On Fri, Aug 26, 2011 at 10:46 AM, ant elder <ant.el...@gmail.com> wrote:
> On Fri, Aug 26, 2011 at 9:13 AM, Simon Laws <simonsl...@googlemail.com> wrote:
>> snip...
>>> While we're on this subject, I happened to be wondering today whether
>>> @AsyncInvocation obligates the service implementation to use the async
>>> service interface? Obviously it makes the most sense to use them together,
>>> but is that required? As a service implementer, could I use
>>> @AsyncInvocation with the normal synchronous interface? This would mean the
>>> service implementation completes "inline" so to speak and has no need for a
>>> ResponseDispatch object. Since @AsyncInvocation is used, the SCA runtime is
>>> obligated to provide a suitable thread for a long-running request, and the
>>> binding still must support an asynchronous response. Effectively, it means
>>> the SCA runtime would do the ResponseDispatch call on behalf of the
>>> implementation at the completion of the method.
>>> I'm not terribly excited about supporting such a thing, but I didn't see
>>> anything in the spec that suggests either way whether it's allowed or
>>> disallowed.
>>> Greg
>>> On Thu, Aug 25, 2011 at 1:03 PM, Simon Laws <simonsl...@googlemail.com>
>>> wrote:
>>>>
>>
>> I agree Greg that the spec doesn't seem to outlaw it. It talks about
>> the mapping but doesn't seem to make it mandatory. I would suggest
>> that it's up to us to decide. My opening gambit would be to say we
>> don't support it in the first instance on the basis that if the user
>> went to the trouble to annotate a service with the asynInvocation
>> intent then presumably their intention was to exploit an async
>> invocation pattern. Just my 2c.
>>
>
> Section 6.4.3 in the assembly spec says "It is also possible for a
> service to set the asyncInvocation. intent when using an interface
> which is not marked with the asyncInvocation. intent. This can be
> useful when reusing an existing interface definition that does not
> contain SCA information." Its not terribly clear to me what that
> really implies but it does sound like it might be saying you can do
> what Greg is suggesting.
>
> ...ant
>
Good spot Ant but not sure what it means precisely in the context of
this question. I think you mean it's saying you can do either:
@AsyncInvocation
@Remotable
public interface HelloWorld {
public void helloAsync( String input, ResponseDispatch<String> handler
);
}
OR
@Remotable
public interface HelloWorld {
public String hello( String input);
}
<service name="HelloWorld" requires="asyncInvocation"/>
Although it's not explicit that the interface has to have any explicit
form. I can't see anything in JCAA about it.
Simon
--
Apache Tuscany committer: tuscany.apache.org
Co-author of a book about Tuscany and SCA: tuscanyinaction.com
