TY - JOUR A1 - Rein, Patrick A1 - Ramson, Stefan A1 - Lincke, Jens A1 - Felgentreff, Tim A1 - Hirschfeld, Robert T1 - Group-Based Behavior Adaptation Mechanisms in Object-Oriented Systems JF - IEEE software N2 - Dynamic and distributed systems require behavior adaptations for groups of objects. Group-based behavior adaptation mechanisms scope adaptations to objects matching conditions beyond class membership. The specification of groups can be explicit or implicit. KW - group-based behavior adaptation KW - lively groups KW - ContextErlang KW - entity-component-system KW - predicated generic functions KW - active layers KW - reactive object queries KW - context groups KW - implied methods KW - object-oriented languages KW - software engineering KW - software development KW - contextual-variability modeling Y1 - 2017 U6 - https://doi.org/10.1109/MS.2017.4121224 SN - 0740-7459 SN - 1937-4194 VL - 34 IS - 6 SP - 78 EP - 82 PB - Inst. of Electr. and Electronics Engineers CY - Los Alamitos ER - TY - JOUR A1 - Perscheid, Michael A1 - Siegmund, Benjamin A1 - Taeumel, Marcel A1 - Hirschfeld, Robert T1 - Studying the advancement in debugging practice of professional software developers JF - Software Quality Journal N2 - In 1997, Henry Lieberman stated that debugging is the dirty little secret of computer science. Since then, several promising debugging technologies have been developed such as back-in-time debuggers and automatic fault localization methods. However, the last study about the state-of-the-art in debugging is still more than 15 years old and so it is not clear whether these new approaches have been applied in practice or not. For that reason, we investigate the current state of debugging in a comprehensive study. First, we review the available literature and learn about current approaches and study results. Second, we observe several professional developers while debugging and interview them about their experiences. Third, we create a questionnaire that serves as the basis for a larger online debugging survey. Based on these results, we present new insights into debugging practice that help to suggest new directions for future research. KW - Debugging KW - Literature review KW - Field study KW - Online survey Y1 - 2016 U6 - https://doi.org/10.1007/s11219-015-9294-2 SN - 0963-9314 SN - 1573-1367 VL - 25 SP - 83 EP - 110 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Felgentreff, Tim A1 - Perscheid, Michael A1 - Hirschfeld, Robert T1 - Implementing record and refinement for debugging timing-dependent communication JF - Science of computer programming N2 - Distributed applications are hard to debug because timing-dependent network communication is a source of non-deterministic behavior. Current approaches to debug non deterministic failures include post-mortem debugging as well as record and replay. However, the first impairs system performance to gather data, whereas the latter requires developers to understand the timing-dependent communication at a lower level of abstraction than they develop at. Furthermore, both approaches require intrusive core library modifications to gather data from live systems. In this paper, we present the Peek-At-Talk debugger for investigating non-deterministic failures with low overhead in a systematic, top-down method, with a particular focus on tool-building issues in the following areas: First, we show how our debugging framework Path Tools guides developers from failures to their root causes and gathers run-time data with low overhead. Second, we present Peek-At-Talk, an extension to our Path Tools framework to record non-deterministic communication and refine behavioral data that connects source code with network events. Finally, we scope changes to the core library to record network communication without impacting other network applications. KW - Distributed debugging KW - Record and replay KW - Dynamic analysis KW - Record and refinement Y1 - 2016 U6 - https://doi.org/10.1016/j.scico.2015.11.006 SN - 0167-6423 SN - 1872-7964 VL - 134 SP - 4 EP - 18 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rein, Patrick A1 - Taeumel, Marcel A1 - Hirschfeld, Robert T1 - Making the domain tangible BT - implicit object lookup for source code readability JF - Design Thinking Research N2 - Programmers collaborate continuously with domain experts to explore the problem space and to shape a solution that fits the users’ needs. In doing so, all parties develop a shared vocabulary, which is above all a list of named concepts and their relationships to each other. Nowadays, many programmers favor object-oriented programming because it allows them to directly represent real-world concepts and interactions from the vocabulary as code. However, when existing domain data is not yet represented as objects, it becomes a challenge to initially bring existing domain data into object-oriented systems and to keep the source code readable. While source code might be comprehensible to programmers, domain experts can struggle, given their non-programming background. We present a new approach to provide a mapping of existing data sources into the object-oriented programming environment. We support keeping the code of the domain model compact and readable while adding implicit means to access external information as internal domain objects. This should encourage programmers to explore different ways to build the software system quickly. Eventually, our approach fosters communication with the domain experts, especially at the beginning of a project. When the details in the problem space are not yet clear, the source code provides a valuable, tangible communication artifact. KW - Source Code Readability KW - Domain Objects KW - StackOverflow KW - Squeak KW - Custom Writable Class Y1 - 2017 SN - 978-3-319-60967-6 SN - 978-3-319-60966-9 U6 - https://doi.org/10.1007/978-3-319-60967-6_9 SP - 171 EP - 194 PB - Springer CY - New York ER - TY - JOUR A1 - Pape, Tobias A1 - Bolz, Carl Friedrich A1 - Hirschfeld, Robert T1 - Adaptive just-in-time value class optimization for lowering memory consumption and improving execution time performance JF - Science of computer programming N2 - The performance of value classes is highly dependent on how they are represented in the virtual machine. Value class instances are immutable, have no identity, and can only refer to other value objects or primitive values and since they should be very lightweight and fast, it is important to optimize them carefully. In this paper we present a technique to detect and compress common patterns of value class usage to improve memory usage and performance. The technique identifies patterns of frequent value object references and introduces abbreviated forms for them. This allows to store multiple inter-referenced value objects in an inlined memory representation, reducing the overhead stemming from meta data and object references. Applied to a small prototype and an implementation of the Racket language, we found improvements in memory usage and execution time for several micro-benchmarks. (C) 2016 Elsevier B.V. All rights reserved. KW - Meta-tracing KW - JIT KW - Data structure optimization KW - Value classes Y1 - 2017 U6 - https://doi.org/10.1016/j.scico.2016.08.003 SN - 0167-6423 SN - 1872-7964 VL - 140 SP - 17 EP - 29 PB - Elsevier CY - Amsterdam ER - TY - BOOK A1 - Niephaus, Fabio A1 - Felgentreff, Tim A1 - Hirschfeld, Robert T1 - Squimera BT - a live, Smalltalk-based IDE for dynamic programming languages N2 - Programmierwerkzeuge, die verschiedene Programmiersprachen unterstützen und sich konsistent bedienen lassen, sind hilfreich für Softwareentwickler, weil diese sich nicht erst mit neuen Werkzeugen vertraut machen müssen, wenn sie in einer neuen Sprache entwickeln wollen. Außerdem ist es nützlich, verschiedene Programmiersprachen in einer Anwendung kombinieren zu können, da Entwickler dann Softwareframeworks und -bibliotheken nicht in der jeweiligen Sprache nachbauen müssen und stattdessen bestehende Software wiederverwenden können. Dennoch haben Entwickler eine sehr große Auswahl, wenn sie nach Werkzeugen suchen, die teilweise zudem speziell nur für eine Sprache ausgelegt sind. Einige integrierte Entwicklungsumgebungen unterstützen verschiedene Programmiersprachen, können aber häufig keine konsistente Bedienung ihrer Werkzeuge gewährleisten, da die jeweiligen Ausführungsumgebungen der Sprachen zu verschieden sind. Darüber hinaus gibt es bereits Mechansimen, die es erlauben, Programme aus anderen Sprachen in einem Programm wiederzuverwenden. Dazu werden häufig das Betriebssystem oder eine Netzwerkverbindung verwendet. Programmierwerkzeuge unterstützen jedoch häufig eine solche Indirektion nicht und sind deshalb nur eingeschränkt nutzbar bei beispielsweise Debugging Szenarien. In dieser Arbeit stellen wir einen neuartigen Ansatz vor, der das Programmiererlebnis in Bezug auf das Arbeiten mit mehreren dynamischen Programmiersprachen verbessern soll. Dazu verwenden wir die Werkzeuge einer Smalltalk Programmierumgebung wieder und entwickeln eine virtuelle Ausführungsumgebung, die verschiedene Sprachen gleichermaßen unterstützt. Der auf unserem Ansatz basierende Prototyp Squimera demonstriert, dass es möglich ist, Programmierwerkzeuge in der Art wiederzuverwenden, sodass sie sich für verschiedene Programmiersprachen gleich verhalten und somit die Arbeit für Entwickler vereinfachen. Außerdem ermöglicht Squimera einfaches Wiederverwenden und darüber hinaus das Verschmischen von in unterschiedlichen Sprachen geschriebenen Softwarebibliotheken und -frameworks und erlaubt dabei zusätzlich Debugging über mehrere Sprachen hinweg. N2 - Software development tools that work and behave consistently across different programming languages are helpful for developers, because they do not have to familiarize themselves with new tooling whenever they decide to use a new language. Also, being able to combine multiple programming languages in a program increases reusability, as developers do not have to recreate software frameworks and libraries in the language they develop in and can reuse existing software instead. However, developers often have a broad choice with regard to tools, some of which are designed for only one specific programming language. Various Integrated Development Environments have support for multiple languages, but are usually unable to provide a consistent programming experience due to different features of language runtimes. Furthermore, common mechanisms that allow reuse of software written in other languages usually use the operating system or a network connection as the abstract layer. Tools, however, often cannot support such indirections well and are therefore less useful in debugging scenarios for example. In this report, we present a novel approach that aims to improve the programming experience with regard to working with multiple high-level programming languages. As part of this approach, we reuse the tools of a Smalltalk programming environment for other languages and build a multi-language virtual execution environment which is able to provide the same runtime capabilities for all languages. The prototype system Squimera is an implementation of our approach and demonstrates that it is possible to reuse development tools, so that they behave in the same way across all supported programming languages. In addition, it provides convenient means to reuse and even mix software libraries and frameworks written in different languages without breaking the debugging experience. T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 120 KW - Programmiererlebnis KW - integrierte Entwicklungsumgebungen KW - mehrsprachige Ausführungsumgebungen KW - Interpreter KW - Debugging KW - Smalltalk KW - Python KW - Ruby KW - programming experience KW - integrated development environments KW - polyglot execution environments KW - interpreters KW - debugging KW - small talk KW - Python KW - Ruby Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403387 SN - 978-3-86956-422-7 IS - 120 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - BOOK A1 - Weyand, Christopher A1 - Chromik, Jonas A1 - Wolf, Lennard A1 - Kötte, Steffen A1 - Haase, Konstantin A1 - Felgentreff, Tim A1 - Lincke, Jens A1 - Hirschfeld, Robert T1 - Improving hosted continuous integration services T1 - Verbesserung gehosteter Dienste für kontinuierliche Integration N2 - Developing large software projects is a complicated task and can be demanding for developers. Continuous integration is common practice for reducing complexity. By integrating and testing changes often, changesets are kept small and therefore easily comprehensible. Travis CI is a service that offers continuous integration and continuous deployment in the cloud. Software projects are build, tested, and deployed using the Travis CI infrastructure without interrupting the development process. This report describes how Travis CI works, presents how time-driven, periodic building is implemented as well as how CI data visualization can be done, and proposes a way of dealing with dependency problems. N2 - Große Softwareprojekte zu entwickeln, ist eine komplizierte Aufgabe und fordernd für Entwickler. Kontinuierliche Integration ist eine geläufige Praxis zur Komplexitätsreduktion. Durch häufiges Integrieren und Testen werden Änderungen klein gehalten und sind daher übersichtlich. Travis CI ist ein Dienst, der kontinuierliche Integration und kontinuierliche Bereitstellung in der Cloud anbietet. Softwareprojekte werden auf der Travis CI Infrastruktur gebaut, getestet und bereitgestellt, ohne dass der Entwicklungsprozess unterbrochen wird. Dieser Bericht beschreibt, die Travis CI funktioniert, zeigt wie zeitgesteuertes, periodisches Bauen implentiert wurde, wie CI-Daten visualisiert werden können und schlägt ein Verfahren vor mit dem Abhängigkeitsprobleme gelöst werden können. T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 108 KW - Travis CI KW - continuous integration KW - continuous testing KW - software tests KW - software architecture KW - periodic tasks KW - dependencies KW - visualization KW - Travis CI KW - kontinuierliche Integration KW - kontinuierliches Testen KW - Softwaretests KW - Softwarearchitektur KW - periodische Aufgaben KW - Abhängigkeiten KW - Visualisierung Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94251 SN - 978-3-86956-377-0 SN - 1613-5652 SN - 2191-1665 IS - 108 PB - Universitätsverlag Potsdam CY - Potsdam ER -