We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
Published online by Cambridge University Press: 10 December 2009
The last few chapters have demonstrated the extensive set of facilities that Ada 2005 provides for the support of real-time programming. The expressive power of the full language is clearly more comprehensive than any other mainstream engineering language. There are, however, situations in which a restricted set of features are desirable. This chapter looks at ways in which certain restrictions can be identified in an Ada program. It then describes in detail the Ravenscar profile, which is a collection of restrictions aimed at applications that require very efficient implementations, or have high-integrity requirements, or both. This chapter also includes a discussion of the metrics identified in the Real-Time Systems Annex.
Restricted tasking and other language features
Where it is necessary to produce very efficient programs, it is useful to have runtime systems (kernels) that are tailored to the particular needs of the program actually executing. As this would be impossible to do in general, the Ada language defines a set of restrictions that a run-time system should recognise and ‘reward’ by giving more effective support. The following restrictions are identified by the pragma called Restrictions, and are checked and enforced before run-time. Note however, that there is no requirement on the run-time to tailor itself to the restrictions specified.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.
