A Scalable Shared Queue on a Distributed Memory Machine

• Published in: Computer journal Vol. 39; no. 6; pp. 483 - 495
• Main Author: Nash, J. M.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.01.1996
• Subjects: Applied sciences; Computer science; control theory; systems; Computer systems and distributed systems. User interface; Exact sciences and technology; Language processing and microprogramming; Memory and file management (including protection and security); Memory organisation. Data processing; Software; Algorithm performance; Concurrency; Semantics; Distributed computer systems; Resource sharing; Synchronization; Queueing theory; Shared memory
• ISSN: 0010-4620; 1460-2067
• DOI: 10.1093/comjnl/39.6.483

The emergence of low latency, high throughput routers means that network locality issues no longer dominate the performance of parallel algorithms. One of the key performance issues is now the even distribution of work across the machine, as the problem size and number of processors increase. This paper describes the implementation of a highly scalable shared queue, supporting the concurrent insertion and deletion of elements. The main characteristics of the queue are that there is no fixed limit on the number of outstanding requests and the performance scales linearly with the number of processors (subject to increasing network latencies). The queue is implemented using a general-purpose computational model, called the WPRAM. The model includes a shared address space which uses weak coherency semantics. The implementation makes extensive use of pairwise synchronization and concurrent atomic operations to achieve sealable performance. The WPRAM is targeted at the class of distributed memory machines which use a scalable interconnection network.