This section describes modeling the Quoter application using PICML. If you have trouble producing a functioning model from this tutorial, please see the, pre-built Quoter model which is provided for your reference. This model contains all elements created as part of this tutorial.
The PICML paradigm is designed for the OMG Deployment & Configuration (D&C) specification (ptc/2003-07-08), so the modeling process is straightforward if you are familiar with the specification. Please see the DAnCE project for more information. For those who hate specification (including me, :-)), an overview of D&C and as well as a tutorial of D&C and CCM can help to reduce the learning curve. (Thanks to Sowayan, Abdulah for pointing this out). In addition, it is also helpful to read through Chapter 32 of TAO's Developer's Guide 1.4a (CIAO and CCM) which thoroughly describes the various descriptors required for a component (*.iad, *.ccd, *.cid, etc).
The complete PICML Quoter model consists of modeling elements distributed across various folders. If you used idl_to_picml to generate the initial model, you will see that it has created all these folders and some of the tedious boilerplate modeling for us. The rest of the section will explain the purpose of each folder as well as the modeling entities contained in these folders. We will also show how to model some of the folders that have to be done by hand.
This folder contains implementation artifacts associated with components. idl_to_picml has created these artifacts for us, with their dependency relationships correctly captured. Figure 4 shows the Implementation Artifacts for Broker.
This folder contains models that describe the implementations of component interfaces. In the Quoter example, we will have two monolithic component implementations - named StockDistributorImplementation and StockBrokerImplementation - and an assembly component implementation named StockQuoter, which is an assembly of StockDistributorImplementation and StockBrokerImplementaion. idl_to_picml has created the monolithic component implementations for us, as shown in figure 5 for example, but we have to specify the connections between them in order to construct a Quoter system.
Assembly components provide a boundary for the composition of
monolithic components and even other assemblies. Assembly components do
not provide actual implementations for their interface, it is a virtual
component that delegates its ports and attributes to one or more of the
entities it contains. There are slight differences between modeling an
assembly and modeling a monolithic component. Since the assembly is a
virtual component, it is not necessary to model a MonolithicImplementation
.
Instead, instances of other components are placed
within the assembly and connected. Let's try to assemble the StockQuoter.
InterfaceDefinitions
,
then expand the InterfaceDefinitions/
Broker, then InterfaceDefinitions/
Broker/ Stock until the interface definition
of StockBroker shows. While expanding the tree,
always keep the "StockQuoter"
<<ComponentAssembly>> window open. Then
drag MyQuoter/InterfaceDefinitions/Broker/Stock/StockBroker
in the browser to the "StockQuoter"
<<ComponentAssembly>> window while pressing
ALT key. Repeat the same steps for MyQuoter/InterfaceDefinitions/Distributor/Stock/StockDistributor
,
and you will see two instances of component interfaces have been
created as shown in Figure 6 (the black line in the figure only
indicates .mapping)MyQuoter/ComponentImplementations/StockBroker
Implementation/StockBrokerMonolithicImpl.
Refer the <<ComponentRef>> Broker
to MyQuoter/InterfaceDefinitions/Broker/Stock/StockBroker
.
To create a reference in GME, simply drag the tree node in the Browser
"into" the reference model. For example, you should drag the tree node MyQuoter/ComponentImplementations/StockBroker
Implementation/StockBrokerMonolithicImpl
into <<ComponentImplementationReference>> Broker.
Check GME manual(tutorials) for more information./ComponentImplementations/StockQuoter/StockQuoter
MyQuoter/ComponentPackage/StockQuoter/StockQuoter
(Not <<ComponentImplementationReference>>
MyQuoter/ComponentPackage/StockQuoter/StockQuoter!)
Quoter/PackageConfiguration/Default/Default
MyQuoter/Targets/Domain/Broker
and MyQuoter/Targets/Domain/Distributor
respectivelyMyQuoter/ComponentImplementations/StockQuoterImplementation/StockQuoter/StockBroker
and MyQuoter/ComponentImplementations/StockQuoterImplementation/StockQuoter/StockDistributor
respectively. Note that the
<<ComponentRef>> in DeploymentPlan is not
referring to the interface, but rather the actual instance of the
implementation.Now move your cursor to
<<ComponentRef>>
StockDistributor, and left-click it, so that it looks like Figure 12.
This operation associates StockDistributor
component to the <<CollocationGroup>>
running on Distributor node. To do the same with
Broker, just right-click on another
<<CollocationGroup>>, and left-click on
StockBroker <<CollocationGroup>> which is
highlighted.
Up to this point, we are basically done with the modeling part. Before we generate anything from this model though, please DO remember to check the constraints of the model as we mentioned earlier.
After we are done with the modeling, the
flattened_deploymentplan interpreter that comes along with PICML will
help us to generate a flattened_deploymentplan.cdp file. Please make
sure you generate this file to MyQuoter/descriptors. Note that to get the example working,a Node Map file should be created to map logical nodes to NodeManager object references,e.g:
DistributorNode corbaloc:iiop:localhost:30000/NodeManager
BrokerNode corbaloc:iiop:localhost:40000/NodeManager