FIX: Hanging Occurs When Using CArrayRowset

RESOLUTION

Sample Code

   #include <oledberr.h>

   class CDBEndOfRowset
   {
   };

   template <class T, class TRowset = CRowset>
   class CArrRowset:

     public CVirtualBuffer<T>,
     public TRowset

   {

     public:
       CArrRowset(int nMax = 100000) : CVirtualBuffer<T>(nMax)
       {
         m_nRowsRead = 0;
       }


       int Except(LPEXCEPTION_POINTERS lpEP)
       {
          EXCEPTION_RECORD* pExcept = lpEP->ExceptionRecord;
          if (pExcept->ExceptionCode != EXCEPTION_ACCESS_VIOLATION)
             return EXCEPTION_CONTINUE_SEARCH;
          BYTE* pAddress = (LPBYTE) pExcept->ExceptionInformation[1];
          VirtualAlloc(pAddress, sizeof(T), MEM_COMMIT, PAGE_READWRITE);
          return EXCEPTION_CONTINUE_EXECUTION;
       }


       T& operator[](int nRow)
       {
         ATLASSERT(nRow >= 0);
         HRESULT hr;
         T* m_pCurrent = m_pBase + m_nRowsRead;
         T* pTEndofRowset = NULL;


         // Retrieve the row if you haven't retrieved it already.
         while ((ULONG)nRow >= m_nRowsRead)
         {
           m_pAccessor->SetBuffer((BYTE*)m_pCurrent);
           __try
          {
            // Get the row.
            hr = MoveNext();

            if (hr == DB_S_ENDOFROWSET)
               throw CDBEndOfRowset();

            if (hr != S_OK)
            {
               *((char*)0) = 0; // Force exception.
            }

          }
          __except(Except(GetExceptionInformation()))
          {
          }

          m_nRowsRead++;
          m_pCurrent++;
         }
         return *(m_pBase + nRow);
       }

       HRESULT Snapshot()
       {
         ATLASSERT(m_nRowsRead == 0);
         ATLASSERT(m_spRowset != NULL);
         HRESULT hr = MoveFirst();
         if (FAILED(hr))
           return hr;
         do
         {
            Write(*(T*)m_pAccessor->GetBuffer());
            m_nRowsRead++;
            hr = MoveNext();
         } while (SUCCEEDED(hr) &&  hr != DB_S_ENDOFROWSET);

         return (hr == DB_S_ENDOFROWSET) ? S_OK : hr;
       }


       // Implementation.
       ULONG   m_nRowsRead;
   };