Deterministic Partial Replay for MPSoC Debugging

This work reports on a debugging methodology for MPSoC based on deterministic record-replay. It defines a general model of MPSoC, identifies the major sources for non determinism and selects a set of adapted algorithms for the record and replay of non deterministic errors. The contribution of this work the definition of a debugging cycle targeting errors by applying temporal and spatial selection criteria. is the proposal of and . The idea behind spatial and temporal selection is to consider not the entire execution of the whole application but replay a part of the application during a specific execution interval. The proposed mechanisms are connected to GDB and allow a visual representation of the considered part of the trace. The approach has been validated on two execution platforms and two multimedia applications.Ce rapport présente une méthodologie de débogage pour les systèmes MPSoC basée sur l'enregistrement et la ré-exécution déterministe de traces d'exécution. Ce travail propose un modèle général des systèmes MPSoC, identifie les principales sources de non-déterminisme et propose l'application d'algorithmes adaptés pour l'enregistrement et la ré-exécution d'erreurs non-déterministes. L'originalité du travail réside dans la définition d'un cycle de débogage permettant de cibler la recherche des erreurs en appliquant des critères de sélection spatiale et temporelle. La sélection spatiale consiste à ne considérer qu'une partie de l'application en exécution. La sélection temporelle permet de ne considérer qu'un intervalle spécifique d'exécution. Les mécanismes sont connectées à l'outil de débogage standard GDB tout en fournissant une représentation visuelle de la portion de trace considérée. L'approche est validée sur deux types de plateformes et avec deux applications multimédia

Is there Joy Beyond the Joystick?: Immersive Potential of Brain-Computer Interfaces

Immersion, the state of being fully engaged in one\u27s current operation, is a descriptor commonly used to appraise user experience in computer games and software applications. As the use of brain-computer interfaces (BCIs) begins to expand into the consumer sphere, questions arise concerning the ability of BCIs to modulate user immersion. This study employed a computer game to examine the effect of a consumer-grade BCI (the Emotiv EPOC) on immersion. In doing so, this study also explored the relationship between BCI usability and immersion levels. An experiment with twenty-seven participants showed that users were significantly more immersed when controlling the testing game with a BCI in comparison to traditional control methods. The results suggest that increased immersion levels may be caused by the challenging nature of BCI control rather than the BCI\u27s ability to directly translate user intent

Digital games as simulations

Conference paper and presentation slide

Soft Contract Verification

Behavioral software contracts are a widely used mechanism for governing the flow of values between components. However, run-time monitoring and enforcement of contracts imposes significant overhead and delays discovery of faulty components to run-time. To overcome these issues, we present soft contract verification, which aims to statically prove either complete or partial contract correctness of components, written in an untyped, higher-order language with first-class contracts. Our approach uses higher-order symbolic execution, leveraging contracts as a source of symbolic values including unknown behavioral values, and employs an updatable heap of contract invariants to reason about flow-sensitive facts. We prove the symbolic execution soundly approximates the dynamic semantics and that verified programs can't be blamed. The approach is able to analyze first-class contracts, recursive data structures, unknown functions, and control-flow-sensitive refinements of values, which are all idiomatic in dynamic languages. It makes effective use of an off-the-shelf solver to decide problems without heavy encodings. The approach is competitive with a wide range of existing tools---including type systems, flow analyzers, and model checkers---on their own benchmarks.Comment: ICFP '14, September 1-6, 2014, Gothenburg, Swede