Thu 25 Mar 2021 13:00 - 13:30 at Virtual Space B - Session 8 Chair(s): Simon Fowler
Fri 26 Mar 2021 14:00 - 14:30 at Virtual Space B - Session 15 Chair(s): Stefan Marr

Context. Refining or altering existing behavior is the daily work of every developer, but that cannot be always anticipated, and software sometimes cannot be stopped. In such cases, unanticipated adaptation of running systems is of interest for many scenarios, ranging from functional upgrades to on-the-fly debugging or monitoring of critical applications.

Inquiry. A way of altering software at run time is using behavioral reflection, which is particularly well- suited for unanticipated adaptation of real-world systems. Partial behavioral reflection is not a new idea, and for years many efforts have been made to propose a practical way of expressing it. All these efforts resulted in practical solutions, but which introduced a semantic gap between the code that requires adaptation and the expression of the partial behavior. For example, in Aspect-Oriented Programming, a pointcut description is expressed in another language, which introduces a new distance between the behavior expression (the Advice) and the source code in itself.

Approach. Ten years ago, the idea of closing the gap between the code and the expression of the partial behavior led to the implementation of the Reflectivity framework. Using Reflectivity, developers annotate Ab- stract Syntax Tree (AST) nodes with meta-behavior which is taken into account by the compiler to produce behavioral variations. In this paper, we present Reflectivity, its API, its implementation and its usage in Pharo. We reflect on ten years of use of Reflectivity, and show how it has been used as a basic building block of many innovative ideas.

Knowledge. Reflectivity brings a practical way of working at the AST level, which is a high-level repre- sentation of the source code manipulated by software developers. It enables a powerful way of dynamically add and modify behavior. Reflectivity is also a flexible mean to bridge the gap between the expression of the meta-behavior and the source code. This ability to apply unanticipated adaptation and to provide behavioral reflection led to many experiments and projects during this last decade by external users. Existing work use Reflectivity to implement reflective libraries or languages extensions, featherweight code instrumentation, dynamic software update, debugging tools and visualization and software analysis tools.

Grounding. Reflectivity is actively used in research projects. During the past ten years, it served as a support, either for implementation or as a fundamental base, for many research work including PhD theses, conference, journal and workshop papers. Reflectivity is now an important library of the Pharo language, and is integrated at the heart of the platform.

Importance. Reflectivity exposes powerful abstractions to deal with partial behavioral adaptation, while providing a mature framework for unanticipated, non-intrusive and partial behavioral reflection based on AST annotation. Furthermore, even if Reflectivity found its home inside Pharo, it is not a pure Smalltalk-oriented solution. As validation over the practical use of Reflectivity in dynamic object-oriented languages, the API has been ported to Python. Finally, the AST annotation feature of Reflectivity opens new experimentation opportunities about the control that developers could gain on the behavior of their own software.

Conference Day
Thu 25 Mar

Displayed time zone: Belfast change

13:00 - 14:30
Session 8Research Papers at Virtual Space B
Chair(s): Simon FowlerUniversity of Glasgow
13:00
30m
Live Q&A
Sub-method, partial behavioral reflection with Reflectivity: Looking back on 10 years of use
Research Papers
Steven Costiou INRIA Lille, Vincent AranegaUniversité Lille, CNRS, Centrale Lille, Inria, UMR 9189 - CRIStAL, Marcus Denker INRIA Lille
DOI Media Attached
13:30
30m
Live Q&A
Reference Capabilities for Safe Parallel Array Programming
Research Papers
Beatrice ÅkerblomStockholm University, Elias CastegrenKTH, Tobias WrigstadUppsala University, Sweden
DOI Media Attached
14:00
30m
Live Q&A
ReactiFi: Reactive Programming of Wi-Fi Firmware on Mobile Devices
Research Papers
Artur SterzPhilipps-Universität Marburg, Matthias Eichholz, Ragnar MogkTechnische Universität Darmstadt, Lars BaumgärtnerTechnische Universität Darmstadt, Pablo Graubner, Matthias Hollick, Mira MeziniTU Darmstadt, Germany, Bernd FreislebenPhilipps-Universität Marburg
DOI Media Attached

Conference Day
Fri 26 Mar

Displayed time zone: Belfast change

13:30 - 14:30
Session 15Research Papers at Virtual Space B
Chair(s): Stefan MarrUniversity of Kent
13:30
30m
Live Q&A
Transparent Compiler and Runtime Specializations for Accelerating Managed Languages on FPGAs
Research Papers
Michail PapadimitriouUniversity of Manchester, UK, Juan FumeroUniversity of Manchester, UK, Athanasios StratikopoulosThe University of Manchester, Foivos S. ZakkakRed Hat, Inc., Christos KotselidisKTM Innovation / The University of Manchester
DOI Media Attached
14:00
30m
Live Q&A
Sub-method, partial behavioral reflection with Reflectivity: Looking back on 10 years of use
Research Papers
Steven Costiou INRIA Lille, Vincent AranegaUniversité Lille, CNRS, Centrale Lille, Inria, UMR 9189 - CRIStAL, Marcus Denker INRIA Lille
DOI Media Attached