Try to do this:

BSTR transResult = pInpXML->transformNode(pXSL);
...
...
...
if ( transResult )
    ::SysFreeString(transResult);

And free the transResult variable after using it.


"Ross Faneuf" <rfaneuf@i...> wrote in message
news:8fbf7730.0412011413.18911883@p......
> We have a Windows service which imports data into various databases.
> It runs continuously, polling a directory for XML files to transform
> and import. The import code uses MSXML 4.0 in C++ through the smart
> pointer interface to create two DOMDocument objects for each XML file
> and its transform. Boiled down, the code looks like this (extensive
> error handling etc. removed):
>
> void CImportSvc::doXMLTransformAux(...)
>    {
>    MSXML2::IXMLDOMDocument2Ptr   pXSL = NULL;
>    MSXML2::IXMLDOMDocument2Ptr   pInpXML = NULL;
>    _bstr_t                       transArg;
>    VARIANT_BOOL                  loadRes;
>
>    hr = pXSL.CreateInstance("Msxml2.DOMDocument.4.0");
>    pXSL->setProperty("ServerHTTPRequest", true);
>    pXSL->async = false;
>
>    try
>       {
>       loadRes = pXSL->load(<transform-file-name>);
>       }
>    catch( ... )
>       {
>       ...
>       }
>
>    hr = pInpXML.CreateInstance("Msxml2.DOMDocument.4.0");
>    pInpXML->setProperty("ServerHTTPRequest", true);
>    pInpXML->async = false;
>    try
>       {
>       loadRes = pInpXML->load(<xml-file-name>);
>       }
>    catch( ... )
>       {
>       ...
>       }
>
>    try
>       {
>       transArg = pInpXML->transformNode(pXSL);
>       }
>    catch(_com_error &e)
>       {
>       CString        errDescription;
>
>       errDescription = (LPCTSTR) e.Description();
>       // On failure, errDescription = "A dynamic link library (DLL)
> initialization routine failed."
>       }
>
>    // Free DOM objects
>    pXSL = NULL;
>    pInpXML = NULL;
>    }
>
> This code works just fine approximately 600 times. Eventually,
> pInpXML->transformNode fails and is caught with a _com_error, with the
> message shown above. Monitoring the process with Process Explorer
> shows no obvious memory leak - private bytes does not increase
> perceptibly.
>
> An outer routine surrounds this code fragment with
> ::CoInitialize()/::CoUnitialize() each time this code fragment is
> called. I have tried adding ::CoFreeAllLibraries() before
> ::CoUnitialize(), and I have confirmed using Process Explorer that
> msxml4.dll is unloaded; this has no effect. Presumably, MSXML garbage
> collection occurs when the library is unloaded.
>
> A symptom which appears in Process Explorer is handle consumption.
> Each time pInpXML->transformNode(pXSL); is called (seen by stepping in
> debugger), a WmiGuid handle is consumed by the process; eventually
> there are about 600, which are never freed. I don't know whether this
> handle is a symptom or cause of the problem, but it's the only
> resource I've been able to find which is being consumed.
>
> This behavior is reproducible running on a single machine with
> essentially no load on MSXML - this is not a busy Web Server
> situation. I don't believe the issues addressed in MS articles 304227
> or 297997 are relevant.
>
> Using MSXML 4.0 SP2.
>
> Anybody have a clue what's going on here?