Compositional Message Sequence Charts (CMSCs) Are Better to Implement Than MSCs

Abstract

Abstract. Communicating Finite States Machines (CFMs) and Message Sequence Graphs (MSC-graphs for short) are two popular specification formalisms for communicating systems. MSC-graphs capture requirements (scenarios), hence they are the starting point of the design process. Implementing an MSC-graph means obtaining an equivalent deadlock-free CFM, since CFMs correspond to distributed messagepassing algorithms. Several partial answers for the implementation have been proposed. E.g., local-choice MSC-graphs form a subclass of deadlockfree CFM: Testing equivalence with some local-choice MSC-graph is thus a partial answer to the implementation problem. Using Compositional MSCs, we propose a new algorithm which captures more implementable models than with MSCs. Furthermore, the size of the implementation is reduced by one exponential.

Replaying Play In and Play Out: Synthesis of Design Models from Scenarios by Learning

“…Case studies: We applied Smyle to the simple negotiation protocol from [13], the continuous update protocol from [14], a protocol being part of USB 1.1 mentioned in [15], and a variant of the ABP. For the first one, Smyle was provided with 6 positive MSCs and performed 9675 membership and 65 user-queries.…”

MSCan – A Tool for Analyzing MSC Specifications

“…To overcome those drawbacks and to be able to specify non finitely generated behavior such as the alternating-bit protocol, compositional high-level MSCs have been introduced by Gunter et al [6]. We would like to stress that, in all aspects, our tool supports this extension, which enjoys many nice properties and increasing popularity [4].…”

Realizability Criteria for Compositional MSC

“…The joint execution behavior of an implementation is obtained by recomposing the instances. We do not consider the unusual implementation with message parameters proposed in [Gen05], which effectively boils down to renaming the messages and shifting the moments of choice. In such an implementation, additional parameters in a request message are sometimes used to fix the choice that should made by the receiver of the request.…”

“…This is caused by the distributed nature of implementations. The best-known phenomenon leading to problems is non-local choice [BAL97], but also other criteria [HJ00, Gen05,MGR05] have been proposed to determine realizability of specifications in practice [MG05]. In this work we develop a formal framework to study such criteria for the MSC extension that is called compositional MSC [GMP03,MM01].…”