations About this Boo

Labelled transition logic: an outline

“…The outlined approach has been developed since 1984 mainly by the authors, (see [14,12]) with an important contribution of M. Wirsing in the early stages (see [7]); later on other people contributed to some related aspects, notably A. Giovini ( † 93) for the observational semantics [5] and F. Morando for the development of a rapid prototyping system [38,9]. The idea of conditional LTL was the core of [7], where its specifications were called algebraic transition systems; the concept of higher-order concurrency was explored in [14] and its semantics foundations laid down in [3] and generalized in [5].…”

“…The idea of conditional LTL was the core of [7], where its specifications were called algebraic transition systems; the concept of higher-order concurrency was explored in [14] and its semantics foundations laid down in [3] and generalized in [5]. Requirement LT-specifications have been dealt with especially in [33,57,17] and some methodological aspects have been addressed in [18].…”

“…In the past we have also used the names algebraic transition systems (e.g., in [7,14]) and dynamic specifications (e.g., in [33,57,19]) for the same purpose. The purpose of an LT-specification is to define, by an appropriate semantics, LT-structures, or better isomorphism classes of LT-structures (abstract LT-structures).…”

“…For example, in [55] a binary parallel operator gives the structure of a CSP program, although the true concurrent structure is that of an unordered group of processes (i.e., a set); and [44] presents an SOS semantics for a subset of Ada, where the handshaking communication between two tasks (concurrent activity) and the raising of an exception within a task (sequential activity) are modelled in the same way, because there is no way to explicitly distinguish the concurrent and the sequential combinators. Finally, clearly SOS does not provide any means for abstract algebraic specifications; in particular it is not possible to define static axioms, which have been proved so useful and are becoming more and more popular (see [7] for a first appearance and [46] for further strong motivations).…”

A model for distributed systems based on graph rewriting

“…Among others, we could mention Petri nets [32], Hoare's CSP [5, 221, Milner's synchronization trees and asynchronous and synchronous CCS [25, 261, Plotkin's labeled transition systems [33], Astesiano's Structured Monitored Linear Concurrent Systems [ 1,2], Nivat's transition systems [3 11, COSY path expressions by Lauer et al [23], Winkowski's concurrent systems [36], and Winskel's event structures [29,371. One author has recently defined a model called Labeled Event Structures (LES) inspired by nets, synchronization trees, and event structures [7, 271. In this paper we describe Grammars for Distributed Systems (GDS), an operational model for concurrent distributed systems based on graphs and graphrewriting systems.…”