MSXML4 causing Leak

EDN Admin · Dec 10, 2010

MSXML4 is causing a leak. Its a MultiThreaded Application which causes a leak after X no. of requests.
Below is the Code where the request is parsed.

void DataSetRequest::loadXML(const char* dataSetRequestXML) 
{ 
_xmlSizeBytes = strlen(dataSetRequestXML) * sizeof(char); // store for stats logging 
 
if (_xmlSizeBytes == 0) 
{ 
throw EngineException(DSEE_EMPTY_DATASETREQUEST_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
"Expected an XML DataSetRequest. Instead got zero length input"); 
} 
 
IXMLDOMDocument2Ptr pRequestDoc; 
HRESULT _hr = pRequestDoc.CreateInstance("Msxml2.FreeThreadedDOMDocument.4.0"); 
if FAILED(_hr) 
{ 
throw EngineException(DSEE_COM_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
"Failed COM result handle creating Msxml2.FreeThreadedDOMDocument.4.0 instance"); 
} 
 
pRequestDoc->PutvalidateOnParse(false); 
 
BSTR tempBstr; 
 
try 
{ 
// parse the DataSetRequest 
tempBstr = stringToBstr(dataSetRequestXML); 
VARIANT_BOOL res = pRequestDoc->loadXML(tempBstr); 
 
if (res == FALSE) 
{ 
::SysFreeString(tempBstr); 
throw EngineException(DSEE_DATASETREQUEST_PARSE_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
"Error loading DataSetRequest XML", 
pRequestDoc->GetparseError()); 
} 
} 
catch (_com_error &e) 
{ 
::SysFreeString(tempBstr); 
 
throw EngineException(DSEE_DATASETREQUEST_PARSE_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
"COM Error loading DataSetRequest XML", 
e); 
} 
 
::SysFreeString(tempBstr); 
 
 
// add DataSet namespace to document so selectSingleNode() works with prefixes 
// NOTE: ds: prefix here must match select statement prefixes below 
string namespaces = "xmlns:ds=" + (string) DATASET_NAMESPACE + ""; 
pRequestDoc->setProperty("SelectionNamespaces", namespaces.c_str() ); 
 
// QueryRequest 
_pQueryRequestNode = pRequestDoc->selectSingleNode("//ds:QueryRequest"); 
if (_pQueryRequestNode == NULL) 
{ 
throw EngineException(DSEE_DATASETREQUEST_PARSE_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
"Could not extract QueryRequest element from DataSetRequest XML"); 
} 
 
char* tempStr; 
 
// requestId attribute 
IXMLDOMNodePtr requestIdNode = pRequestDoc->selectSingleNode("//@requestId"); 
if (requestIdNode != NULL) 
{ 
tempStr = bstrToString(requestIdNode->Gettext()); 
_requestId = std::string(tempStr); 
delete [] tempStr; 
 
if (_requestId.length == 0) 
{ 
_requestId = "EMPTY-STRING"; 
} 
} 
else 
{ 
_requestId = "MISSING"; 
} 
 
// languageId node 
IXMLDOMNodePtr langIdNode = pRequestDoc->selectSingleNode("//ds:LanguageID"); 
if (langIdNode != NULL) 
{ 
string languageId; 
tempStr = bstrToString(langIdNode->Gettext()); 
languageId = std::string(tempStr); 
delete [] tempStr; 
 
sscanf(languageId.c_str(),"%d",& _dartLanguageId); 
} 
 
// character encoding node 
IXMLDOMNodePtr charEncodingNode = pRequestDoc->selectSingleNode("//ds:CharacterEncoding"); 
if (charEncodingNode != NULL) 
{ 
tempStr = bstrToString(charEncodingNode->Gettext()); 
_characterEncoding = std::string(tempStr); 
delete [] tempStr; 
} 
 
// username node 
IXMLDOMNodePtr usernameNode = pRequestDoc->selectSingleNode("//ds:UserName"); 
if (usernameNode != NULL) 
{ 
tempStr = bstrToString(usernameNode->Gettext()); 
_username = std::string(tempStr); 
delete [] tempStr; 
} 
 
// rowStart node 
IXMLDOMNodePtr rowStartNode = pRequestDoc->selectSingleNode("//ds:RowStart"); 
if (rowStartNode != NULL) 
{ 
string rowStart; 
tempStr = bstrToString(rowStartNode->Gettext()); 
rowStart = std::string(tempStr); 
delete [] tempStr; 
 
sscanf(rowStart.c_str(),"%d",& _rowStart); 
 
if (_rowStart <=0) 
{ 
std:

stringstream msg; 
msg << "RowStart is one based and must be greater than zero: rowStart=" << _rowStart; 
 
throw EngineException(DSEE_DATASETREQUEST_VALIDATION_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
msg.str().c_str()); 
} 
} 
 
 
// rowCount node 
IXMLDOMNodePtr rowCountNode = pRequestDoc->selectSingleNode("//ds:RowCount"); 
if (rowCountNode != NULL) 
{ 
string rowCount; 
tempStr = bstrToString(rowCountNode->Gettext()); 
rowCount = std::string(tempStr); 
delete [] tempStr; 
 
sscanf(rowCount.c_str(),"%d",& _rowCount); 
 
if (_rowCount <=0) 
{ 
std:

stringstream msg; 
msg << "RowCount must be greater than zero: rowCount=" << _rowCount; 
 
throw EngineException(DSEE_DATASETREQUEST_VALIDATION_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
msg.str().c_str()); 
} 
} 
 
IXMLDOMNodePtr dataViewNode = pRequestDoc->selectSingleNode("//ds:QueryRequest/@dataView"); 
// bstrToString returns a pointer to a string and needs to be deleted explicitly. 
if (dataViewNode != NULL) 
{ 
tempStr = bstrToString(dataViewNode->Gettext()); 
_dataViewName = std::string(tempStr); 
delete [] tempStr; 
if (_dataViewName.length()==0) 
{ 
std:

stringstream msg; 
msg << "dataView attribute can not be empty"; 
 
throw EngineException(DSEE_DATASETREQUEST_VALIDATION_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
msg.str().c_str()); 
} 
_requestId += "/" + _username + "/" + _dataViewName; 
} 
 
// PivotInMemory node 
_bPivotInMemory = false; 
IXMLDOMNodePtr pivInMemNode = pRequestDoc->selectSingleNode("//ds

ivotInMemory"); 
if (pivInMemNode != NULL) 
{ 
string strPivInMem; 
tempStr = bstrToString(pivInMemNode->Gettext()); 
strPivInMem = std::string(tempStr); 
delete[] tempStr; 
 
if (!strPivInMem.compare("true") || !strPivInMem.compare("1")) 
_bPivotInMemory = true; 
else if (!strPivInMem.compare("false") || !strPivInMem.compare("0")) 
; // already false 
else 
{ 
std:

stringstream msg; 
msg << "PivotInMemory must be true,false,1, or 0. Current value: "
 
<< strPivInMem.c_str(); 
throw EngineException(DSEE_DATASETREQUEST_VALIDATION_ERROR, 
"DataSetRequest::loadXML()",__FILE__,__LINE__, 
msg.str().c_str()); 
} 
} 
} 
 
 
 

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MSXML4 causing Leak

EDN Admin

Well-known member