Capability

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-	XXX copy in a well-written existing definition here	+	== Definition ==
-	A capability is a reference which combines designation with [[authority]].	+	Capability is an unforgeable designation of an [[subject, object, operation and permission|object]] together with a permission to make some set of operations with a given object.
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-	Designation is ...	+
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-	Authority is ...	+
	== Examples ==		== Examples ==
-	* Object references in object-oriented programming languages, provided that they have encapsulation and do not have other ways to acquire references (XXX explain or move to page on Object-capabilities)	+	* Designations of objects in [[E]]. Those who hold these capabilities have the permission to invoke any method supported by the designated object.
-	* capabilities, or "keys", in [[capability operating systems]] such as [[KeyKos]], [[CapROS]], or [[Coyotos]]	+	* Designations of functions and procedures in [[Emily]]. Those who hold these capabilities have the permission to call designated functions or procedures.
-	* an Actor address + an facet identifier? (XXX what is this?)	+	* Designations of channels in [[Pict]]. Those who hold these capabilities may have a permission to make send and/or receive operations with the designated channel.
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-	== See also ==	+
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-	(XXX improve this section)	+
-		+
-	See [http://www.eros-os.org/essays/capintro.html What is a Capability, Anyway?] for a partisan explanation of what capabilities actually are.	+
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-	See also [http://www.erights.org/elib/capability/overview.html Overview: Capability Computation]	+
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-	{{stub}}	+

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Revision as of 09:52, 10 July 2009

Definition

Capability is an unforgeable designation of an object together with a permission to make some set of operations with a given object.

Examples

• Designations of objects in E. Those who hold these capabilities have the permission to invoke any method supported by the designated object.
• Designations of functions and procedures in Emily. Those who hold these capabilities have the permission to call designated functions or procedures.
• Designations of channels in Pict. Those who hold these capabilities may have a permission to make send and/or receive operations with the designated channel.