The usage of @Callback in Vamsi's case should be supported too by the spec. 
It's probably a Tuscany bug that has a staled cache based on the 
HelloworldXComponent. Vamsi, do you have a test case that we can try?

Thanks,
Raymond 


From: Simon Laws 
Sent: Friday, February 06, 2009 6:33 AM
To: [email protected] 
Subject: Re: Callback problem with COMPOSITE scoped implementation





On Fri, Feb 6, 2009 at 2:26 PM, Vamsavardhana Reddy <[email protected]> wrote:




  On Fri, Feb 6, 2009 at 5:07 PM, Simon Laws <[email protected]> wrote:




    On Thu, Feb 5, 2009 at 1:04 AM, Raymond Feng <[email protected]> wrote:

      Hi,

      I realized that I misunderstood the problem after reading your case again 
(where the system hash id for the objects are shown).  Sorry for the confusion.

      1) Tuscany's composite scope management seems to be correct. 

      1. HelloworldDelegateComponent is using instance A of 
HelloworldDelegateImpl
      2. HelloworldDelegateComponent2 is using instance B of 
HelloworldDelegateImpl
      3. HelloworldXComponent is using instance C of HelloworldImpl.

      2) Tuscany resolves the target for a callback based on the SCA context 
for the incoming invocation. That's why it works if the scope for 
HelloworldXComponent is STATELESS.

      3) When HelloworldXComponent is composite scoped, there is one instance. 
Tuscany runtime probably has some cache that keep the resolved callback. And it 
becomes staled when the 2nd call is coming from a different component. We'll 
need to look into the code to fix that.

      Vamsi, can you attach your test case to a JIRA?

      Thanks,
      Raymond


      From: Raymond Feng 
      Sent: Wednesday, February 04, 2009 1:03 PM
      To: [email protected] 
      Subject: Re: Callback problem with COMPOSITE scoped implementation


      Sorry, I took the wrong class name. But the story stays. 

      In this case is that the "salutation" property is injected. It is 
configured to two different values by the two components. Since Tuscany 
interprets the spec in the 1st way, and there is a single java object 
(sample.HelloworldDelegateImpl) , the field got injected twice and the later 
one overrode the first one. That's why you only see the same salutation.

      Thanks,
      Raymond 


      From: Vamsavardhana Reddy 
      Sent: Wednesday, February 04, 2009 12:47 PM
      To: [email protected] 
      Subject: Re: Callback problem with COMPOSITE scoped implementation


      Raymond,

      HelloworldDelegateComponent and HelloworldDelegateComponent2 are using 
the implementation class sample.HelloworldDelegateImpl. Both these components 
are invoking a service from HelloworldXComponent which uses implementation 
class sample.HelloworldImpl.  Each of these components are using a single 
instance per component of the respective implementation classes through out the 
scope of the composite. Let us say
      1. HelloworldDelegateComponent is using instance A of 
HelloworldDelegateImpl
      2. HelloworldDelegateComponent2 is using instance B of 
HelloworldDelegateImpl
      3. HelloworldXComponent is using instance C of HelloworldImpl.

      The problem is that
      a) when A is invoking service from C, C.callback should be injected with 
the callback service provided by A and
      b) when B is invoking service from C, C.callback should be injected with 
the callback service provided by B

      Even though it is one instance of HelloworldImpl that is used, the 
callback field should keep changing depending on who is invoking the service.  
Don't know if it is feasible.


      On Thu, Feb 5, 2009 at 12:49 AM, Raymond Feng <[email protected]> wrote:

        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 





      -- 
      Vamsi



    Isn't it just that the the @Callback is injected once when the COMPOSITE 
scoped component is created that is causing the caching of the callback and 
hence the problem in this scenario.

    What happens if you use RequestContext.getCallback()?
  With RequestContext.getCallback(), it is working as expected.
   


    Simon




  -- 
  Vamsi


Hi Vamsi

So what you mean by "working as expected." is that the callback goes to the 
client that originates each call as opposed to the first client that is 
injected when you use the inject callback?

If yes this underlines the fact that Tuscany has the right information and is 
able to create the right proxy. It's just not able to inject it into a 
component whose scope extends over more than one call. 

Simon

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