Apportioning: a technique for efficient reachability analysis of concurrent object-oriented programs

The object-oriented paradigm has been found to be useful for the construction of large and complex concurrent systems. Reachability analysis is an important and well-known tool for static (pre-run-time) analysis of concurrent programs. However, direct application of traditional reachability analysis to concurrent object-oriented programs has many problems, such as incomplete analysis for reusable classes (not safe) and increased computational complexity (not efficient). We have proposed a novel technique called apportioning, for effective reachability analysis of concurrent object-oriented programs, that integrates the techniques of abstraction (considering a reduced representation of the system) and partitioning (dividing the system into smaller units). The given program is apportioned into a reduced version of each of its classes, as well as a reduced version of the program. The error to be checked is also decomposed into appropriate sub-properties for checking in the reachability graphs corresponding to the apportioned program. We have developed a number of apportioning-based algorithms, having different degrees of safety and effectiveness. In this paper, we present the details of one of these algorithms.