Sofya: A Flexible Framework for Development of Dynamic Program Analyses for Java Software

Dynamic analysis techniques are well established in the software engineering community as methods for validating, understanding, maintaining, and improving programs. Generally, this class of techniques requires developers to instrument programs to generate events that capture, or observe, relevant features of program execution. Streams of these events are then processed to achieve the goals of the dynamic analysis. The lack of high-level tools for defining program observations, automating their mapping to efficient low-level implementations, and supporting the flexible combination of different event-stream-based processing components hampers the development and evaluation of new dynamic analysis techniques. For example, mapping non-trivial program observations to existing low-level instrumentation facilities is a time-consuming and error-prone process that can easily result in poorly performing analyses. In this paper, we present Sofya - a framework that we have developed for building dynamic analysis tools. We describe the architecture of Sofya, and explain how it meets the challenges faced by developers of a wide-range of dynamic analyses. We survey existing dynamic analysis tools to show how they relate to the capabilities of the Sofya framework, and we show how Sofya improves on their shortcomings. Finally, to illustrate the flexibility and effectiveness of the framework, we describe our experiences developing several state-of-the-art dynamic analyses using Sofya