Computer architecture is about to undergo, if not another revolution, then a vigorous shaking-up. The major chip manufacturers have, for the time being, simply given up trying to make processors run faster. Instead, they have recently started shipping ``multicore'' architectures, in which multiple processors (cores) communicate directly through shared hardware caches, providing increased concurrency instead of increased clock speed.
As a result, system designers and software engineers can no longer rely on increasing clock speed to hide software bloat. Instead, they must somehow learn to make effective use of increasing parallelism. This adaptation will not be easy. Conventional synchronization techniques based on locks and conditions are unlikely to be effective in such a demanding environment. Coarse-grained locks, which protect relatively large amounts of data, do not scale, and fine-grained locks introduce substantial software engineering problems.
Transactional memory is a computational model in which threads synchronize by optimistic, lock-free transactions. This synchronization model promises to alleviate many (perhaps not all) of the problems associated with locking, and there is a growing community of researchers working on both software and hardware support for this approach. This talk will survey the area, with a focus on open research problems.
Download slides for today's talk in PDF format.
About the speaker:
Maurice Herlihy received an A.B. degree in Mathematics from Harvard University and a Ph.D. degree in Computer Science from MIT. He has been an
Assistant Professor in the Computer Science Department at Carnegie Mellon University, a member of the research staff at Digital Equipment
Corporation's Cambridge (MA) Research Lab, and a consultant for Sun Microsystems. He is now a Professor of Computer Science at Brown University.
Prof. Herlihy's research centers on practical and theoretical aspects of multiprocessor synchronization, with a focus on wait-free and lock-free synchronization. His 1991 paper "Wait-Free Synchronization" won the 2003 Dijkstra Prize in Distributed Computing, and he shared the 2004 Goedel Prize for his 1999 paper "The Topological Structure of Asynchronous Computation." He is a Fellow of the ACM.