A Real-Time Locking Protocol
April 1989 • Technical Report
Lui R. Sha, Ragunathan Rajkumar, Sang Son, Chang Chun-Hyon
This 1989 report examines a priority-driven, two-phase lock protocol called the read- or write-priority ceiling protocol.
Software Engineering Institute
CMU/SEI Report Number
When a database system is used in a real-time application, the concurrency control protocol must satisfy not only the consistency of shared data but also the timing constraints of the application. In this paper, we examine a priority-driven, two-phase lock protocol called the read- or write-priority ceiling protocol. We show that this protocol is free of deadlock, and, in addition, a high-priority transaction can be blocked by lower priority transactions for, at most, the duration of a single embedded transaction. We then evaluate system performance experimentally.