Hi,

This is interesting. In your case, you have two components HelloworldDelegateComponent and HelloworldDelegateComponent2 that use the same java implementation class: sample.HelloworldImpl which is composite scoped. Now the question is how to interpret the following statement in the SCA java spec:

295 1.2.4.3. Composite scope
296 All service requests are dispatched to the same implementation instance for the lifetime of the containing 297 composite. The lifetime of the containing composite is defined as the time it becomes active in the runtime
298 to the time it is deactivated, either normally or abnormally.

There are two ways:

1) There is going to be one instance of sample.HelloworldImpl (A) that are shared by HelloworldDelegateComponent and HelloworldDelegateComponent2. Requests to both components will be dispatched to A.

2) There are going to be two instances of sample.HelloworldImpl (A & B), one for HelloworldDelegateComponent and the other for HelloworldDelegateComponent2. Request to HelloworldDelegateComponent will be dispatched to A while requests to HelloworldDelegateComponent2 will be dispatched B.

It seems that Tuscany works in the 1st way. We need clarifications from the spec group.

Thanks,
Raymond

From: Vamsavardhana Reddy
Sent: Wednesday, February 04, 2009 8:30 AM
To: [email protected]
Subject: Callback problem with COMPOSITE scoped implementation


I have a composite with three components as given below:

<composite xmlns="http://www.osoa.org/xmlns/sca/1.0";
          targetNamespace="http://sample";
          name="HelloworldDelegate">

   <component name="HelloworldXComponent">
       <implementation.java class="sample.HelloworldImpl"/>
   </component>

   <component name="HelloworldDelegateComponent">
       <implementation.java class="sample.HelloworldDelegateImpl"/>
       <service name="HelloworldDelegate">
<binding.ws uri="http://localhost:8080/tuscany/HelloworldDelegate"/>
       </service>
       <reference name="helloworld" target="HelloworldXComponent"/>
       <property name="salutation">Monsieur</property>
   </component>

   <component name="HelloworldDelegateComponent2">
       <implementation.java class="sample.HelloworldDelegateImpl"/>
       <service name="HelloworldDelegate">
<binding.ws uri="http://localhost:8080/tuscany/HelloworldDelegate2"/>
       </service>
       <reference name="helloworld" target="HelloworldXComponent"/>
       <property name="salutation">Mr.</property>
   </component>
</composite>

HelloworldImpl provides a Helloworld service and requires a HelloworldCallback callback service. HelloworldDelegateImpl provides HelloworldDelegate service and HelloworldCallback service. There are two components, namely HelloworldDelegateComponent (with salutation "Monsieur") and HelloworldDelegateComponent2 (with salutation "Mr."). Both these components invoke Helloworld service provided by HelloworldXComponent.
Both the implementations are COMPOSITE scoped.

When I use the HelloworldDelegate service from HelloworldDelegateComponent the output I see in the console is the following: HelloworldDelegateComponent: HelloworldDelegateImpl(sample.helloworlddelegatei...@28e2f1).sayHello: vamsi HelloworldXComponent: HelloworldImpl(sample.helloworldi...@10076aa).sayHello: vamsi HelloworldDelegateComponent: HelloworldDelegateImpl(sample.helloworlddelegatei...@28e2f1).whoIs: vamsi

and the message got back is "Hello Monsieur vamsi".
------------------------------
When I use the HelloworldDelegate service from HelloworldDelegateComponent the output I see in the console is the following: HelloworldDelegateComponent2: HelloworldDelegateImpl(sample.helloworlddelegatei...@146e74b).sayHello: vamsi HelloworldXComponent: HelloworldImpl(sample.helloworldi...@10076aa).sayHello: vamsi HelloworldDelegateComponent: HelloworldDelegateImpl(sample.helloworlddelegatei...@28e2f1).whoIs: vamsi

and the message got back is "Hello Monsieur vamsi". I was expecting "Hello Mr. vamsi".

Notice that in the second case, the callback service is called from HelloworldDelegateComponent instead of HelloworldDelegateComponent2. Is this the expected behaviour?
-----------------

If I make HelloworldImpl as STATELESS scoped (which is the default), then I am seeing that the callback service is invoked on the same component that is invoking the Helloworld service. The following is the output:

HelloworldDelegateComponent: HelloworldDelegateImpl(sample.helloworlddelegatei...@1c704a7).sayHello: vamsi HelloworldXComponent: HelloworldImpl(sample.helloworldi...@1af0f92).sayHello: vamsi HelloworldDelegateComponent: HelloworldDelegateImpl(sample.helloworlddelegatei...@1c704a7).whoIs: vamsi
Hello Monsieur vamsi

HelloworldDelegateComponent2: HelloworldDelegateImpl(sample.helloworlddelegatei...@61dec0).sayHello: vamsi HelloworldXComponent: HelloworldImpl(sample.helloworldi...@4f3d72).sayHello: vamsi HelloworldDelegateComponent2: HelloworldDelegateImpl(sample.helloworlddelegatei...@61dec0).whoIs: vamsi
Hello Mr. vamsi

What am I missing?

++Vamsi

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