Visually Directed Debugging of Concurrent Programs

An extensive amount of work has been done on visualizing the execution of concurrent applications. This work has dealt with analysis of the use of the processors, analysis of the use of the communication network, and methods of representing data on the concurrent system. Representation of concurrent data has received the least attention. Our work extends the use of visual data representation by developing novel interaction techniques that provide for increased exploration possibilities. We describe the use of interactive steering techniques for changing data values, tracing selective data elements, controlling the flow of execution, and controlling the visualization display. These techniques help in exploring the data and computations, possibly identifying patterns, trends or errors. Our goal is to develop interactive steering techniques that could ultimately be applied to any visual representation of the data to provide greater understanding and control of the computational process. We also follow a philosophy of maintaining direct manipulation wherever possible.