An Empirical Study of Java Dynamic Call Graph Extractors

A dynamic call graph is the invocation relation that represents a specific set of runtime executions of a program. Dynamic call graph extraction is a typical application of dynamic analysis to aid compiler optimization, performance analysis, program understanding, etc. In this paper, we empirically compare the results of nine Java dynamic call graph extractors quantitatively and qualitatively. We investigate those differences among the dynamic call graph extracted by different tools mainly caused by different underlying Java program instrumentation techniques and other design decisions. A comparison between static call graph and dynamic call graph shows software engineering tools for program understanding place a different requirement on dynamic call graph from compilers or profilers whose main purpose is optimization or performance tuning. Dynamic call graphs require some complementary static information and an effective representation to aid program understanding. Choosing an appropriate instrumentation technique, integrating static and dynamic information, and providing flexible user manipulation for dynamic call graphs can better facilitate program understanding task. In this paper, we discuss the study and sketch the design considerations for an effective dynamic call graph tool to support program understanding.