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  1. OMG Issue

CORBA3 — conflict between CORBA specification and C++ mapping (_this method

  • Key: CORBA3-46
  • Legacy Issue Number: 4823
  • Status: closed  
  • Source: Anonymous
  • Summary:

    I think that there is conflict between CORBA specification and C++ mapping (_this method). May be it relates both to CORBA specification and C++ mapping.

    The Portable Object Adapter chapter of CORBA 2.6 specification 11.2.7 Implicit Activation (last paragraph - before Note)

    If the POA has the MULTIPLE_ID policy, the servant_to_reference and servant_to_id operations will always perform implicit activation, even if the servant is already associated with an Object Id. The behavior of language mapping operations in the MULTIPLE_ID case is specified by the language mapping. For example, in C++, the _this() servant member function will not implicitly activate a MULTIPLE_ID servant if the invocation of _this() is immediately within the dynamic context of a request invocation directed by the POA to that servant; instead, it returns the object reference used to issue the request.

    If I am right, author thinks that _this operation can be called on servant (related to POA with MULTIPLE_ID policy) multiple times (and it will not raise PortableServer::WrongPolicy exception).

    But C++ mapping provides the following semantics of _this:

    1.36.5 Skeleton Operations 3. ... This requires the POA with which the servant was activated to have been created with the UNIQUE_ID and RETAIN policies. If the POA was created with the MULTIPLE_ID or NON_RETAIN policies, the PortableServer::WrongPolicy exception is thrown.

    Moreover CORBA specification provides the following semantics for servant_to_reference method: servant_to_reference 2. If the POA has both the RETAIN and the IMPLICIT_ACTIVATION policy and either the POA has the MULTIPLE_ID policy or the specified servant is not active, the servant is activated using a POA-generated Object Id and the Interface Id associated with the servant, and a corresponding object reference is returned.

    If I am right, _this and servant_to_reference are very close by their semantics (sometimes _this can be implemented using servant_to_reference invocation on appropriate POA). That's why I think that C++ mapping conflicts with CORBA specification.

    Could you please provide some explanation about this problem (even if I am not right).

  • Reported: CORBA 2.6 — Mon, 4 Feb 2002 05:00 GMT
  • Disposition: Resolved — CORBA 3.0.2
  • Disposition Summary:

    see above, close no change

  • Updated: Fri, 6 Mar 2015 20:58 GMT