UTP, Circus, and Isabelle

We dedicate this paper with great respect and friendship to He Jifeng on the occasion of his 80th birthday. Our research group owes much to him. The authors have over 150 publications on unifying theories of programming (UTP), a research topic Jifeng created with Tony Hoare. Our objective is to recount the history of Circus (a combination of Z, CSP, Dijkstra’s guarded command language, and Morgan’s refinement calculus) and the development of Isabelle/UTP. Our paper is in two parts. (1) We first discuss the activities needed to model systems: we need to formalise data models and their behaviours. We survey our work on these two aspects in the context of Circus. (2) Secondly, we describe our practical implementation of UTP in Isabelle/HOL. Mechanising UTP theories is the basis of novel verification tools. We also discuss ongoing and future work related to (1) and (2). Many colleagues have contributed to these works, and we acknowledge their support

Twinning Automata and Regular Expressions for String Static Analysis

In this paper we formalize Tarsis, a new abstract domain based on the abstract interpretation theory that approximates string values through finite state automata. The main novelty of Tarsis is that it works over an alphabet of strings instead of single characters. On the one hand, such an approach requires a more complex and refined definition of the widening operator, and the abstract semantics of string operators. On the other hand, it is in position to obtain strictly more precise results than state-of-the-art approaches. We implemented a prototype of Tarsis, and we applied it to some case studies taken from some of the most popular Java libraries manipulating string values. The experimental results confirm that Tarsis is in position to obtain strictly more precise results than existing analyses

Ernst Denert Award for Software Engineering 2019

This open access book provides an overview of the dissertations of the five nominees for the Ernst Denert Award for Software Engineering in 2019. The prize, kindly sponsored by the Gerlind & Ernst Denert Stiftung, is awarded for excellent work within the discipline of Software Engineering, which includes methods, tools and procedures for better and efficient development of high quality software. An essential requirement for the nominated work is its applicability and usability in industrial practice. The book contains five papers describing the works by Sebastian Baltes (U Trier) on Software Developers’Work Habits and Expertise, Timo Greifenberg’s thesis on Artefaktbasierte Analyse modellgetriebener Softwareentwicklungsprojekte, Marco Konersmann’s (U Duisburg-Essen) work on Explicitly Integrated Architecture, Marija Selakovic’s (TU Darmstadt) research about Actionable Program Analyses for Improving Software Performance, and Johannes Späth’s (Paderborn U) thesis on Synchronized Pushdown Systems for Pointer and Data-Flow Analysis – which actually won the award. The chapters describe key findings of the respective works, show their relevance and applicability to practice and industrial software engineering projects, and provide additional information and findings that have only been discovered afterwards, e.g. when applying the results in industry. This way, the book is not only interesting to other researchers, but also to industrial software professionals who would like to learn about the application of state-of-the-art methods in their daily work

Faculty Publications and Creative Works 2005

Faculty Publications & Creative Works is an annual compendium of scholarly and creative activities of University of New Mexico faculty during the noted calendar year. Published by the Office of the Vice President for Research and Economic Development, it serves to illustrate the robust and active intellectual pursuits conducted by the faculty in support of teaching and research at UNM. In 2005, UNM faculty produced over 1,887 works, including 1,887 scholarly papers and articles, 57 books, 127 book chapters, 58 reviews, 68 creative works and 4 patented works. We are proud of the accomplishments of our faculty which are in part reflected in this book, which illustrates the diversity of intellectual pursuits in support of research and education at the University of New Mexico

Concurrency and static analysis

The thesis describes three important contributions developed during my doctoral course, all involving the use and the verification of concurrent Java code: Binary decision diagrams, or BDDs, are data structures for the representation of Boolean functions. These functions are of great importance in many fields. It turns out that BDDs are the state-of-the-art representation for Boolean functions, and indeed all real world applications use a BDD library to represent and manipulate Boolean functions. It can be desirable to perform Boolean operations from different threads at the same time. In order to do this, the BDD library in use must allow threads to access BDD data safely, avoiding race conditions. We developed a Java BDD library, that is fast in both single and multi-threaded applications, that we use in the Julia static program analyzer. We defined a sound static analysis that identifies if and where a Java bytecode program lets data flow from tainted user input (including servlet requests) into critical operations that might give rise to injections. Data flow is a prerequisite to injections, but the user of the analysis must later gage the actual risk of the flow. Namely, analysis approximations might lead to false alarms and proper input validation might make actual flows harmless. Our analysis works by translating Java bytecode into Boolean formulas that express all possible explicit flows of tainted data. The choice of Java bytecode simplifies the semantics and its abstraction (many high-level constructs must not be explicitly considered) and lets us analyze programs whose source code is not available, as is typically the case in industrial contexts that use software developed by third parties, such as banks. The standard approach to prevent data races is to follow a locking discipline while accessing shared data: always hold a given lock when accessing a given shared datum. It is all too easy for a programmer to violate the locking discipline. Therefore, tools are desirable for formally expressing the locking discipline and for verifying adherence to it. The book Java Concurrency in Practice (JCIP) proposed the @GuardedBy annotation to express a locking discipline. The original @GuardedBy annotation was designed for simple intra-class synchronization policy declaration. @GuardedBy fields and methods are supposed to be accessed only when holding the appropriate lock, referenced by another field, in the body of the class (or this). In simple cases, a quick visual inspection of the class code performed by the programmer is sufficient to verify the synchronization policy correctness. However, when we think deeper about the meaning of this annotation, and when we try to check and infer it, some ambiguities rise. Given these ambiguities of the specification for @GuardedBy, different tools interpret it in different ways. Moreover, it does not prevent data races, thus not satisfying its design goals. We provide a formal specification that satisfies its design goals and prevents data races. We have also implemented our specification in the Julia analyzer, that uses abstract interpretation to infer valid @GuardedBy annotations for unannotated programs. It is not the goal of this implementation to detect data races or give a guarantee that they do not exist. Julia determines what locking discipline a program uses, without judging whether the discipline is too strict or too lax for some particular purpose

Políticas de Copyright de Publicações Científicas em Repositórios Institucionais: O Caso do INESC TEC

A progressiva transformação das práticas científicas, impulsionada pelo desenvolvimento das novas Tecnologias de Informação e Comunicação (TIC), têm possibilitado aumentar o acesso à informação, caminhando gradualmente para uma abertura do ciclo de pesquisa. Isto permitirá resolver a longo prazo uma adversidade que se tem colocado aos investigadores, que passa pela existência de barreiras que limitam as condições de acesso, sejam estas geográficas ou financeiras. Apesar da produção científica ser dominada, maioritariamente, por grandes editoras comerciais, estando sujeita às regras por estas impostas, o Movimento do Acesso Aberto cuja primeira declaração pública, a Declaração de Budapeste (BOAI), é de 2002, vem propor alterações significativas que beneficiam os autores e os leitores. Este Movimento vem a ganhar importância em Portugal desde 2003, com a constituição do primeiro repositório institucional a nível nacional. Os repositórios institucionais surgiram como uma ferramenta de divulgação da produção científica de uma instituição, com o intuito de permitir abrir aos resultados da investigação, quer antes da publicação e do próprio processo de arbitragem (preprint), quer depois (postprint), e, consequentemente, aumentar a visibilidade do trabalho desenvolvido por um investigador e a respetiva instituição. O estudo apresentado, que passou por uma análise das políticas de copyright das publicações científicas mais relevantes do INESC TEC, permitiu não só perceber que as editoras adotam cada vez mais políticas que possibilitam o auto-arquivo das publicações em repositórios institucionais, como também que existe todo um trabalho de sensibilização a percorrer, não só para os investigadores, como para a instituição e toda a sociedade. A produção de um conjunto de recomendações, que passam pela implementação de uma política institucional que incentive o auto-arquivo das publicações desenvolvidas no âmbito institucional no repositório, serve como mote para uma maior valorização da produção científica do INESC TEC.The progressive transformation of scientific practices, driven by the development of new Information and Communication Technologies (ICT), which made it possible to increase access to information, gradually moving towards an opening of the research cycle. This opening makes it possible to resolve, in the long term, the adversity that has been placed on researchers, which involves the existence of barriers that limit access conditions, whether geographical or financial. Although large commercial publishers predominantly dominate scientific production and subject it to the rules imposed by them, the Open Access movement whose first public declaration, the Budapest Declaration (BOAI), was in 2002, proposes significant changes that benefit the authors and the readers. This Movement has gained importance in Portugal since 2003, with the constitution of the first institutional repository at the national level. Institutional repositories have emerged as a tool for disseminating the scientific production of an institution to open the results of the research, both before publication and the preprint process and postprint, increase the visibility of work done by an investigator and his or her institution. The present study, which underwent an analysis of the copyright policies of INESC TEC most relevant scientific publications, allowed not only to realize that publishers are increasingly adopting policies that make it possible to self-archive publications in institutional repositories, all the work of raising awareness, not only for researchers but also for the institution and the whole society. The production of a set of recommendations, which go through the implementation of an institutional policy that encourages the self-archiving of the publications developed in the institutional scope in the repository, serves as a motto for a greater appreciation of the scientific production of INESC TEC

Mathematics in Software Reliability and Quality Assurance

This monograph concerns the mathematical aspects of software reliability and quality assurance and consists of 11 technical papers in this emerging area. Included are the latest research results related to formal methods and design, automatic software testing, software verification and validation, coalgebra theory, automata theory, hybrid system and software reliability modeling and assessment