Memory leak while parsing xml document using MSXML

Question

0.00/5 (No votes)

See more:

Hi,

I am facing a memory leak issue while parsing a XML document using MSXML.
Memory in task manager is increasing continuously and finally the application crashes.

Please find the below code snippet for same.

C++

void ValidateName(MSXML::IXMLDOMNodePtr pNode,CString sName,CString sController, bool& bRecurse, bool bControllerMatchFound)
{
	
	USES_CONVERSION;

	if (NULL == pNode)
		return  ;

	try
	{
		pNode->AddRef();
		// Recurse Children
		if (bRecurse)
		{
			
			CString strText;
			int nImageToAdd;
			int nSelectedImageToAdd;
			strText = NodeToTextImage(pNode, nImageToAdd, nSelectedImageToAdd);
			pNode->AddRef();

			m_pCurNode = pNode;
			MSXML::IXMLDOMNodePtr pParentNode	= m_pCurNode->GetparentNode();
			MSXML::IXMLDOMNamedNodeMapPtr pAttrList = pParentNode->Getattributes();
			if (NULL != pAttrList)				
			{
				
				MSXML::IXMLDOMAttributePtr pAttr;
				while (pAttr = pAttrList->nextNode())
				{
					CString strNodeName = W2T(pAttr->GetnodeName());
					CString strNodeAttribute;
					if ((strNodeName.CompareNoCase(_T("tag")) == 0) || (strNodeName.CompareNoCase(_T("id")) == 0) )
					{
						strNodeAttribute = W2T(_bstr_t(pAttr->GetnodeValue()));
						m_Info.SetParent(strNodeAttribute);
						break;
					}
				

				}
			}
			bRecurse = false;
			break;				
			MSXML::IXMLDOMNodeListPtr pNodeList = pNode->GetchildNodes();
			if (pNodeList != NULL)
			{
				MSXML::IXMLDOMNodePtr pChild;
				while(pChild = pNodeList->nextNode())
				{
					ValidateName(pChild,sName,sController, bRecurse,bControllerMatchFound);
				}
			}
		}
	}
	catch(_com_error e)
	{
		TRACE(_T("Caught Exception: FillXMLTree"));
		//ReportError(e, _T("tree scan"));
	}
	catch(...)
	{
		TRACE(_T("Caught Exception: FillXMLTree"));
		AfxMessageBox(_T("Error filling tree!"));
	}
	
}

The XML document contains many nodes in it. I am searching for a particular node element under it. But till completing execution of this function memory usage increases for each search.
I am using msxml.dll.

Is there anything wrong in this code or is there any mechanism by which I can free some memory during parsing.

Help of any kind will be highly appreciated.

Thank you.

Posted 17-Oct-13 20:59pm

cooltabrej

Updated 17-Oct-13 21:40pm

André Kraak

v3

Add a Solution

Comments

nv3 18-Oct-13 11:57am

As far as I understand your code, you only recurse to level 1, as you set bRecurse to false when processing the list of children. So it should be relatively easy to step through the code with a debugger.

You seem to have left code parts out; otherwise I can't see what the USES_CONVERSION should be good for that you do at the beginning.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

mbue · Accepted Answer · 2013-10-21T11:49:00

For the first the IXMLDOMNodePtr and IXMLDOMNamedNodeMapPtr etc. are smart pointers. they must not been AddRef'ed and not Release'd. If you call the AddRef you MUST call a Release to the same interface pointer! In your code are two AddRef calls and no Release. Thats the reason the parameter pNode is never Released.

On the position:

m_pCurNode = pNode;

I don't know what type

m_pCurNode

is but I assume its a smart pointer too. so you have only to remove the two

pNode->AddRef();

expressions from your code.

regards.