C / C++ / MFC

LPUNKNOWN CAutoApp::m_lpUnk[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
CAutoApp::CAutoApp()
{
	EnableAutomation();
	for (int i=0; i < MAXNUMCONN && NULL != m_lpUnk[i]; i++);
	if (i < MAXNUMCONN)
		m_lpUnk[i] = GetInterface(&IID_IUnknown);
}

//see if any clients are still connected
int i=0;
while(i < MAXNUMCONN && NULL != CAutoApp::m_lpUnk[i])
{
    try
    {
        CAutoApp::m_lpUnk[i]->AddRef();
        CAutoApp::m_lpUnk[i++]->Release();
    }
    catch(...)
    {
        //connection no longer exists, remove from array
        for(int j=i; j<MAXNUMCONN-1 && NULL != CAutoApp::m_lpUnk[j]; j++)
            CAutoApp::m_lpUnk[j] = CAutoApp::m_lpUnk[j+1];
    }
}

//if connected to at least one client
if (NULL != CAutoApp::m_lpUnk[0])
{
    if (IsWindowVisible())
    {
        if (IDNO == AfxMessageBox("One or more remote connections is still active. Exit anyway?", MB_YESNO))
            //user decides not to close application
            return;
    }
    else
        //a client disconnected but do not close because other client(s) remain
        return;
}
            .....
        CMDIFrameWnd::OnClose();

void CMainFrame::OnCloseconnections() 
{
	if (IDNO == AfxMessageBox("This will close all connections. Are you sure?", MB_YESNO))
		return;

	//close all connections
	for (int i=0; NULL != CAutoApp::m_lpUnk[i]; i++)
	{
		try
		{
			while(CAutoApp::m_lpUnk[i]->Release());
		}
		catch(...)
		{
		}
		CAutoApp::m_lpUnk[i] = 0;
	}
}