This HTML5 document contains 36 embedded RDF statements represented using HTML+Microdata notation.

The embedded RDF content will be recognized by any processor of HTML5 Microdata.

Namespace Prefixes

Prefix	IRI
dcterms	http://purl.org/dc/terms/
dbo	http://dbpedia.org/ontology/
foaf	http://xmlns.com/foaf/0.1/
n16	http://developer.symbian.org/wiki/index.php/
n19	https://global.dbpedia.org/id/
yago	http://dbpedia.org/class/yago/
dbt	http://dbpedia.org/resource/Template:
rdfs	http://www.w3.org/2000/01/rdf-schema#
freebase	http://rdf.freebase.com/ns/
rdf	http://www.w3.org/1999/02/22-rdf-syntax-ns#
owl	http://www.w3.org/2002/07/owl#
n18	http://dbpedia.org/resource/Asynchronous_I/
wikipedia-en	http://en.wikipedia.org/wiki/
dbc	http://dbpedia.org/resource/Category:
prov	http://www.w3.org/ns/prov#
dbp	http://dbpedia.org/property/
xsdh	http://www.w3.org/2001/XMLSchema#
gold	http://purl.org/linguistics/gold/
wikidata	http://www.wikidata.org/entity/
dbr	http://dbpedia.org/resource/

Statements

Subject Item

dbr:Active_object_(Symbian_OS)

rdf:type

yago:Content105809192 yago:Concept105835747 yago:Abstraction100002137 yago:Cognition100023271 yago:WikicatProgrammingConstructs yago:Idea105833840 yago:PsychologicalFeature100023100

rdfs:label

Active object (Symbian OS)

rdfs:comment

An active object framework is a callback-based form of multitasking for computer systems. Specifically, it is a form of cooperative multitasking and is an important feature of the Symbian operating system. When the asynchronous task completes, the operating system identifies the thread containing the requesting active object, and wakes it up. An "active scheduler" in the thread identifies the object that made the request, and passes control back to that object.

dcterms:subject

dbc:Symbian_OS

dbo:wikiPageID

784730

dbo:wikiPageRevisionID

831362259

dbo:wikiPageWikiLink

dbr:Object_(computer_science) dbr:Operating_system dbr:Semaphore_(programming) dbr:Computer_multitasking dbc:Symbian_OS dbr:Thread_(computer_science) dbr:Callback_(computer_science) dbr:Short_message_service dbr:Cooperative_multitasking dbr:Symbian_OS n18:O dbr:Synchronization_(computer_science) dbr:Symbian

dbo:wikiPageExternalLink

n16:Active_Objects_%28Fundamentals_of_Symbian_C++%29

owl:sameAs

freebase:m.03c45z wikidata:Q4677572 n19:4Kz8t

dbp:wikiPageUsesTemplate

dbt:About dbt:Operating-system-stub

dbo:abstract

An active object framework is a callback-based form of multitasking for computer systems. Specifically, it is a form of cooperative multitasking and is an important feature of the Symbian operating system. Within the framework, active objects may make requests of asynchronous services (e.g. sending an SMS message). When an asynchronous request is made, control is returned to the calling object immediately (i.e. without waiting for the call to complete). The caller may choose to do other things before it returns control back to the operating system, which typically schedules other tasks or puts the machine to sleep. When it makes the request, the calling object includes a reference to itself. When the asynchronous task completes, the operating system identifies the thread containing the requesting active object, and wakes it up. An "active scheduler" in the thread identifies the object that made the request, and passes control back to that object. The implementation of active objects in Symbian is based around each thread having a "request semaphore". This is incremented when a thread makes an asynchronous request, and decremented when the request is completed. When there are no outstanding requests, the thread is put to sleep. In practice there may be many active objects in a thread, each doing its own task. They can interact by requesting things of each other, and of active objects in other threads. They may even request things of themselves. This is an implementation of a very old idea that was developed to handle software interruptions in the 70s. The operating system was acting as the first object and the peripheral as the second one.

gold:hypernym

dbr:Form

prov:wasDerivedFrom

wikipedia-en:Active_object_(Symbian_OS)?oldid=831362259&ns=0

dbo:wikiPageLength

2214

foaf:isPrimaryTopicOf

wikipedia-en:Active_object_(Symbian_OS)