New Approaches to Contention-Sensitive Nested Locking in Real-Time Systems

Nested lock requests in multiprocessor real-time systems can be handled by only a handful of synchronization protocols. These protocols trade off overhead and blocking under varying analysis assumptions. In some systems, a finegrained contention-sensitive protocol has significantly lower worst-case blocking compared to its non-contention-sensitive counterparts, which yields improved schedulability provided overheads are low enough. In this work, we summarize three key schemes for handling nested requests and briefly discuss existing protocols. We then propose three approaches to reduce the often interdependent overhead and blocking for a new contention-sensitive protocol.