Please use this identifier to cite or link to this item:
Title: Dynamic ceiling priorities: A proposal for ada0y
Authors: Real, Jorge
Burns, Alan
Miranda, Javier 
Schonberg, Edmond
Crespo, Alfons
UNESCO Clasification: 3304 Tecnología de los ordenadores
Keywords: Calling Task
Dynamic Priority
Protected Object
Program Error
Protected Action
Issue Date: 2004
Journal: Lecture Notes in Computer Science 
Conference: 9th Ada-Europe International Conference on Reliable Software Technologies 
9th Ada-Europe International Conference on Reliable Software Technologies, Ada-Europe 2004 
Abstract: In Ada 95, the ceiling priority of a protected object is a static value that can only be assigned once, when the protected object is declared. This restriction coexists with the ability to dynamically change the priorities of tasks, which indeed is a flexible mechanism for programming adaptable real-time systems. Ceiling priorities being static, it is not possible to adequately implement the dynamic nature of multi-moded systems or systems scheduled with dynamic priorities. It is possible to work around this problem (e.g, by using the so-called ceiling of ceilings) but there is an added cost in terms of blocking times. The next revision of the Ada 95 Standard, known as Ada 0Y, is considering the inclusion of dynamic ceiling priorities in the language. This paper presents the arguments for dynamic ceilings and discusses the approach proposed by the International Real-Time Ada Workshop consensus group. An experimental implementation is also discussed in order to evaluate the impact of this feature on the GNAT Ada compiler and run-time system which, in a nutshell, has turned out to be very low.
ISBN: 3540220119
ISSN: 0302-9743
DOI: 10.1007/978-3-540-24841-5_21
Source: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)[ISSN 0302-9743],v. 3063, p. 261-272
Appears in Collections:Actas de congresos
Show full item record


checked on Nov 26, 2023


checked on Jul 9, 2023

Page view(s)

checked on May 13, 2023

Google ScholarTM




Export metadata

Items in accedaCRIS are protected by copyright, with all rights reserved, unless otherwise indicated.