Formal development of Java based Web parallel applications

Formal software development begins with formal specification of the user requirements or design of a system. Hence, formal specification languages are used to resolve ambiguities in user requirements or detect design errors at the early software life cycle. Furthermore, specification-based functional testing derives test inputs from its formal specification. However, formal specifications are expressed using set theory or predicate logics which are non-executable. Thus, functional test execution over abstract expressions would be impossible. Therefore, there is a need to refine abstract specification into a form that can be executable. In this paper, an automatic functional testing framework using object constraint language (OCL) formal specification has been proposed. The major objective of this paper is to describe how the refinement processes are integrated into the specification-based testing framework.

Welcome to the 2007 International Conference on the Principles and Practice of Programming in Java (PPPJ 2007). Thank you for attending, on behalf of the Organizing and Steering Committees. The PPPJ conference is an excellent forum for presentation of research results and discussion of issues related to the Java platform and language. This year, 58 papers were submitted for consideration by the conference. After careful review by the Program Committee members and other reviewers, the Committee accepted 19 full papers and 5 short papers. The topics covered by the papers include a broad range of subjects, i.e., virtual machines, compilation, language design, internet programming, software engineering, generative programming, and Java applications.

There is an extensive literature about refactorings of object-oriented programs, and many refactoring tools for the Java programming language. However, except for a few studies, in practice it is difficult to find precise formal specifications of the preconditions and mechanisms of automated refactorings. Moreover, there is usually no formal proof that a refactoring is correct, i.e., that it preserves the behavior of the program. We present an equational semantics based approach to Java refactoring. Specifically, we use an executable Java formal semantics in the Maude language to: (i) formally specify three useful Java refactorings; and (ii) give detailed proofs of correctness for two of those refactorings, showing that they are behavior-preserving transformations. Besides the obvious benefits of providing rigorous specifications for refactoring tool builders and rigorous correctness guarantees, our approach has the additional advantage of its executability: our formal refactoring specifications can be used directly to refactor Java programs and yield a provably correct Java refactoring tool.

The design of an electronic funds-transfer (EFT) system, using the UNITY parallel programming methodology, is presented. The process begins with a high-level specification that captures the essence of transaction processing in the system. In a series of refinement steps, this specification is transformed into one that leads directly to a program suitable for execution on the distributed architecture of the EFT system. Each refinement step involves replacing a data structure by a distributed version that can be implemented efficiently on the target architecture. By defining a correspondence between the replaced data structure and its distributed counterpart, it can be demonstrated formally that each refinement step preserves the intent of the original specification.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The problem addressed in this paper is the following: how to use high-level Petri nets for the reverse engineering of implemented distributed applications. The paper presents a reverse engineering methodology applied on a real (simple) Java applet based client/server application. First, starting from the Java program, several abstraction steps are described using the CO-OPN/2 formal specification language. Then, the paper presents brand new research that studies property preservations during the refinement process.

An integrated methodology for knowledge-based system development

Software for mission-critical systems is sometimes analysed using formal specification to increase the chances of the system behaving as intended. When sufficient insights into the system have been obtained from the formal analysis, the formal specification is realised in the form of a software implementation. One way to realise the system's software is by automatically generating it from the formal specification -- a technique referred to as code generation. However, in general it is difficult to make guarantees about the correctness of the generated code -- especially while requiring automation of the steps involved in realising the formal specification. This PhD dissertation investigates ways to improve the automation of the steps involved in realising and validating a system based on a formal specification. The approach aims to develop properly designed software tools which support the integration of formal methods tools into the software development life cycle, and which leverage the formal specification in the subsequent validation of the system. The tools developed use a new code generation infrastructure that has been built as part of this PhD project and implemented in the Overture tool -- a formal methods tool that supports the Vienna Development Method. The development of the code generation infrastructure has involved the re-design of the software architecture of Overture. The new architecture brings forth the reuse and extensibility features of Overture to take into account the needs and requirements of software extensions targeting Overture. The tools developed in this PhD project have successfully supported three case studies from externally funded projects. The feedback received from the case study work has further helped improve the code generation infrastructure and the tools built using it.

The popular slogan “write once, run anywhere” effectively renders the expressive capabilities of the JAVA programming framework for developing, deploying, and reusing target-independent applets. Its generality and simplicity has driven most attention of the compiler technology community to developing just-in-time and runtime compilation techniques, local and compositional optimization algorithms. When it comes to real-time JAVA and to the implementation of embedded software, this approach is however far from satisfactory, especially in hard real-time system design (e.g. airborne systems) where conformance to real-time specifications is critical. We show that synchronous design tools, and particularly the design workbench POLYCHRONI, allow for a complete modeling of embedded software written in a high-level and general purpose programming language such as JAVA. The synchronous approach provides a formal engineering model and methodology, using global transformation and optimization techniques, that allow for a JAVA program written once to be mapped on any distributed target architecture. We present a technique to import a resource constrained, multi-threaded, RT JAVA program, together with its runtime system API, into POLYCHRONI. We put this modeling technique to work by considering a formal, refinement-based, design methodology that allows for a correct by construction remapping of the initial threading architecture of a given JAVA program on either a single-threaded target or a distributed architecture. This technique allows to generate stand-alone (Jvm-less) executables and to remap threads onto a given distributed architecture or a prescribed target real-time operating system. As a result, it allows for a complete separation between the virtual threading architecture of the functional-level system design (in JAVA) and its actual, real-time and resource constrained implementation.

Clean room software engineering is a formal software development method that can strictly engineer software development and eliminate defects before they can cause serious harm. The clean room software engineering model has its own advantages and disadvantages in use. To use it in traditional software engineering, it is necessary to clarify the relationship between it and traditional software engineering methods and practices. Based on the technology and principles of the clean room software process, this paper gets the advantages and disadvantages of the clean room. Corresponding the traditional method-based software process to the key technology of the clean room, making the traditional management-based software engineering method and the tailored clean room compatible, and the software engineering practice of the clean room software process is compared with the traditional software engineering practice. To discuss the clean room and traditional software engineering, in order to expand the use of clean room methods, improve the clean room software process, and improve the quality of software.

Telecommunication applications integrate more and more functionalities, and a huge capacity of memory is required; as a result power consumption increases and battery lifetime becomes a serious limitation. An other consequence is that the time to realize such systems becomes too long! This paper presents methods to optimize consumption/time for HW/SW codesign. Then, a refinement step is executed to optimize the schedulings by applying the Dynamic Voltage Scaling/ Dynamic Frequency Scaling technique (DVS/DFS), and founding the best distribution of data between internal memory and external memory in order to decrease the global consumption. The novelty of our work consists in taking into account the consumption parameter during the allocation and scheduling steps; refining the scheduling by exploiting the DVS technique; optimizing the system memory consumption by improving the data storage in internal memory of the processor.KeywordsPower OptimizationExternal MemoryInternal MemoryDesign Space ExplorationDynamic Voltage ScalingThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Modern programs make extensive use of reusable software libraries. For example, a study of a number of large Java applications shows that between 17% and 30% of the classes in those applications use container classes defined in the java.util package. Given this extensive code reuse in Java programs, it is important for the interfaces of reusable classes to be well documented. An interface is well documented if it satisfies the following requirements: (1) the documentation completely describes how to use the interface; (2) the documentation is clear; (3) the documentation is unambiguous; and (4) any deviation between the documentation and the code is machine detectable. Unfortunately, documentation in natural language, which is the norm, does not satisfy the above requirements. Formal specifications can satisfy them but they are difficult to develop, requiring significant effort on the part of programmers. To address the practical difficulties with formal specifications, we describe and evaluate a tool to help programmers write and debug algebraic specifications. Given an algebraic specification of a class, our interpreter generates a prototype that can be used within an application like a regular Java class. When running an application that uses the prototype, the interpreter prints error messages that tell the developer in which way the specification is incomplete or inconsistent with a hand-coded implementation of the class. We use case studies to demonstrate the usefulness of our system.

This work investigates the application of deductive verification techniques to safety critical Java programs, in particular RTSJ programs. A focus is put on the formalization of the RTSJ memory model in dynamic logic, the utilization of a region-based memory model for ensuring non-interference and a design-by-contract based approach for the formal specification and verification of worst case memory consumption.

Fine grained data distributions are widely used to balance computational loads across compute processes in parallel scientific applications. When a fine grained data distribution is used in memory, performance of I/O intensive applications can be limited not only by disk speed but also by message passing, because a large number of small messages may be generated by the implementation strategy used in the underlying parallel file system or parallel I/O library. Combining (or packetizing) a set of small messages into a large message is generally known to speed up parallel I/O. However, overall I/O performance is affected not only by small messages but also by other factors like cyclic block size and interconnect characteristics. We describe small message combination and communication scheduling for fine grained data distributions in the Panda parallel I/O library and analyze I/O performance on parallel platforms having different interconnects: IBM SP2, IBM workstation cluster connected by FDDI and Pentium II cluster connected by Myrinet.

On Formal Specification of Software Components and Systems

As a practice-oriented discipline, Software Engineering (SE) is most effectively taught by using a variety of hands-on experiences. Team-based projects where students can practice their technical and soft skills are a key feature of many software engineering courses aimed to prepare students for the realities of industrial software development. Current research indicates that projects offered in SE courses should have a close connection to the real world, be large scale and complex. On the one hand, students should be able to relate to the requirements and understand them without spending much time acquiring domain knowledge. On the other hand, students should be exposed to changing and evolving requirements, which is one of the main challenges of real-world software projects. Software projects should be large enough and have enough features to engage all members of the student team while enabling them to practice some degree of specialization and experience the advantages and challenges of teamwork. Software projects should be rich enough to allow students practice all previously acquired SE concepts, bring together knowledge from other specialized CS disciplines, and apply a number of modern tools and technologies. One of the most effective ways to learn SE is to expose students to an environment that resembles an industrial setting as much as possible. As a part of an academic program, SE courses can achieve this objective by offering students a balanced combination of three components: teamwork involving up-to-date technology grounded in a solid theoretical foundation . Instructors in SE courses are uniquely positioned to help maintain this balance by simultaneously playing four roles described below. As a customer who contracts a student team to implement a particular project, the instructor may provide a verbal or written description of the project. It is the students? responsibility to conduct the requirements elicitation interviews and to prepare formal requirements specification for subsequent validation with the customer and possible adjustment. The instructor may act as a customer during the acceptance testing throughout the project to make sure that the team is on the right track at every iteration of the project. The instructor acting as a customer can also act as a proxy if the project has been offered by an industrial partner, or some other department or organization on campus. As an architect initially specifying the overall structure of the solution, the instructor can help students choose the right software architecture. This is a very important choice that has to be made early because it impacts the overall flow of the project. Later architectural changes can be extremely costly and can significantly jeopardize meeting the deadlines. Most likely, students do not have experience in making such architectural decisions and, therefore, it is crucial for the instructor to provide some guidance in this important process. As a team manager concerned with risk management, the instructor needs to pay attention that the team efforts are not jeopardized due to a potential lack of students? soft skills and that these skills are built up as the project progresses. Although it is the students? responsibility to create all artifacts emerging from the project, the instructor can help the team adhere to the schedule by providing feedback based on the inspection of all produced artifacts. In this respect, the roles of the team manager and the customer may somewhat overlap because the same person will be providing feedback to the team from the technical point of view (artifact inspection), as well as from the customer point of view (verification of product implementation at each iteration). In addition to the traditional role of giving lectures, the instructor needs to be a mentor offering guidance to each team and individual students addressing their specific needs and answering questions unique to their projects and the responsibilities in the context of the project. Furthermore, the instructor is uniquely positioned to advise individual students on how to resolve potential conflicts within a team. Such an advice given at the right time could make a difference between completing the project on time and allowing interpersonal tensions completely ruin any chance of collaboration between the team members.