Skip Navigation

The Computer Journal 1979 22(2):142-145; doi:10.1093/comjnl/22.2.142
© 1979 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 arrowRequest Permissions
Google Scholar
Right arrow Articles by Silberschatz, A.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

On the safety of the IO primitive in Concurrent PASCAL*

A. Silberschatz §

Department of Mathematical Sciences, The University of Texas at Dallas Richardson, Texas, USA

In Concurrent PASCAL the peripheral device disc is viewed as an array of pages which can only be accessed via the standard procedure IO. On of the input parameters to the procedure is an index I to indicate which page in the array has to be accessed. The IO procedure can be invoked from any system module and the index I can be set arbitrarily by that module. Hence, one system module can jeopardise the integrity of a system written in this language.

This paper proposes an extension to Concurrent PASCAL to resolve this difficulty. In particular, we define a new concept scope which specifies the names of the program components which can declare an instance of a particular type. Given this concept and the program component manager, we devise a mechanism which will be shown to be consistent with the design goals of Concurrent PASCAL and which can be used to enforce processes to use the IO procedure with the index I set to only those pages which they have a legal right to access.

Received January 1978.

* An early version of this paper was presented in the IEEE Computer Software and Application Conference, Chicago 1977

§ This work was partially supported by the National Science Foundation under Grant No. MCS 7702463

Department of Mathematical Sciences, The University of Texas at Dallas Richardson, Texas 75080, USA


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.