Hi all,

I am going to give the VC++ problems & solutions in this thread. If you have any problem while coding in VC++, you can place your questions here.
When I was working in VC++ for socket programming, I have faced lot of problems in sockets.
One of the big problem in socket programming is when I was using the socket in the multithreadding functionality, I have faced unhandled exception error.
I have faced the following problem, and after lot of searching through web I found the solution. I have mentioned the problem and solution here.

SYMPTOMS

When using MFC sockets in secondary threads in a statically linked MFC Visual C++ 6.0
application, an unhandled exception occurs.

CAUSE

The reason for the unhandled exception is that an object of type CMapPtrToPtr pointer,
pointed to by m_pmapSocketHandle, is never created.

RESOLUTION

The handle maps used by the sockets need to be created for each thread. The following
code shows a function to do this:

void SocketThreadInit()
{
#ifndef _AFXDLL

#define _AFX_SOCK_THREAD_STATE AFX_MODULE_THREAD_STATE

#define _afxSockThreadState AfxGetModuleThreadState()



_AFX_SOCK_THREAD_STATE* pState = _afxSockThreadState;

if (pState->m_pmapSocketHandle == NULL)

pState->m_pmapSocketHandle = new CMapPtrToPtr;

if (pState->m_pmapDeadSockets == NULL)

pState->m_pmapDeadSockets = new CMapPtrToPtr;

if (pState->m_plistSocketNotifications == NULL)

pState->m_plistSocketNotifications = new CPtrList;



#endif

}
This function should be called once in each secondary thread before the first socket
is created in the new thread.

thanks

__________________
Karpagarajan. R
Necessity is the mother of invention

Hi,

When I was doing the Composite control in ATL, I have faced the problem ATL - Composite control - Cannot include the class from the CTreeCtrl. I couldnt point out the error why it was occured and after long debugging, I have found out the solution.


Solution is to include the following sentence to the "Stdafx.h"

#ifndef _AFX_NO_AFXCMN_SUPPORT
#include <afxcmn.h> // MFC support for Windows Common Controls
#endif // _AFX_NO_AFXCMN_SUPPORT

thanks

__________________
Karpagarajan. R
Necessity is the mother of invention