Pessimistic Concurrency Control and Versioning to Support Database Pointers in Real-Time Databases

In this paper we present a concurrency control algorithm that allows co-existence of soft real-time, relational database transactions, and hard real-time database pointer transactions in real-time database management systems. The algorithm uses traditional pessimistic concurrencycontrol (i.e. locking) for soft transactions and versioning for hard transactions to allow them to execute regardless of any database lock. We provide formal proof that the algorithm is deadlock free and formally verify that transactions have atomic semantics. We also present an evaluation that demonstrates significant benefits for both soft and hard transactions when our algorithm is used. The proposed algorithm is suited for resource-constrained safety critical, real-time systems that have a mix of hard real-time control applications and soft real-time management, maintenance, or user-interface applications.

• Type: Conference
• Year: 2004
• Where: ECRTS
• Authors: Dag Nyström, Mikael Nolin, Aleksandra Tesanovic, Christer Norström, Jörgen Hansson
• Keywords: Algorithm, ECRTS 2004, Embedded Systems, Hard Real-time, Soft Real-time