Realizing live sequence charts in SystemVerilog.

The design of an embedded control system starts with an investigation of properties and behaviors of the process evolving within its environment, and an analysis of the requirement for its safety performance. In early stages, system requirements are often specified as scenarios of behavior using sequence charts for different use cases. This specification must be precise, intuitive and expressive enough to capture different aspects of embedded control systems. As a rather rich and useful extension to the classical message sequence charts, live sequence charts (LSC), which provide a rich collection of constructs for specifying both possible and mandatory behaviors, are very suitable for designing an embedded control system. However, it is not a trivial task to realize a high-level design model in executable program codes effectively and correctly. This paper tackles the challenging task by providing a mapping algorithm to automatically synthesize SystemVerilog programs from given LSC specifications

Automatic Generation of Valid Behavioral Scripts from UML Sequence Diagrams

This paper presents the extension of a UML and OCL tool that enables the textual specification of UML sequence diagrams, and the automated generation of all valid behaviors according to these sequence diagrams. Message Sequence Charts (MSC) are used as the textual notation to specify the UML sequence diagrams, and the USE high-level action language SOIL is used to specify behavior.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto PGC2018-094905-B-I0

Scenario Realizability with Constraint Optimization

International audienceThis work considers implementation of requirements expressed as High-level Message Sequence Charts (HMSCs). All HMSCs are not implementable, but a particular subclass called local HMSCs can be implemented using a simple projection operation. This paper proposes a new technique to transform an arbitrary HMSC specification into a local HMSC, hence allowing implementation. We show that this transformation can be automated as a constraint optimization problem. The impact of modifications brought to the original specification can be minimized w.r.t. a cost function. The approach was evaluated on a large number of randomly generated HMSCs. The results show an average runtime of a few seconds, which demonstrates applicability of the technique

Asynchronous Multiparty Session Type Implementability is Decidable - Lessons Learned from Message Sequence Charts

Multiparty session types (MSTs) provide efficient means to specify and verify asynchronous message-passing systems. For a global type, which specifies all interactions between roles in a system, the implementability problem asks whether there are local specifications for all roles such that their composition is deadlock-free and generates precisely the specified executions. Decidability of the implementability problem is an open question. We answer it positively for global types with sender-driven choice, which allow a sender to send to different receivers upon branching and a receiver to receive from different senders. To achieve this, we generalise results from the domain of high-level message sequence charts (HMSCs). This connection also allows us to comprehensively investigate how HMSC techniques can be adapted to the MST setting. This comprises techniques to make the problem algorithmically more tractable as well as a variant of implementability that may open new design space for MSTs. Inspired by potential performance benefits, we introduce a generalisation of the implementability problem that we, unfortunately, prove to be undecidable

Scenario realizability with constraint optimization

This work considers implementation of requirements expressed as High-level Message Sequence Charts (HMSCs). All HMSCs are not implementable, and the question of whether an HMSC speci cation can be implemented by communicating machines is undecidable in general. However, several subclasses such as local HMSCs can be implemented using a simple projection operation. This paper proposes a new technique to transform an arbitrary HMSC speci cation into a local HMSC, hence allowing implementation.We show that this transformation can be automated as a constraint optimization problem. The impact of modi cations brought to the original speci cation can be minimized w.r.t. a cost function. The approach was evaluated on a large number of randomly generated HMSCs. The results of this experimentation are presented and analyzed. In particular, the evaluation shows an average runtime of a few seconds, which demonstrates applicability of the technique

The Oracle Problem When Testing from MSCs

Message Sequence Charts (MSCs) form a popular language in which scenario-based specifications and models can be written. There has been significant interest in automating aspects of testing from MSCs. This paper concerns the Oracle Problem, in which we have an observation made in testing and wish to know whether this is consistent with the specification. We assume that there is an MSC specification and consider the case where we have entirely independent local testers (local observability) and where the observations of the local testers are logged and brought together (tester observability). It transpires that under local observability the Oracle Problem can be solved in low-order polynomial time if we use sequencing, loops and choices but becomes NP-complete if we also allow parallel components; if we place a bound on the number of parallel components then it again can be solved in polynomial time. For tester observability, the problem is NP-complete when we have either loops or choices. However, it can be solved in low-order polynomial time if we have only one loop, no choices, and no parallel components. If we allow parallel components then the Oracle Problem is NP-complete for tester observability even if we restrict to the case where there are at most two processes