Static Deadlock Detection for Java Libraries

Library writers wish to provide a guarantee not only that each procedure in the library performs correctly in isolation, but also that the procedures perform correctly when run in conjunction. To this end, we propose a method for static detection of deadlock in Java libraries. Our goal is to determine whether client code exists that may deadlock a library, and, if so, to enable the library writer to discover the calling patterns that can lead to deadlock. Our flow-sensitive, context-sensitive analysis determines possible deadlock configurations using a lock-order graph. This graph represents the order in which locks are acquired by the library. Cycles in the graph indicate deadlock possibilities, and our tool reports all such possibilities. We implemented our analysis and evaluated it on 18 libraries comprising 1245 kLOC. We verified 13 libraries to be free from deadlock, and found 14 distinct deadlocks in 3 libraries.