Helping programmers improve the energy efficiency of source code

This paper briefly proposes a technique to detect energy inefficient fragments in the source code of a software system. Test cases are executed to obtain energy consumption measurements, and a statistical method, based on spectrum-based fault localization, is introduced to relate energy consumption to the system's source code. The result of our technique is an energy ranking of source code fragments pointing developers to possible energy leaks in their code.This work is financed by the ERDF European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundacao para a Ciencia e a Tecnologia within project POCI-01-0145-FEDER-016718 and UID/CEC/04516/2013; and by FLAD/NSF under the project Software Repositories for Green Computing, ref. 300/2015. The first author is also sponsored by FCT grant SFRH/BD/112733/2015

An economic energy approach for queries on data centers

Energy consumption is an issue that involves all of us, both as individuals and as members of a society, and covers all our areas of activity. It is something so broad that its impact has important reflections on our social, cultural and financial structures. The domain of software, and in particular database systems, is not an exception. Although it seems to be a little bit strange to study the energy consumption of just one query, when we consider the execution of a a few thousand queries per second, quickly we see the importance of the querying consumption in the monthly account of any company that has a conventional data center. To demonstrate the energy consumption of queries in data centers, we idealized a small dashboard for monitoring and analyzing the sales of a company, and implemented all the queries needed for populating it and ensuring its operation. The queries were organized into two groups, oriented especially to two distinct database management systems: one relational (MySQL) and one non relational (Neo4J). The goal is to evaluate the energy consumption of different types of queries, and at the same time compare it in terms of relational and non-relational database approaches. This paper relates the process we implemented to set up the energy consumption application scenario, measure the energy consumption of each query, and present our first preliminary results

Towards a green ranking for programming languages

While in the past the primary goal to optimize software was the run time optimization, nowadays there is a growing awareness of the need to reduce energy consumption. Additionally, a growing number of developers wish to become more energy-aware when programming and feel a lack of tools and the knowledge to do so.In this paper we define a ranking of energy efficiency in programming languages. We consider a set of computing problems implemented in ten well-known programming languages, and monitored the energy consumed when executing each language. Our preliminary results show that although the fastest languages tend to be the lowest consuming ones, there are other interesting cases where slower languages are more energy efficient than faster ones.This work is financed by the ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundacao para a Ciencia e a Tecnologia within project POCI-01-0145-FEDER-016718. The second author is also sponsored by FCT grant SFRH/BD/112733/2015

Ranking programming languages by energy efficiency

This paper compares a large set of programming languages regarding their efficiency, including from an energetic point-of-view. Indeed, we seek to establish and analyze different rankings for programming languages based on their energy efficiency. The goal of being able to rank languages with energy in mind is a recent one, and certainly deserves further studies. We have taken 19 solutions to well defined programming problems, expressed in (up to) 27 programming languages, from well know repositories such as the Computer Language Benchmark Game and Rosetta Code. We have also built a framework to automatically, and systematically, run, measure and compare the efficiency of such solutions. Ultimately, it is based on such comparison that we propose a serious of efficiency rankings, based on multiple criteria. Our results show interesting findings, such as, slower/faster languages consuming less/more energy, and how memory usage influences energy consumption. We also show how to use our results to provide software engineers support to decide which language to use when energy efficiency is a concern(University of Porto) for the help that he provided. This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme within project POCI-01-0145-FEDER-006961, and by National Funds through the Portuguese funding agency, FCT - Funda¸c˜ao para a Ciˆencia e a Tecnologia within project POCI-01-0145-FEDER-016718 and UID/EEA/50014/2013. The first and second authors are also sponsored by FCT grants SFRH/BD/112733/2015 and SFRH/BD/132485/201

EDSL en Haskell para la programaci ́on segura respecto a la propiedad Delimited Release

La confidencialidad de la información manipulada por sistemas informáticos ha tomado mayor importancia con el uso creciente de aplicaciones a través de internet. Los mecanismos de seguridad tradicionales como control de acceso o criptografía no proveen protección punta a punta de los datos: funcionan eficientemente en limitar su acceso, pero no pueden hacer nada para evitar su propagación. Para complementar estos mecanismos de seguridad, surgen las técnicas de control de flujo de información (IFC, Information-Flow Control), las cuales permiten establecer garantías sobre la confidencialidad e integridad de los datos. analizando cómo fluye la información dentro del programa. En este contexto surgen políticas de confidencialidad que garantizan que la información confidencial no puede ser inferida a partir de los datos públicos. No-interferencia es un ejemplo de una política de seguridad. Lo interesante de esta propiedad es que puede ser chequeada de manera estática mediante un sistema de tipos, por lo tanto, cuando un programa tipa en ese sistema de tipos, significa que satisface la propiedad de seguridad. Para que los lenguajes de seguridad tengan utilidad práctica necesitamos mecanismos de desclasificación, en los cuales el flujo de información sea controlado y al mismo tiempo se permita liberar información confidencial a canales públicos, pero solo de manera permitida y controlada, la cual la propiedad de no-interferencia resulta ser demasiado restrictiva. Delimited Release es una propiedad de seguridad que garantiza que la desclasificación no puede ser usada para filtrar información de manera no deseada. El objetivo de esta tesina es desarrollar un lenguaje de dominio específico embebido en Haskell para escribir programas seguros respecto a la propiedad Delimited Release