Skip Navigation

The Computer Journal 1996 39(5):361-373; doi:10.1093/comjnl/39.5.361
© 1996 by British Computer Society
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Wellings, A. J.
Right arrow Articles by Burns, A.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Programming Replicated Systems in Ada 95

A. J. Wellings * and A. Burns *

Real-Time Systems Research Group, Department of Computer Science, University of York, York YO1 5DD, UK

This paper considers the programming of passive (cold and warm standbys) and active replicated systems in Ada 95. We show that it is relatively easy to develop systems which act as standbys using the facilities provided by the language and the Distributed Systems Annex. Arguably, active replication in Ada 95 can be supported in a manner which is transparent to the application. However, this is implementation-dependent, requires a complex distributed consensus algorithm (or a carefully chosen subset of the language to be used) and has little flexibility. We therefore consider two extensions to the Distributed Systems Annex to help give the application programmer more control. The first is a via a new categorization pragma which specifies that a RCI package can be replicated in more than one partition. The second is through the introduction of a coordinated type which has a single primitive operation. Objects which are created from extensions to coordinated types can be freely replicated across the distributed system. When the primitive operation is called, the call is posted to all sites where a replica resides, effectively providing a broadcast (multicast) facility. We also consider extensions to the partition communication subsystem which implement these new features.

Received April 4, 1996. revised July 3, 1996.

* Real-Time Systems Research Group, Department of Computer Science, University of York, York YO1 5DD, UK Email: andy{at}minster.york.ac.uk


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.