[omniORB] _narrow problems with VAC++ 5.0 on AIX

[Peter Ledbrook]

Hi,

Much as I would like to give up supporting AIX, we are not allowed to.
So, can anyone help with this problem.

Part of an interface structure I have is:

    ICapeNumericSolverComponent
    ICapeNumericLAComponent : ICapeNumericSolverComponent
    ICapeNumericLASystemFactory : ICapeNumericLAComponent

Now, the client gets an object reference from a shared library that it
loads in. This object reference is an implementation of the
ICapeNumericLASystemFactory interface and has a repoID of:

  "IDL:ICapeNumericLASystemFactory:1.0"

The client then tries to narrow this to an
ICapeNumericSolverComponent_ptr with a repoID of:

  "IDL:ICapeNumericSolverComponent:1.0"

This narrow fails though, and returns a _nil object reference. Stepping
through the code of _realNarrow I see the following behaviour:

void*
omniObject::_realNarrow(const char* repoId)
{
  void* target = _widenFromTheMostDerivedIntf(repoId);  <<<<< This
returns 0x00000000

  if (target) {
    // Must increment the reference count because the return value
    // will be freed by CORBA::release().
    omni::objectDuplicate(this);
  }
  else {
    if (is_proxy()) {     <<<<< This fails, so drops out of this if
block
      // Either:
      //  1. This proxy object was created for an object type that we do
not
      //     have authoritative answer to its inheritance relation.
      //  2. The object's actual most derived type has been changed to a

      //     more derived type after this object reference is generated.

      //     Since the type ID in the IOR is only considered as a hint,
      //     we cannot give up without asking the object about it.
      // Use _is_a() to query the object to find out if <repoId> is the
      // IR repositoryID of a base type of this object.
      if (_real_is_a(repoId)) {
        // OK, it is a base type
        try {
          omniObject* omniobj = omni::createObjRef(NP_IRRepositoryId(),

repoId,

iopProfiles(),0);
          target = omniobj->_widenFromTheMostDerivedIntf(repoId);
        }
        catch(...) {}
        }
      }
    }
    return target;      <<<<< Returns 0x00000000
}

This only happens on AIX and I have no idea why. I'm not particularly au
fait with the mechanism for checking the inheritance hierarchy, so has
anyone else come across this or know a solution? This seems to be the
cause of a bug in our software which stops it working at all :-/

As usual, any help would be much appreciated,

Peter

--
Product Development Engineer
Process Systems Enterprise Ltd.

Bridge Studios,
107a Hammersmith Bridge Road,
London
W6 9DA

Tel: +44 20 8563 0888   Fax: +44 20 8563 0999

mailto:p.ledbrook@psenterprise.com
website: http://www.psenterprise.com