Lisa
Sun Jul 24 21:39:40 CDT 2005
I think I have to release all ->get_text(bStr) calls with
::SysFreeString(bStr) right?
Anything else?
"Lisa Pearlson" <no@spam.plz> wrote in message
news:eH14OwLkFHA.2904@tk2msftngp13.phx.gbl...
> So, the sample I gave you, that I found on the net is buggy because it
> doesn't release any of the interface?
>
> Do you see any memory leak in my code below?
>
> // simplified struct
> typedef struct NAME
> {
> std::wstring name;
> }
> vector<Names> g_vNames;
>
> BOOL InitNamesList()
> {
> IXMLDOMDocument *iXMLDoc = NULL;
> IXMLDOMParseError *pParsingErr = NULL;
> IXMLDOMElement *iXMLElm = NULL;
> IXMLDOMNodeList *iXMLChilds = NULL;
> IXMLDOMNode *iXMLItem = NULL;
> IXMLDOMNamedNodeMap *iXMLAttribs = NULL;
>
> BOOL bSuccess = FALSE;
>
> HRESULT hr = ::CoCreateInstance(CLSID_DOMDocument, NULL,
> CLSCTX_INPROC_SERVER | CLSCTX_LOCAL_SERVER,
> IID_IXMLDOMDocument, (LPVOID *)&iXMLDoc);
>
> if (iXMLDoc)
> {
> iXMLDoc->put_async(VARIANT_FALSE);
>
> // Pocket PC workaround: Remove document safety options
> IObjectSafety *pSafety = NULL;
> if (SUCCEEDED(iXMLDoc->QueryInterface(IID_IObjectSafety,
> (void**)&pSafety)))
> {
> DWORD dwSupported, dwEnabled;
> pSafety->GetInterfaceSafetyOptions(IID_IXMLDOMDocument, &dwSupported,
> &dwEnabled );
> pSafety->SetInterfaceSafetyOptions(IID_IXMLDOMDocument, dwSupported,
> 0 );
> pSafety->Release();
> }
>
> VARIANT_BOOL vSuccess = VARIANT_FALSE;
> /*
> hr = iXMLDoc->loadXML(
> L"<providers>"
> L" <provider name=\"Provider 1\" inserver=\"www1\"/>"
> L" <provider name=\"Provider 2\" inserver=\"www2\"/>"
> L"</providers>",
> &bSuccess);
> */
>
> TCHAR szAppPath[255];
> if (!::GetModuleFileName(NULL, szAppPath, ARRAYSIZE(szAppPath)))
> goto exitInit;
> tstring sPath(szAppPath);
> int npos = sPath.rfind(_T("\\"));
> if (npos >= 0)
> sPath = sPath.substr(0, npos);
> else
> sPath = _T("");
>
> sPath += _T("\\providers.xml");
>
> if ( IStream* pStream = CMyStream::Create( sPath.c_str() ) )
> {
> VARIANT_BOOL vSuccess = VARIANT_FALSE;
> VARIANT vSource;
>
> VariantInit( &vSource );
> vSource.punkVal = pStream;
> vSource.vt = VT_UNKNOWN;
>
> hr = iXMLDoc->load(vSource, &vSuccess);
>
> pStream->Release();
> }
> else
> goto exitInit;
>
>
> if (!SUCCEEDED(hr))
> goto exitInit;
>
> iXMLDoc->get_documentElement(&iXMLElm);
> iXMLElm->get_childNodes(&iXMLChilds);
> iXMLChilds->reset();
>
> while (S_OK == iXMLChilds->nextNode(&iXMLItem))
> {
> if (S_OK != iXMLItem->get_attributes(&iXMLAttribs))
> continue;
>
> NAME p;
> BSTR bStr;
> if (S_OK == iXMLAttribs->getNamedItem(_T("name"), &iXMLItem))
> {
> if (S_OK == iXMLItem->get_text(&bStr))
> p.name = bStr;
> }
> g_vNames.push_back(p);
> }
> }
>
> bSuccess = TRUE;
>
> exitInit:
> if (pParsingErr)
> pParsingErr->Release();
>
> if (iXMLElm)
> iXMLElm->Release();
>
> if (iXMLAttribs)
> iXMLAttribs->Release();
>
> if (iXMLItem)
> iXMLItem->Release();
>
> if (iXMLChilds)
> iXMLChilds->Release();
>
> if (iXMLDoc)
> iXMLDoc->Release();
>
> return bSuccess;
> }
>
> "Mateusz £oskot" <see.my@signature.net> wrote in message
> news:95a46$42e3a1c9$3eb356b9$11875@news.chello.pl...
>> Hi,
>>
>> Lisa Pearlson napisa³(a):
>>> How come in this example below I don't see any of that? Are they so
>>> called
>>> 'smart pointers' ? I don't think so.
>>
>> Do you mean all variables of type IXMLDOM... are smart pointers?
>> No, they aren't.
>>
>> ATL (I'd recommend you to learn ATL)
>> provides two smart pointers for COM: CComPtr and CComQIPtr.
>> All those smart pointers encapsulates addref/release calls
>> so programmer is not required to remember about calling addref and
>> release, so it helps to avoid memory leaks and to control object life
>> time.
>>
>> Cheers
>>
>> --
>> Mateusz £oskot
>> mateusz at loskot dot net
>
>