terminate a thread problem

[lmadhavi]

Hi

I started a thread to check for a file change using the below code
Now on I have abutton on my UI. Onclick of the button I want to stop the above thread.

CWinThread* m_UpdateMonitorThread = AfxBeginThread(CheckFileUpdates,(LPVOID)this)
UINT CheckFileUpdates(LPVOID lp)
{
     //Get the document pointer
     CLogViewerAppView* pView = (CLogViewerAppView*)lp;
     CLogViewerAppDoc* pDoc = pView->GetDocument();

     CFileException err;
     CFileStatus st;
     CFile::GetStatus(pView->m_LogFilePath,st);
     LONG l1,l2;

     CFile file;
     if( !file.Open(pView->m_LogFilePath, CFile::modeRead|CFile::shareDenyNone, &err ) )
     {
          TCHAR szCause[255];
          err.GetErrorMessage(szCause, 255);
          AfxMessageBox(szCause);
          return 0;
     }
     l1 = (LONG)file.GetLength();
     file.Close();
     CFile file1;
     LONG size_1 = (LONG)st.m_size;
     int len = pView->m_LogFilePath.GetLength()-pView->m_LogFileName.GetLength()-1;
     CString dir = pView->m_LogFilePath.Left(len);
     HANDLE hDir = CreateFile( dir, // pointer to the file name
          FILE_LIST_DIRECTORY, // access (read/write) mode
          FILE_SHARE_READ|FILE_SHARE_WRITE, // share mode
          NULL, // security descriptor
          OPEN_EXISTING, // how to create
          FILE_FLAG_BACKUP_SEMANTICS, // file attributes
          NULL // file with attributes to copy
          );

     FILE_NOTIFY_INFORMATION Buffer[1024];
     DWORD BytesReturned;

     while( ReadDirectoryChangesW(
          hDir, // handle to directory
          &Buffer, // read results buffer
          sizeof(Buffer), // length of buffer
          TRUE, // monitoring option
          FILE_NOTIFY_CHANGE_SIZE, // filter conditions
          &BytesReturned, // bytes returned
          NULL, // overlapped buffer
          NULL// completion routine
          ))
     {
          if ( WaitForSingleObject(pView->m_StopEvent, INFINITE) == WAIT_OBJECT_0 )
                                    {
               OutputDebugString(_T("\n KIIGSRETG \n"));
                                                         return 0; //end the thraed

                                      }

          CString fileName(Buffer[0].FileName);
          fileName = fileName.Left(Buffer[0].FileNameLength / 2);

          if(fileName.CompareNoCase(pView->m_LogFileName) == 0)
          {
               //Do the work
          }
     }

     return 0;
}

But the m_StopEvent event is not caught beacuse the control is stuck at while( ReadDirectoryChangesW) I mean it not going inside the while loop unless ReadDirectoryChangesW returns true. Hence WaitForSingleObject is not checked at all..
Please help me to proceed further.

Thanks
Madhavi