Dynamic Analysis of Java Program Concepts

5 Concept assignment identifies units of source code that are functionally related, 6 even if this is not apparent from a syntactic point of view. Until now, the results 7 of concept assignment have only been used for static analysis, mostly of program 8 source code. This paper investigates the possibility of using concept information 9 within a framework for dynamic analysis of programs. The paper presents two case 10 studies involving a small Java program used in a previous research exercise, and a 11 large Java virtual machine (the popular Jikes RVM system). These studies investi12 gate two applications of dynamic concept information: visualization and profiling. 13 The paper demonstrates two different styles of concept visualization, which show 14 the proportion of overall time spent in each concept and the sequence of concept 15 execution, respectively. The profiling study concerns the interaction between run16 time compilation and garbage collection in Jikes RVM. For some benchmark cases, 17 we are able to obtain a significant reduction in garbage collection time. We discuss 18 how this phenomenon might be harnessed to optimize the scheduling of garbage 19 collection in Jikes RVM. 20