A fast general-purpose hardware synchronization mechanism

Abstract

One way to reduce the overhead of concurrency control m a multiprocessor transaction processing system is to implement an underlying synchromzation mechanism or a simple global concurrency control dlrectly in hardware The problem with this approach is that a strong comnutment may then be made to a particular synchromzatlon protocol, and so the resulting hardware mechanism may be useful m only a very narrow range of systems A solution is possible using a table-dnven approach However, a straightforward table-driven approach is lmpractlcal due to the extremely large table sEes required for many protocols It is shown here that this problem can be solved by reducing the table sizes required by making use of the processor symmetry that occurs in most systems The resulting algorithm for a table-dnven synchromzation mechanism is not only general-purpose but also extremely fast An example hardware unplementation of tis algonthm is presented, and practical expenence using this approach is described. © 1985, ACM. All rights reserved.