Immediacy through Interactivity: Online Analysis of Run-time Behavior

Visualizations of actual run-time data support the comprehension of programs, like examples support the explanation of abstract concepts and principles. Unfortunately, the required run-time analysis is often associated with an inconvenient overhead that renders current tools impractical for frequent use. We propose an interactive approach to collect and present run-time data. An initial shallow analysis provides for immediate access to visualizations of run-time information. As users explore this information, it is incrementally refined on-demand. We present an implementation that realizes our proposed approach and enables developers to instantly explore run-time behavior of selected code entities. We evaluate our interactive approach by measuring time and memory overhead in the context of ten different-sized projects. Our empirical results show that run-time data for an initial overview can be collected in less than 300 milliseconds for 95% of cases.