Model-Driven Evolution of Software Architectures - Software and ...
Model-Driven Evolution of Software Architectures - Software and ...
Model-Driven Evolution of Software Architectures - Software and ...
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116 Chapter6. ConformanceCheckingII<br />
invocations<strong>and</strong>fieldaccessestargetedatclasseswealsoimplemented.<br />
BecauseJavaMLdiscardscomments,weuseasimplePerl-scripttoretrieve<br />
@moduleclauses<strong>and</strong>generateanXML-documentconsisting<strong>of</strong> elements.Theprojection<strong>of</strong>thisdocument<br />
asXMLmodelservesasadditionalsourcemodeltoatransformationthat<br />
createsmodulesthatarecomposed<strong>of</strong>theclassescreatedbytheprevious<br />
transformation.Afinal(refining)modeltransformationliftsthefieldaccess<br />
<strong>and</strong>calldependenciestothelevel<strong>of</strong>modulesasUsesrelations.<br />
NexttotheJavasourcecode,thearchitecturalusesview<strong>of</strong>Figure6.3(b)<br />
onpage107wasanotherinputforourCCS,representingthe’as-designed’<br />
architecture.Population<strong>of</strong>aMADLmodelfromthisUMLmodelisstraightforwardbecause<strong>of</strong>theuse<strong>of</strong>stereotypestodenotemodules<strong>and</strong>usesrelations.<br />
Theresult(forimplementation<strong>and</strong>architecture)isrepresentedasa<br />
directedgraphasshowninFigure6.7.Here,boxesrepresentmodules,<strong>and</strong><br />
arrowsrepresentusesdependencies.Itcanbeseenthatthemodelderived<br />
fromtheimplementationconsists<strong>of</strong>twounconnectedsubgraphs. Infact,<br />
onesubgraphcorrespondstothepart<strong>of</strong>theimplementationdeployedon<br />
thePC,theothertothepartdeployedonthemicrocontroller. Obviously,<br />
nodirectmethodinvocations<strong>and</strong>fieldaccessesarepossiblebetweenthose<br />
parts.<br />
C&CViews Components,ports,connectors,<strong>and</strong>rolesarearchitecturalconceptsthatmayormaynothaveexplicitcounterpartsinthedevelopment<br />
viewsorimplementation.Theimplementationisnotmerelyarefinement<br />
<strong>of</strong>thesearchitecturalelementsasinthecase<strong>of</strong>developmentviews. This<br />
makesthemappingbetweenthearchitecturalC&Cviews<strong>and</strong>implementationconstructsindirect<strong>and</strong>moredifficult.Themainconcern<strong>of</strong>theC&CviewinFigure6.3(a)onpage107isconcurrency.<br />
Forsuchaviewthecomponentscorrespondtoimplementation<br />
mechanismsforconcurrency<strong>and</strong>parallelism,suchasprocesses,threads<br />
<strong>and</strong>tasks.Forexampleinthecase<strong>of</strong>asystemimplementedinJava,these<br />
componentscorrespondtothreads.Similarly,connectors,inthatcase,are<br />
abstractions<strong>of</strong>themechanismsthatallowthesethreadstointeract,forinstanceinter-process-communicationmechanisms,remote-procedurecalls,<br />
orshared-data.<br />
CreatingaC&Cviewfromstaticsourcesisveryapplicationspecific;it<br />
dependsonconventionsforimplementing,forinstance,concurrency<strong>and</strong><br />
communicationmechanisms.InthiscasewewanttoreconstructaCPADL<br />
modelrepresentingaset<strong>of</strong>communicatingprocesses. Assaid,inJava<br />
thistype<strong>of</strong>componentscorrespondstothreads. Javathreadsareclasses<br />
withamain-methodorclassesthatextendtheJava Threadclass. Inthis
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