Re: DCOM to DCOM call fails with 80040200

From: Alexander Nickolov (agnickolov_at_mvps.org)
Date: 09/16/04 

Date: Thu, 16 Sep 2004 10:26:43 -0700

So is it that AtlAdvise returns this eror? Or you called
IConnectionPoint::Advise manually? In any other situation
the code would mean something different - depending on
the interface being called. 

-- 
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================
"Sanjay Dattatri" <sdattatri@vsnl.com> wrote in message 
news:2c3fbb74.0409160305.657445ab@posting.google.com...
>I thought this error was returned from AtlAdvise(). MSDN says
> +++++++++++++++++++++++++++
> CONNECT_E_NOCONNECTION Error
> For the CONNECT_E_NOCONNECTION error, verify that there is a
> connection point entry for the globally unique identifier (GUID) of
> the event interface in the connection point map, as in the following
> example:
> Sample Code
> BEGIN_CONNECTION_POINT_MAP(CMySource)
>   CONNECTION_POINT_ENTRY(DIID__MySourceEvents)
> END_CONNECTION_POINT_MAP()
> ++++++++++++++++++++++++++++++++++++++++++++
> The function works properly if it is called from an application.
> Fails only when called from another DCOM!
>
> "Alexander Nickolov" <agnickolov@mvps.org> wrote in message 
> news:<eBA7riumEHA.3756@TK2MSFTNGP09.phx.gbl>...
>> Debug your code to see why you return that error. It's
>> your code that returns it after all... Note this is an
>> interface-specific error code, your assumption about
>> its meaning is likely wrong.
>>
>> -- 
>> =====================================
>> Alexander Nickolov
>> Microsoft MVP [VC], MCSD
>> email: agnickolov@mvps.org
>> MVP VC FAQ: http://www.mvps.org/vcfaq
>> =====================================
>> "Sanjay Dattatri" <sdattatri@vsnl.com> wrote in message
>> news:2c3fbb74.0409141940.379a8798@posting.google.com...
>> > Hi,
>> > I have the following problem.  I have some DCOM classes which work
>> > fine when they are called from a VC++ MDI client or a ASP, but dont
>> > work when called from other DCOM classes.
>> >
>> > For example I have a compression class that works perfectly when
>> > called from ASP, VC++ client, but not from another DCOM [the code for
>> > both are given below].  In the latter case it returns with 80040200
>> > [NOCONNECTION]].
>> > The funny thing is that if I create a CString object in the caller
>> > function AFTER the DCOM call is made, then the DCOM to DCOM call
>> > works!!!
>> > I am sure I have missed something fundamental here.  Can someone throw
>> > any light, please?
>> >
>> > Thanks in advance.
>> > Sanjay
>> >
>> > -----------------------------------------------------------------------------------------------
>> > // Compress.h : Declaration of the CCompress
>> >
>> > #ifndef __COMPRESS_H_
>> > #define __COMPRESS_H_
>> >
>> > #include "resource.h"       // main symbols
>> >
>> > /////////////////////////////////////////////////////////////////////////////
>> > // CCompress
>> > class ATL_NO_VTABLE CCompress :
>> > public CComObjectRootEx<CComSingleThreadModel>,
>> > public CComCoClass<CCompress, &CLSID_Compress>,
>> > public IDispatchImpl<ICompress, &IID_ICompress, &LIBID_SPSCOMUTILLib>
>> > {
>> > public:
>> > CCompress()
>> > {
>> > }
>> >
>> > DECLARE_REGISTRY_RESOURCEID(IDR_COMPRESS)
>> >
>> > DECLARE_PROTECT_FINAL_CONSTRUCT()
>> >
>> > BEGIN_COM_MAP(CCompress)
>> > COM_INTERFACE_ENTRY(ICompress)
>> > COM_INTERFACE_ENTRY(IDispatch)
>> > END_COM_MAP()
>> >
>> >
>> > // ICompress
>> > public:
>> > STDMETHOD(ReduceXml)(/*[in]*/BSTR bstrInput, /*[in, out]*/VARIANT*
>> > varOutput, /*[in, out]*/ VARIANT* varErrData, /*[
>> >
>> > out, retval]*/short* bSuccess);
>> > STDMETHOD(ODecompress)(/*[in]*/VARIANT *vtInData, /*[in,
>> > out]*/VARIANT* varRetData, /*[out, retval]*/short* bSuccess
>> >
>> > );
>> > STDMETHOD(OCompress)(/*[in]*/BSTR bstrInput, /*[in, out]*/VARIANT*
>> > varRetData, /*[out, retval]*/short* bSuccess);
>> > };
>> >
>> > #endif //__COMPRESS_H_
>> > -------------------------------------------------------------------------------------------------------
>> >
>> > Calling function [This is a member in another DCOM]
>> > +++++++++++++++++++++++++++++++++++++++++++++++++++
>> > STDMETHODIMP CDCOMSchStoreXML::UpdateXML(BSTR bstrSessionId, BSTR
>> > schObjId,
>> >
>> >
>> > BSTR baseLineId, BSTR strXML,
>> >
>> >
>> > BSTR timestmp)
>> > {
>> > HRESULT hResult = S_FALSE;
>> > _ConnectionPtr pConn = NULL;
>> > _RecordsetPtr pRecordSet = NULL;
>> >
>> > FieldsPtr pFields = NULL;
>> > FieldPtr pField = NULL;
>> > _bstr_t strQueryStr(L"");
>> >
>> > _bstr_t bstrSchObjId(schObjId);
>> > _bstr_t bstrBaseLineId(baseLineId);
>> > _bstr_t bstrXML(strXML);
>> > _bstr_t bstrTimeStmp(timestmp);
>> >
>> > // Compress the Xml using SpsComUtil's interface to ZLib
>> > SPSCOMUTIL::ICompress* pCompress = NULL;
>> > CLSID clsId;
>> > VARIANT varCompressedXml;
>> > short bSuccess = 0;
>> >
>> > // 1. Get the Class Id for the Interface to query
>> > CString strClsId(_T("SpsComUtil.Compress"));
>> > BSTR bstrClsId = NULL;
>> >
>> > try
>> > {
>> > bstrClsId = strClsId.AllocSysString();
>> > ComUtils::Test_HResult(CLSIDFromProgID((LPCOLESTR)bstrClsId,
>> > &clsId));
>> >
>> > // 2. Create an instance of the interface
>> > hResult = m_spObjectContext->CreateInstance(clsId,
>> >
>> >
>> > (__uuidof(SPSCOMUTIL::ICompress)),
>> >
>> >
>> > (void**)&pCompress);
>> > ComUtils::Test_HResult(hResult);
>> >
>> >
>> > // 3. Call the method
>> > ComUtils::Test_HResult(hResult = pCompress->OCompress(strXML,
>> > &varCompressedXml, &bSuccess));
>> > // varCompressedXml contains Safe Array so can be used directly to
>> > AppendChunk
>> >
>> > strQueryStr = "SELECT xmlData, xmlTimeStmp FROM scheduleObj WHERE "
>> >                  "schObjId = '" + bstrSchObjId + "' AND "
>> >                  "baselineId = '" + bstrBaseLineId + "' " ;
>> >
>> > _bstr_t bstrTempConnString =
>> > DBUtils::GetDecryptedConnectionString(bstrSessionId);
>> >
>> > if (S_OK == (hResult = pConn.CreateInstance(__uuidof(Connection))) )
>> > {
>> > if (S_OK == (hResult = pConn->Open(bstrTempConnString, "", "", -1))
>> > )
>> > {
>> > if (S_OK == (hResult =
>> > pRecordSet.CreateInstance(__uuidof(Recordset))) )
>> > {
>> > if (S_OK == (hResult = pRecordSet->Open(_variant_t(strQueryStr),
>> > _variant_t((IDispatch *)
>> >
>> > pConn,true), adOpenKeyset,
>> > adLockOptimistic, adCmdText))
>> >
>> > )
>> > {
>> >
>> > if(pRecordSet->GetRecordCount() != 1) // No record found!!
>> > hResult = S_FALSE;
>> > else
>> > {
>> > pFields = pRecordSet->Fields;
>> > pField = pFields->Item[SCHOBJTAB_XMLDATA];
>> > //hResult = pField->AppendChunk(_variant_t(varCompressedXml));
>> > pField->Value = varCompressedXml;
>> > if (S_OK == hResult)
>> > {
>> > pField = pFields->Item[SCHOBJTAB_XMLTIMESTAMP];
>> > pField->Value = _variant_t(bstrTimeStmp);
>> >
>> > hResult = pRecordSet->Update();
>> > }
>> > }
>> >
>> > pRecordSet->Close();
>> > }
>> >
>> > pConn->Close();
>> > }
>> > }
>> > }
>> > }
>> > catch(_com_error &e)
>> > {
>> > WORD wCode = e.WCode();
>> > hResult = _com_error::WCodeToHRESULT(wCode);
>> > }
>> > catch(...)
>> > {
>> > hResult = E_UNEXPECTED;
>> > }
>> > CString str; str.Format("hResult is %x", hResult); // REMOVE these two
>> > lines and the call to compress
>> >    // will FAIL!!!
>> > LogUtils::WriteTrace("SPSCOMRET", str);
>> > ::SysFreeString(bstrClsId);
>> >
>> > #ifndef NO_MTS
>> > if (S_OK == hResult)
>> > m_spObjectContext->SetComplete();
>> > else
>> > m_spObjectContext->SetAbort();
>> > #endif
>> >
>> > return hResult;
>> > }

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