Staging Transformations for Multimodal Web Interaction Management

Multimodal interfaces are becoming increasingly ubiquitous with the advent of mobile devices, accessibility considerations, and novel software technologies that combine diverse interaction media. In addition to improving access and delivery capabilities, such interfaces enable flexible and personalized dialogs with websites, much like a conversation between humans. In this paper, we present a software framework for multimodal web interaction management that supports mixed-initiative dialogs between users and websites. A mixed-initiative dialog is one where the user and the website take turns changing the flow of interaction. The framework supports the functional specification and realization of such dialogs using staging transformations -- a theory for representing and reasoning about dialogs based on partial input. It supports multiple interaction interfaces, and offers sessioning, caching, and co-ordination functions through the use of an interaction manager. Two case studies are presented to illustrate the promise of this approach.Comment: Describes framework and software architecture for multimodal web interaction managemen

Fragmentación de programas con excepciones

[ES] La fragmentación de programas es una técnica de análisis de programas que puede ser aplicada prácticamente a todos los lenguajes de programación. Sin embargo, en presencia de excepciones, los fragmentadores de programas tienen un problema de precisión. Este proyecto aborda el problema de la fragmentación de programas en presencia de excepciones, analizando el problema desde una perspectiva general (para cualquier tipo de sistema de excepciones), pero concentrando nuestros esfuerzos en el paradigma de la orientación a objetos, más específicamente en el lenguaje Java. En esta tesis, estudiamos las soluciones existentes al problema planteado, y proponemos una generalización que incluye por lo menos las instrucciones 'try-catch' y 'throw'. Damos descripciones detalladas, generalizaciones y soluciones a dos problemas que aumentan innecesariamente el tamaño de los fragmentos de programa y un problema que reduce bastante la precisión. Las soluciones que proponemos producen fragmentos que garantizan la completitud y son tan correctos como es posible, dadas las restricciones marcadas por el sistema de manejo de excepciones. El análisis realizado y las soluciones propuestas son específicas para el lenguaje de programación Java y su sistema de manejo de excepciones, pero también son lo suficientemente generales como para poder ser empleadas en otros lenguajes de programación que posean un sistema de excepciones. También son específicas para la fragmentación estática hacia atrás, pero, del mismo modo, son compatibles con otras variantes en la fragmentación de programas.[EN] Program slicing is an analysis technique that can be applied to practically all programming languages. However, in the presence of exception handling, current program slicing software has a precision problem. This project tackles the problem of program slicing with exception handling, analysing the problem from a general perspective (for any kind of exception system), but focusing our efforts in the object-oriented paradigm, specifically the Java language. In this thesis, we study the currently available solutions to the problem, and we propose a generalization that includes at least the 'try-catch' and 'throw' statements. We provide detailed descriptions, generalizations and solutions for two problems that increase the size of slices and one problem that greatly reduces the precision of slices. The solutions we propose produce slices that guarantee completeness and are as correct as possible, given the restrictions set by the exception handling system. The analysis performed and solutions proposed are specific for the Java programming language, but are general enough that they can be ported effortlessly to other programming languages with similar exception handling capabilities. They are also specific for static backward slicing, but are likewise compatible with other variants of program slicing.Galindo Jiménez, CS. (2019). Fragmentación de programas con excepciones. http://hdl.handle.net/10251/136752TFG

The Interactive Curry Observation Debugger iCODE

AbstractDebugging by observing the evaluation of expressions and functions is a useful approach for finding bugs in lazy functional and functional logic programs. However, adding and removing observation annotations to a program is an effort making the use of this debugging technique in practice uncomfortable. Having tool support for managing observations is desirable. We developed a tool that provides this ability for programmers. Without annotating expressions in a program, the evaluation of functions, data structures and arbitrary subexpressions can be observed by selecting them from a tree-structure representing the whole program. Furthermore, the tool provides a step by step performing of observations where each observation is shown in a separated viewer. Beside searching bugs, the tool can be used to assist beginners in learning the non-deterministic behavior of lazy functional logic programs. To find a surrounding area that contains the failure, the tool can furthermore show the executed part of the program by marking the expressions that are activated during program execution

Sound and Precise Analysis of Multithreaded Programs through Schedule Specialization and Execution Filters

Multithreaded programs are known to be difficult to analyze. A key reason is that they typically have an enormous number of execution interleavings, or schedules. Static analysis with respect to all schedules requires over-approximation, resulting in poor precision; dynamic analysis rarely covers more than a tiny fraction of all schedules, so its result may not hold for schedules not covered. To address this challenge, we propose a novel approach called schedule specialization that restricts the schedules of a program to make it easier to analyze. Schedule specialization combines static and dynamic analysis. It first statically analyzes a multithreaded program with respect to a small set of schedules for precision, and then enforces these schedules at runtime for soundness of the static analysis results. To demonstrate that this approach works, we build three systems. The first system is a specialization framework that specializes a program into a simpler program based on a schedule for precision. It allows stock analyses to automatically gain precision with only little modification. The second system is Peregrine, a deterministic multithreading system that collects and enforces schedules on future inputs. Peregrine reuses a small set of schedules on many inputs, ensuring our static analysis results to be sound for a wide range of inputs. It also enforces these schedules efficiently, making schedule specialization suitable for production usage. Although schedule specialization can make static concurrency error detection more precise, some concurrency errors such as races may still slip detection and enter production systems. To mitigate this limitation, we build Loom, a live-workaround system that protects a live multithreaded program from races that slip detection. It allows developers to easily write execution filters to safely and efficiently work around deployed races in live multithreaded programs without restarting them

From Physics Model to Results: An Optimizing Framework for Cross-Architecture Code Generation

Starting from a high-level problem description in terms of partial differential equations using abstract tensor notation, the Chemora framework discretizes, optimizes, and generates complete high performance codes for a wide range of compute architectures. Chemora extends the capabilities of Cactus, facilitating the usage of large-scale CPU/GPU systems in an efficient manner for complex applications, without low-level code tuning. Chemora achieves parallelism through MPI and multi-threading, combining OpenMP and CUDA. Optimizations include high-level code transformations, efficient loop traversal strategies, dynamically selected data and instruction cache usage strategies, and JIT compilation of GPU code tailored to the problem characteristics. The discretization is based on higher-order finite differences on multi-block domains. Chemora's capabilities are demonstrated by simulations of black hole collisions. This problem provides an acid test of the framework, as the Einstein equations contain hundreds of variables and thousands of terms.Comment: 18 pages, 4 figures, accepted for publication in Scientific Programmin