Accession Number : ADA187823

Title :   The Roll Back Chip: Hardware Support for Distributed Simulation Using Time Warp.

Descriptive Note : Technical rept.,

Corporate Author : UTAH UNIV SALT LAKE CITY DEPT OF COMPUTER SCIENCE

Personal Author(s) : Fujimoto, Richard M ; Tsai, Jya-Jang ; Gopalakrishnan, Ganesh

PDF Url : ADA187823

Report Date : Oct 1987

Pagination or Media Count : 29

Abstract : Distributed simulation offers an attractive means of meeting the high computational demands of discrete event simulation programs. The Time Wrap mechanism has been proposed to ensure correct sequencing of events in distributed simulation programs without blocking processes unnecessarily. However, the overhead of state saving and rollback in Time Wrap is one obstacle that may severely degrade performance. A special purpose hardware component, the rollback chip (RBC), is proposed to manage the state of a processor and provide an efficient rollback mechanism within a node of a parallel computer. The chip may be viewed as a special purpose memory management unit that lies on the data path between processor and memory. The algorithm implemented by the rollback chip is described, as well as extensions to the basic design. Implementation of the chip is briefly discussed. In addition to distributed simulation, the rollback chip may be used in other applications using the Time Wrap mechanism, notably distributed database concurrency control.

Descriptors :   *ALGORITHMS, *CHIPS(ELECTRONICS), *DISTRIBUTION, *PARALLEL PROCESSORS, *SIMULATION, BLOCKING, COMPUTERS, DATA BASES, DATA TRANSMISSION SYSTEMS, PATHS, ROLL, TIME, WINDING

Subject Categories : Computer Programming and Software
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE