Re: DispatchPtr not releasing

Hi Morten,

the plot thickens.


> Hi Normand,
>
> Normand Mongeau wrote:
>
>> It's not easy to post code. I'll try to explain more in depth.
>>
>> DispatchPtr instances are kind of "smart" instances, because somewhere
>> deep
>> in the machinery of COM a Release gets sent when instances go out of
>> scope.
>> This is easily verified with the following: create a COM class, and
>> implement a FinalRelease method just to track when it gets called.  So if
>> you have code like this:
>>
>> instA = new A().
>>
>> when the instA variable goes out of scope the FinalRelease method will
>> get
>> called automatically (it's called by the Release() method).
>
> I will assume this is due to the reference count reaching 0. And if you
> call this code through Jawin, and don't call instA.close() it will
> happen from the finalize() of A (if it gets called).
>
> But it is unclear for me whether you actually calls close()?

I don't call close() explicitely, no.  If I do, the FinalRelease method of
my COM object gets called immediately instead of when the java instance goes
out of scope.

>
> I assume you have read the section
> http://jawinproject.sourceforge.net/jawinuserguide_dispatch.html#dispatchptr_usage

Yes I have, but it doesn't go into this level of detail.


>
>> My problem is that if I need to pass the A instance to another COM class,
>> the A never gets finalized.  This is also easy to verify with code like
>> this:
>>
>> instA = new A().
>> instB = new B().
>> instB->invokeSomeMethodPassingTheOtherInstance(instA).
>>
>> the finalization of the B instance will happen, but not the finalization
>> of
>> the A instance.
>>
>> This only happens through JAWIN.  It's as if an extra refCount was added
>> to
>> the A instance, thus not releasing it.
>
> I haven't verified whether you are correct. But what happens if your
> java code is extended to:
>
> instA = new A().
> instB = new B().
> instB->invokeSomeMethodPassingTheOtherInstance(instA).
>
> instB.close();
> instA.close();

When I add a call to instA.close() in the above scenario, the FinalRelease
method of my COM object doesn't get called.  I even tried several calls in
succession to instA.close() but none of them result in my FinalRelease
method being triggered.


>
> Hope this helps you.
> Best Regards
> Morten

It helps in pinpointing the problem I guess...

Thanks,

Normand