Semantic mutation testing

This is the Pre-print version of the Article. The official published version can be obtained from the link below - Copyright @ 2011 ElsevierMutation testing is a powerful and flexible test technique. Traditional mutation testing makes a small change to the syntax of a description (usually a program) in order to create a mutant. A test suite is considered to be good if it distinguishes between the original description and all of the (functionally non-equivalent) mutants. These mutants can be seen as representing potential small slips and thus mutation testing aims to produce a test suite that is good at finding such slips. It has also been argued that a test suite that finds such small changes is likely to find larger changes. This paper describes a new approach to mutation testing, called semantic mutation testing. Rather than mutate the description, semantic mutation testing mutates the semantics of the language in which the description is written. The mutations of the semantics of the language represent possible misunderstandings of the description language and thus capture a different class of faults. Since the likely misunderstandings are highly context dependent, this context should be used to determine which semantic mutants should be produced. The approach is illustrated through examples with statecharts and C code. The paper also describes a semantic mutation testing tool for C and the results of experiments that investigated the nature of some semantic mutation operators for C

A gentle transition from Java programming to Web Services using XML-RPC

Exposing students to leading edge vocational areas of relevance such as Web Services can be difficult. We show a lightweight approach by embedding a key component of Web Services within a Level 3 BSc module in Distributed Computing. We present a ready to use collection of lecture slides and student activities based on XML-RPC. In addition we show that this material addresses the central topics in the context of web services as identified by Draganova (2003)

A library for developing real-time and embedded applications in C

Next generation applications will demand more cost-effective programming abstractions to reduce increasing maintenance and development costs. In this context, the article explores the integration of an efficient programming language and high-level real-time programming abstractions. The resulting abstraction is called Embedded Cyber Physical C (ECP-C) and it is useful for designing real-time applications directly on C. The abstraction has its roots on the real-time Java: one of the most modern programming languages, which benefited from mature programming patterns previously developed for other languages. It also targets embedded processors running on limited hardware. ECP-C takes the programming abstractions described in real-time Java and reflects them into a C application system, providing extensions for multi-threading, resource sharing, memory management, external event, signaling, and memory access. It also reports on the performance results obtained in a set of infrastructures used to check ECP-C, providing clues on the overhead introduced by these mechanisms on limited infrastructures. (C) 2015 Elsevier B.V. All rights reserved.This work has been partially funded by Distributed Java Infrastructure for Real-Time Big-Data (CAS14/00118) and by eMadrid: Investigación y Desarrollo de tecnologías educativas en la Comunidad de Madrid (S2013/ICE-2715). This research was supported by the national project REM4VSS (TIN-2011-28339) and by European Union’s 7th Framework Programme Under Grant Agreement FP7-IC6-318763

Dynamic Compilation for Functional Programs

Diese Arbeit behandelt die dynamische, zur Laufzeit stattfindende Übersetzung und Optimierung funktionaler Programme. Ziel der Optimierung ist die erhöhte Laufzeiteffizient der Programme, die durch die compilergesteuerte Eliminierung von Abstraktionen der Programmiersprache erreicht wird. Bei der Implementierung objekt-orientierter Programmiersprachen werden bereits seit mehreren Jahrzehnten Compiler-Techniken zur Laufzeit eingesetzt, um objekt-orientierte Programme effizient ausführen zu können. Spätestens seit der Einführung der Programmiersprache Java und ihres auf einer abstrakten Maschine basierenden Ausführungsmodells hat sich die Praktikabilität dieser Implementierungstechnik gezeigt. Viele Eigenschaften moderner Programmiersprachen konnten erst durch den Einsatz dynamischer Transformationstechniken effizient realisiert werden, wie zum Beispiel das dynamische Nachladen von Programmteilen (auch über Netzwerke), Reflection sowie verschiedene Sicherheitslösungen (z.B. Sandboxing). Ziel dieser Arbeit ist zu zeigen, dass rein funktionale Programmiersprachen auf ähnliche Weise effizient implementiert werden können, und sogar Vorteile gegenüber den allgemein eingesetzten objekt-orientierten Sprachen bieten, was die Effizienz, Sicherheit und Korrektheit von Programmen angeht. Um dieses Ziel zu erreichen, werden in dieser Arbeit Implementierungstechniken entworfen bzw. aus bestehenden Lösungen weiterentwickelt, welche die dynamische Kompilierung und Optimierung funktionaler Programme erlauben: zum einen präsentieren wir eine Programmzwischendarstellung (getypte dynamische Continuation-Passing-Style-Darstellung), welche sich zur dynamischen Kompilierung und Optimierung eignet. Basierend auf dieser Darstellung haben wir eine Erweiterung zur verzögerten und selektiven Codeerzeugung von Programmteilen entwickelt. Der wichtigste Beitrag dieser Arbeit ist die dynamische Spezialisierung zur Eliminierung polymorpher Funktionen und Datenstrukturen, welche die Effizienz funktionaler Programme deutlich steigern kann. Die präsentierten Ergebnisse experimenteller Messungen eines prototypischen Ausführungssystems belegen, dass funktionale Programme effizient dynamisch kompiliert werden können.This thesis is about dynamic translation and optimization of functional programs. The goal of the optimization is increased run-time efficiency, which is obtained by compiler-directed elimination of programming language abstractions. Object-oriented programming languages have been implemented for several decades using run-time compilation techniques. With the introduction of the Java programming language and its virtual machine-based execution model, the practicability of this implementation method for real-world applications has been proved. Many aspects of modern programming languages, such as dynamic loading and linking of code (even across networks), reflection and security solutions (e.g., sandboxing) can be realized efficiently only by using dynamic transformation techniques. The goal of this work is to show that functional programming languages can be efficiently implemented in a similar way, and that these languages even offer advantages when compared to more common object-oriented languages. Efficiency, security and correctness of programs is easier to ensure in the functional setting. Towards this goal, we design and develop implementation techniques to enable dynamic compilation and optimization of functional programming languages: we describe an intermediate representation for functional programs (typed dynamic continuation-passing style), which is well suited for dynamic compilation. Based on this representation, we have developed an extension for incremental and selective code generation. The main contribution of this work shows how dynamic specialization of polymorphic functions and data structures can increase the run-time efficiency of functional programs considerably. We present the results of experimental measurements for a prototypical implementation, which prove that functional programs can efficiently be dynamically compiled

Optimizing scoped and immortal memory management in real-time java

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The Real-Time Specification for Java (RTSJ) introduces a new memory management model which avoids interfering with the garbage collection process and achieves better deterministic behaviour. In addition to the heap memory, two types of memory areas are provided - immortal and scoped. The research presented in this Thesis aims to optimize the use of the scoped and immortal memory model in RTSJ applications. Firstly, it provides an empirical study of the impact of scoped memory on execution time and memory consumption with different data objects allocated in scoped memory areas. It highlights different characteristics for the scoped memory model related to one of the RTSJ implementations (SUN RTS 2.2). Secondly, a new RTSJ case study which integrates scoped and immortal memory techniques to apply different memory models is presented. A simulation tool for a real-time Java application is developed which is the first in the literature that shows scoped memory and immortal memory consumption of an RTSJ application over a period of time. The simulation tool helps developers to choose the most appropriate scoped memory model by monitoring memory consumption and application execution time. The simulation demonstrates that a developer is able to compare and choose the most appropriate scoped memory design model that achieves the least memory footprint. Results showed that the memory design model with a higher number of scopes achieved the least memory footprint. However, the number of scopes per se does not always indicate a satisfactory memory footprint; choosing the right objects/threads to be allocated into scopes is an important factor to be considered. Recommendations and guidelines for developing RTSJ applications which use a scoped memory model are also provided. Finally, monitoring scoped and immortal memory at runtime may help in catching possible memory leaks. The case study with the simulation tool developed showed a space overhead incurred by immortal memory. In this research, dynamic code slicing is also employed as a debugging technique to explore constant increases in immortal memory. Two programming design patterns are presented for decreasing immortal memory overheads generated by specific data structures. Experimental results showed a significant decrease in immortal memory consumption at runtime

Dynamically generated multi-modal application interfaces

This work introduces a new UIMS (User Interface Management System), which aims to solve numerous problems in the field of user-interface development arising from hard-coded use of user interface toolkits. The presented solution is a concrete system architecture based on the abstract ARCH model consisting of an interface abstraction-layer, a dialog definition language called GIML (Generalized Interface Markup Language) and pluggable interface rendering modules. These components form an interface toolkit called GITK (Generalized Interface ToolKit). With the aid of GITK (Generalized Interface ToolKit) one can build an application, without explicitly creating a concrete end-user interface. At runtime GITK can create these interfaces as needed from the abstract specification and run them. Thereby GITK is equipping one application with many interfaces, even kinds of interfaces that did not exist when the application was written. It should be noted that this work will concentrate on providing the base infrastructure for adaptive/adaptable system, and does not aim to deliver a complete solution. This work shows that the proposed solution is a fundamental concept needed to create interfaces for everyone, which can be used everywhere and at any time. This text further discusses the impact of such technology for users and on the various aspects of software systems and their development. The targeted main audience of this work are software developers or people with strong interest in software development

RESTful Web Services Development with a Model-Driven Engineering Approach

A RESTful web service implementation requires following the constrains inherent to Representational State Transfer (REST) architectural style, which, being a non-trivial task, often leads to solutions that do not fulfill those requirements properly. Model-driven techniques have been proposed to improve the development of complex applications. In model-driven software development, software is not implemented manually based on informal descriptions, but partial or completely generated from formal models derived from metamodels. A model driven approach, materialized in a domain specific language that integrates the OpenAPI specification, an emerging standard for describing REST services, allows developers to use a design first approach in the web service development process, focusing in the definition of resources and their relationships, leaving the repetitive code production process to the automation provided by model-driven engineering techniques. This also allows to shift the creative coding process to the resolution of the complex business rules, instead of the tiresome and error-prone create, read, update, and delete operations. The code generation process covers the web service flow, from the establishment and exposure of the endpoints to the definition of database tables.A implementação de serviços web RESTful requer que as restrições inerentes ao estilo arquitetónico “Representational State Transfer” (REST) sejam cumpridas, o que, sendo usualmente uma tarefa não trivial, geralmente leva a soluções que não atendem a esses requisitos adequadamente. Técnicas orientadas a modelos têm sido propostas para melhorar o desenvolvimento de aplicações complexas. No desenvolvimento de software orientado a modelos, o software não é implementado manualmente com base em descrições informais, mas parcial ou completamente gerado a partir de modelos formais derivados de meta-modelos. Uma abordagem orientada a modelos, materializada através de uma linguagem específica do domínio que integra a especificação OpenAPI, um padrão emergente para descrever serviços REST, permite aos desenvolvedores usar uma primeira abordagem de design no processo de desenvolvimento de serviços da Web, concentrando-se na definição dos recursos e das suas relações, deixando o processo de produção de código repetitivo para a automação fornecida por técnicas de engenharia orientadas a modelos. Isso também permite focar o processo de codificação criativo na resolução e implementação das regras de negócios mais complexas, em vez de nas operações mais repetitivas e propensas a erros: criação, leitura, atualização e remoção de dados. O processo de geração de código abrange o fluxo do serviço web desde o estabelecimento e exposição dos caminhos para os serviços disponíveis até à definição de tabelas de base de dados

Abstraction over non-local object information in aspect-oriented programming using path expression pointcuts

Aspect-oriented software development (AOSD) consists of a number of technologies that promise a better level of modularization of concerns that cannot be separated in individual modules by using conventional techniques. Aspect-oriented programming (AOP) is one of these technologies. It allows the modularization at the level of software application code. It provides programmers with means to quantify over specific points in the base application code, called join points, at which the crosscutting concern code must be triggered. The quantification is achieved by special selection constructs called pointcuts, while the triggered code that is responsible for adapting the selected join point is provided by special construct called advice. The selection and adaptation mechanisms in aspect-oriented programming depend heavily on the distinguishing properties of the join points. These properties can either be derived from the local execution context at the join point or they are considered to be non-local to the join point. Aspect-oriented systems provide a plenty of pointcut constructs that support accessing the local join point properties, while they rarely support the non-local properties. A large research effort has been achieved to extend current aspectoriented systems in order to solve the problem of non-locality. However, none of these proposals support the non-local object relationships. There are many situations where a good abstraction over nonlocal object information is needed, otherwise, the developers will be obliged to provide complex and error-prone workarounds inside advice body that conceptually do not reflect the semantics of join point selection and mix it with the semantics of join point daptation. Such recurrent situations occur when trying to modularize the object persistence concern. Object persistence, the process of storing and retrieving objects to and from the datastore, is a classical example of crosscutting concern. Orthogonal object persistence meets the obliviousness property of AOP: The base code should not be prepared upfront for persistence. This thesis addresses the shortcomings in current aspect-oriented persistence systems. It shows that the reason for such shortcomings is due to the lack of supporting non-local object information by the used aspect-oriented languages. To overcome this problem, this thesis proposes a new extension to the current pointcut languages called path expression pointcuts that operate on object graphs and make relevant object information available to the aspects. As an explicit and complete construct, a formal semantics and type system have provided. Moreover, an implementation of path expression pointcuts is discussed in the thesis along with its usage to show how the aforementioned problems are resolved

SWA-KMDLS: An Enhanced e-Learning Management System Using Semantic Web and Knowledge Management Technology

In this era of knowledge economy in which knowledge have become the most precious resource, surveys have shown that e-Learning has been on the increasing trend in various organizations including, among others, education and corporate. The use of e-Learning is not only aim to acquire knowledge but also to maintain competitiveness and advantages for individuals or organizations. However, the early promise of e-Learning has yet to be fully realized, as it has been no more than a handout being published online, coupled with simple multiple-choice quizzes. The emerging of e-Learning 2.0 that is empowered by Web 2.0 technology still hardly overcome common problem such as information overload and poor content aggregation in a highly increasing number of learning objects in an e-Learning Management System (LMS) environment. The aim of this research study is to exploit the Semantic Web (SW) and Knowledge Management (KM) technology; the two emerging and promising technology to enhance the existing LMS. The proposed system is named as Semantic Web Aware-Knowledge Management Driven e-Learning System (SWA-KMDLS). An Ontology approach that is the backbone of SW and KM is introduced for managing knowledge especially from learning object and developing automated question answering system (Aquas) with expert locator in SWA-KMDLS. The METHONTOLOGY methodology is selected to develop the Ontology in this research work. The potential of SW and KM technology is identified in this research finding which will benefit e-Learning developer to develop e-Learning system especially with social constructivist pedagogical approach from the point of view of KM framework and SW environment. The (semi-) automatic ontological knowledge base construction system (SAOKBCS) has contributed to knowledge extraction from learning object semiautomatically whilst the Aquas with expert locator has facilitated knowledge retrieval that encourages knowledge sharing in e-Learning environment. The experiment conducted has shown that the SAOKBCS can extract concept that is the main component of Ontology from text learning object with precision of 86.67%, thus saving the expert time and effort to build Ontology manually. Additionally the experiment on Aquas has shown that more than 80% of users are satisfied with answers provided by the system. The expert locator framework can also improve the performance of Aquas in the future usage. Keywords: semantic web aware – knowledge e-Learning Management System (SWAKMDLS), semi-automatic ontological knowledge base construction system (SAOKBCS), automated question answering system (Aquas), Ontology, expert locator

Adaptable software reuse:binding time aware modelling language to support variations of feature binding time in software product line engineering

Software product line engineering (SPLE) is a paradigm for developing a family of software products from the same reusable assets rather than developing individual products from scratch. In many SPLE approaches, a feature is often used as the key abstraction to distinguish between the members of the product family. Thus, the sets of products in the product line are said to have ’common’ features and differ in ’variable’ features. Consequently, reusable assets are developed with variation points where variant features may be bound for each of the diverse products. Emerging deployment environments and market segments have been fuelling demands for adaptable reusable assets to support additional variations that may be required to increase the usage-context of the products of a product line. Similarly, feature binding time - when a feature is included in a product and made available for use - may vary between the products because of uncertain market conditions or diverse deployment environments. Hence, variations of feature binding time should also be supported to cover the wide-range of usage-contexts. Through the execution of action research, this thesis has established the following: Language-based implementation techniques, that are specifically proposed to implement variations in the form of features, have better modularity but are not better than the existing classical technique in terms of modifiability and do not support variations in feature binding time. Similarly, through a systematic literature review, this thesis has established the following: The different engineering approaches that are proposed to support variations of feature binding time are limited in one of the following ways: a feature may have to be represented/implemented multiple time, each for a specific binding time; The support is only to execution context and therefore limited in scope; The support focuses on too fine-grained model elements or too low-level of abstraction at source-codes. Given the limitations of the existing approaches, this thesis presents binding time aware modelling language that supports variations of feature binding time by design and improves the modifiability of reusable assets of a product line