Verifying Nested Lock Priority Inheritance in RTEMS with Java Pathfinder.

Scheduling and synchronization algorithms for uniprocessor real-time systems benefit from the rich theory of schedulability analysis, and yet translating these algorithms to practical implementations can be challenging. This paper presents a Java model of the priority inheritance protocol for mutual exclusion, as implemented in the RTEMS open-source real-time operating system. We verified this model using Java Pathfinder to detect potential data races, deadlocks, and priority inversions. JPF detected a known bug in the RTEMS implementation, which we modified along with the Java model. Verification of the modified model showed the absence of data races, deadlocks, and established nine protocol-specific correctness properties.