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Design by contract (DbC) is a software development methodology that focuses on clearly defining the interfaces between components to produce better quality object-oriented software. Though there exists ample support for DbC for sequential programs, applying DbC to concurrent programs presents several challenges. Using Java as the target programming language, we tackle such challenges by augmenting the Java Modelling Language (JML) and modifying the JML compiler (jmlc) to generate runtime assertion checking code to support DbC in concurrent programs. We applied our solution in a carefully designed case study on a highly concurrent industrial software system from the telecommunications domain to assess the effectiveness of contracts as test oracles in detecting and diagnosing functional faults in concurrent software. Based on these results, clear and objective requirements are defined for contracts to be effective test oracles for concurrent programs whilst balancing the effort to design them. Effort is measured indirectly through the contract complexity measure (CCM), a measure we define. Main results include that contracts of a realistic level of completeness and complexity can detect around 76 percent of faults and reduce the diagnosis effort for such faults tenfold. We, therefore, show that DbC can be applied to concurrent software and can be a valuable tool to improve the economics of software engineering. [ABSTRACT FROM PUBLISHER]

Unified modelling language (UML) is a visual modelling language, which has gained popularity among software practitioners. In a model‐driven software development environment, the existing UML tools mainly support automatic generation of structural code from UML class diagrams. However, the code generation from UML diagrams such as statechart, activity, collaboration and sequence diagrams (SDs) are not supported by most UML tools and also have scarcely been reported in the literatures. This work proposes an approach to automatic generation of code from UML 2.x SDs of use cases. From the XML metadata interchange (XMI) representation of an SD of a use case, the authors construct a graph model called sequence integration graph (SIG). The SIG encapsulates information related to messages, control flow and method scope of interactions. These information are then used to generate code. The proposed approach has been tested using a number of real‐life application systems and the results substantiate the efficacy of the approach to synthesise the code for controller classes. The authors observe that approximately 48% of the total lines of code within controller class methods can be generated with the proposed approach. The proposed approach can be easily extended to other behavioural UML models such as interaction‐overview diagrams, communication diagrams and activity diagrams. [ABSTRACT FROM AUTHOR]

A component based modeling language with the component interfaces derived from the elements of the Petri net theory called CNet is presented in this paper. In contrast to IEC 61499 function blocks that define the flow of events and data separately, CNet models them combined as colored tokens. The event-discrete behavior of CNet components is described by a special class of colored Petri nets with timed arcs and sharpened semantics in order to allow automatic generation of possibly concurrent Java code. In this paper, the state space of CNet components is analyzed and a novel event-discrete "handler-based" execution model that implicitly models an automaton is introduced. [ABSTRACT FROM PUBLISHER]