Title :
Optimistic synchronization in distributed shared memory
Author :
Hermannsson, Gudjon ; Wittie, Larry
Author_Institution :
Renaissance Technol. Corp., Stony Brook, NY, USA
Abstract :
Introduces optimistic lock synchronization using the group write consistency (GWC) model. GWC guarantees strict ordering of all shared writes in a processor group. In optimistic synchronization, if a lock-requesting processor can assume that the lock is free, execution of mutually exclusive code starts immediately. A wrong assumption results in rollback. Shared variable updates remain in the group until the lock manager grants the lock to the requesting processor. By evaluating the time needed for three processors to execute mutually exclusive code, GWC can out-perform weak, release, and even entry consistency. Simulations of task management using exclusive access to a shared queue, also show much faster mutual exclusion with GWC. Optimistic mutual exclusion may further halve total delays in accessing shared resources
Keywords :
delays; distributed memory systems; resource allocation; shared memory systems; synchronisation; distributed shared memory; entry consistency; exclusive access; group write consistency model; lock-requesting processor; mutually exclusive code; optimistic lock synchronization; processor group; release consistency; rollback; shared queue; shared resource access delays; shared variable updates; shared writes; strict ordering; task management simulation; weak consistency; Computational modeling; Computer simulation; Contracts; Delay estimation; Distributed computing; Optical wavelength conversion; Performance evaluation; Programming profession; Resource management; Superconducting logic circuits;
Conference_Titel :
Distributed Computing Systems, 1994., Proceedings of the 14th International Conference on
Conference_Location :
Pozman
Print_ISBN :
0-8186-5840-1
DOI :
10.1109/ICDCS.1994.302435
