Issues in visualization for the comprehension of parallel programs

Parallel and distributed computers are becoming more widely used. Thus, the comprehension of parallel programs is increasingly important. Understanding parallel programs is more challenging than understanding serial programs because of the issues of concurrency, scale, communications, shared resources, and shared state. In this article, we argue that the use of visualizations and animations of programs can be an invaluable asset to program comprehension. We present example problems and visualizations, showing how graphical displays can assist program understanding. We also describe the Animation Choreographer, a tool that helps programmers better comprehend the temporal characteristics of their programs