Bringing Back-in-Time Debugging Down to the Database

With back-in-time debuggers, developers can explore what happened before observable failures by following infection chains back to their root causes. While there are several such debuggers for object-oriented programming languages, we do not know of any back-in-time capabilities at the database-level. Thus, if failures are caused by SQL scripts or stored procedures, developers have difficulties in understanding their unexpected behavior. In this paper, we present an approach for bringing back-in-time debugging down to the SAP HANA in-memory database. Our TARDISP debugger allows developers to step queries backwards and inspecting the database at previous and arbitrary points in time. With the help of a SQL extension, we can express queries covering a period of execution time within a debugging session and handle large amounts of data with low overhead on performance and memory. The entire approach has been evaluated within a development project at SAP and shows promising results with respect to the gathered developer feedback.Comment: 24th IEEE International Conference on Software Analysis, Evolution, and Reengineerin

Developing a Generic Debugger for Advanced-Dispatching Languages

Programming-language research has introduced a considerable number of advanced-dispatching mechanisms in order to improve modularity. Advanced-dispatching mechanisms allow changing the behavior of a function without modifying their call sites and thus make the local behavior of code less comprehensible. Debuggers are tools, thus needed, which can help a developer to comprehend program behavior but current debuggers do not provide inspection of advanced-\ud dispatching-related language constructs. In this paper, we present a debugger which extends a traditional Java debugger with the ability of debugging an advanced-dispatching language constructs and a user interface for inspecting this

Debugging Woven Code

The ability to debug woven programs is critical to the adoption of Aspect Oriented Programming (AOP). Nevertheless, many AOP systems lack adequate support for debugging, making it difficult to diagnose faults and understand the program's structure and control flow. We discuss why debugging aspect behavior is hard and how harvesting results from related research on debugging optimized code can make the problem more tractable. We also specify general debugging criteria that we feel all AOP systems should support. We present a novel solution to the problem of debugging aspect-enabled programs. Our Wicca system is the first dynamic AOP system to support full source-level debugging of woven code. It introduces a new weaving strategy that combines source weaving with online byte-code patching. Changes to the aspect rules, or base or aspect source code are rewoven and recompiled on-the-fly. We present the results of an experiment that show how these features provide the programmer with a powerful interactive debugging experience with relatively little overhead

Toward Secure Services from Untrusted Developers

We present a secure service prototype built from untrusted,contributed code.The service manages private data for a variety of different users, anduser programs frequently require access to other users' private data.However, aside from covert timing channels, no part of the service cancorrupt private data or leak it between users or outside the systemwithout permission from the data's owners.Instead, owners may choose to reveal their data in a controlled manner.This application model is demonstrated by Muenster, a job searchwebsite that protects both the integrity and secrecy of each user's data.In spite of running untrusted code, Muenster and other services canprevent overt leaks because the untrusted modules are constrained bythe operating system to follow pre-specified security policies, whichare nevertheless flexible enough for programmers to do useful work.We build Muenster atop Asbestos, a recently described operating systembased on a form of decentralized information flowcontrol

CodeBase Relationship Visualizer: Visualizing Relationships Between Source Code Files

Understanding relationships between files and their directory structure is a fundamental part of the software development process. However, it can be hard to grasp these relationships without a convenient way to visualize how files are connected and how they fit into the directory structure of the codebase. In this paper we describe CodeBase Relationship Visualizer (CBRV), a Visual Studio Code extension that interactively visualizes the relationships between files. CBRV displays the relationships between files as arrows superimposed over a diagram of the codebase\u27s directory structure. CBRV comes bundled with visualizations of the stack trace path, a dependency graph for Python codebases, and a hyperlink graph for HTML and Markdown. CBRV also exposes an API that can be used to create visualizations for multiple different relationships. CBRV is a convenient and easy-to-use tool that offers a big picture perspective on the relationships within a codebase

MPSoC Zoom Debugging: A Deterministic Record-Partial Replay Approach

Accepté à EUC'2014International audienceThis work presents a debugging methodology for MPSoC based on deterministic record-replay. We propose a general model of MPSoC and define a debugging cycle targeting errors by applying temporal and spatial selection criteria. 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 for a visual representation of the considered part of the trace. The approach is validated on two execution platforms and two multimedia applications