Detecting interleaving

The various goals and requirements of a system are realized in software as fragments of code that are typically "interleaved" in that they may be woven together in the same contiguous textual area of code. The fragments of code are often delocalized and overlap rather than being composed in a simple linear sequence. Interleaving severely complicates software comprehension and maintenance. To address this problem, we are developing analysis tools, based on the Software Refinery. This paper describes our experiences in detecting interleaving in a corpus of mathematical software written in Fortran from the Jet Propulsion Laboratory. In particular, it discusses how feasible it is to detect interleaving of various types and the ability of existing tools to assist these types of detection.