Problems with Internet classes in MSVC 4.2

Ram Kishore -- Ram_Kishore.IDEA@idea.com
Wednesday, October 16, 1996

Environment: Windows NT 4.0, MSVC 4.2 ( with patch 4.2a and 4.2b )

Hi all,
 I'm using the Internet classes that are provided with VC++ 4.2.

code snippet follows:
==============================================================
 CInternetSession* pInternetSess = NULL;
 CHttpConnection* pHttpConn = NULL;
 CHttpFile* pHttpFile = NULL;
 pInternetSess = (CInternetSession*) new CInternetSession;
 pHttpConn =  pInternetSess->GetHttpConnection(strServerName, nPort);

  while (1)
{
 // change the parameters - lszInput, lszHeader
 // also delete pHttpFile object if it already exists

 pHttpFile = pHttpConn->OpenRequest(CHttpConnection::HTTP_VERB_POST,
  strObject,(LPCTSTR)m_szURL, 1,NULL, NULL,dwHttpRequestFlags);
 Success = pHttpFile->SendRequest ( lszHeader,  lszHeader.GetLength(), 
                     lszInput.GetBuffer (0), lszInput.GetLength());
            
 pHttpFile->QueryInfoStatusCode(dwRetStatus);
 if (dwRetStatus != HTTP_STATUS_OK)
 {
  // failure , stop the program 
  break;
 }
 
}
==============================================================
Now this code works fine - for some time - 30 min to 1 hour.
After that the program hangs or ASSERTs in QueryInfoStatusCode(...)
Then I went inside this function and got the code out of it and put a check in 
my program
i.e put
 if (AfxGetInternetHandleType (pHttpFile->m_hFile) == AFX_INET_SERVICE_UNK)
 {
  // problemmmmmm.....
 }
code  before Query status info code.
Whenever we have the statue AFX_INET_SERVICE_UNK ( Unknown Service possibly 
?????? ),
it will ASSERT. But we don't know when and how it happens ?
Any light on this is highly Appreciated .
Also, any thing else that could be the problem with these classes ??
Thanks in Advance
Ram Kishore
rkishore@idea.com

---

Mike Blaszczak -- mikeblas@nwlink.com
Friday, October 18, 1996

At 17:46 10/16/96 EDT, Ram Kishore  wrote:
>Environment: Windows NT 4.0, MSVC 4.2 ( with patch 4.2a and 4.2b )

>Hi all,
> I'm using the Internet classes that are provided with VC++ 4.2.

>code snippet follows:
>==============================================================
> CInternetSession* pInternetSess = NULL;
> CHttpConnection* pHttpConn = NULL;
> CHttpFile* pHttpFile = NULL;
> pInternetSess = (CInternetSession*) new CInternetSession;
> pHttpConn =  pInternetSess->GetHttpConnection(strServerName, nPort);
>
>  while (1)
>{
> // change the parameters - lszInput, lszHeader
> // also delete pHttpFile object if it already exists
>
> pHttpFile = pHttpConn->OpenRequest(CHttpConnection::HTTP_VERB_POST,
>  strObject,(LPCTSTR)m_szURL, 1,NULL, NULL,dwHttpRequestFlags);
> Success = pHttpFile->SendRequest ( lszHeader,  lszHeader.GetLength(), 
>                     lszInput.GetBuffer (0), lszInput.GetLength());
>            
> pHttpFile->QueryInfoStatusCode(dwRetStatus);
> if (dwRetStatus != HTTP_STATUS_OK)
> {
>  // failure , stop the program 
>  break;
> }
>}

>==============================================================
>Now this code works fine - for some time - 30 min to 1 hour.
>After that the program hangs or ASSERTs in QueryInfoStatusCode(...)

Undoubtedly, this is because you never close any of the files that you open.
You need to code both:

        pHttpFile->Close();
        delete pHttpFile;

in each iteration of your loop. Note that you need to do that whether
dwRetStuats is HTTP_STATUS_OK or not.  Your program ends up getting
sick because you leak files and memory all over the place in a loop
that never ends.

.B ekiM
http://www.nwlink.com/~mikeblas/
Don't look at my hands: look at my _shoulders_!
These words are my own. I do not speak on behalf of Microsoft.

---

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