Constructing Subtle Concurrency Bugs Using Synchronization-Centric Second-Order Mutation Operators

Mutation testing applies mutation operators to modify program source code or byte code in small ways, and then runs these modified programs (i.e., mutants) against a test suite in order to evaluate the quality of the test suite. In this paper, we first describe a general fault model for concurrent programs and some limitations of previously developed sets of first-order concurrency mutation operators. We then present our new mutation testing approach, which employs synchronization-centric second-order mutation operators that are able to generate subtle concurrency bugs not represented by the first-order mutation. These operators are used in addition to the synchronization-centric first-order mutation operators to form a small set of effective concurrency mutation operators for mutant generation. Our empirical study shows that our set of operators is effective in mutant generation with limited cost and demonstrates that this new approach is easy to implement.