A Contention-Sensitive Fine-Grained Locking Protocol for Multiprocessor Real-Time Systems∗

Prior work on multiprocessor real-time locking protocols has shown how to support fine-grained lock nesting with asymptotically optimal worst-case priority-inversion blocking (pi-blocking) bounds. However, contention for each resource has heretofore been considered an unconstrained variable. This paper presents the first fine-grained multiprocessor real-time locking protocol with contention-sensitive worst-case pi-blocking bounds. Contention-sensitive pi-blocking is made possible by incorporating knowledge of maximum critical-section lengths—which must be known a priori for analysis anyway—into the lock logic. 1