Re: Reading Serial Port

On Feb 6, 6:49 pm, "David Ching" <d...@remove-this.dcsoft.com> wrote:


Ok, finally I think I solved it...
I added a
   delete pMySerial;
After WFSO in OnDestroy so I have no memory leaks now! Thank you.
About pReaderThread, I didn't set its m_bAutoDelete to FALSE, so I
suppose that I just need to WFSO for its m_hThread, isn't it?

This is my updated code with some comments:
First, creating the object:
    (MySerial*) pMySerial = (MySerial*)
AfxBeginThread( RUNTIME_CLASS( MySerial ), THREAD_PRIORITY_NORMAL, 0,
CREATE_SUSPENDED );

That's ok. Then I call:
   pMySerial->ResumeThread();
   pMySerial->openPort( port_number );

Here is my class (serial port related code ommited)
//Open_port(), here I crete the pReaderThread, a worker thread that
reads serial port
BOOL MySerial::openPort( int port )
{
    opened = TRUE;
    ShutdownEvent = CreateEvent( NULL, TRUE, FALSE, NULL );

    pReaderThread = AfxBeginThread( ReaderThread, this,
THREAD_PRIORITY_NORMAL, 0, CREATE_SUSPENDED );
    //pReaderThread->m_bAutoDelete = FALSE;
    //pReaderThread->ResumeThread();

    return TRUE;
}

//This is the famous ReaderThread, a worker thread that exits when
ShutDownEvent is signaled
UINT ReaderThread( LPVOID cT )
{
    MySerial* SerialHandler = (MySerial*)cT;

    HANDLE waiters[2];
    waiters[0] = SerialHandler->ShutdownEvent;
    waiters[1] = SerialHandler->ovReader.hEvent;

    while( reading )
    {
        unsigned char buffer[MAX_BUFFER_SIZE];
        BOOL ok = ::ReadFile( SerialHandler->hComm, buffer, MAX_BUFFER_SIZE
-1, &bytesRead, &SerialHandler->ovReader );
        if( !ok )
        {
            //Some code...
            DWORD result = ::WaitForMultipleObjects( 2, waiters, FALSE,
INFINITE );
            switch( result )
            {
                case WAIT_OBJECT_0: //Event shutdown
  reading = FALSE; //Here loop
quits
      continue;
                                //More code
            }
        }
        //More code to read
    }

    TRACE("\nREADER THREAD STOPPED.\n");
    return 0;
}

//And finally, the closePort()
void MySerial::closePort( WPARAM wparam, LPARAM lparam)
{
    TRACE("Hi!");
    if( opened )
    {
        SetEvent( ShutdownEvent );
        TRACE("closing pReaderThread.\n");
        WaitForSingleObject( pReaderThread->m_hThread, INFINITE );
//If I set in openPort() pReader->Thread->m_bAutodelete = FALSE...
// CloseHandle( pReaderThread->m_hThread ); //...Here I've
got an Exception error
// delete pReaderThread; //

        BOOL ok = PurgeComm( hComm, PURGE_RXABORT|PURGE_RXCLEAR );

        ::CloseHandle( WriteEvent );
        ::CloseHandle( ShutdownEvent );
        ::CloseHandle( ReadEvent );
        ::CloseHandle( hComm );

        PostQuitMessage(0);
        //PostThreadMessage(GetCurrentThreadId(), WM_QUIT, 0, 0);
        opened = FALSE;
        TRACE("THREAD STOPPED\n");
    }
    else
    {
        TRACE("Not opened.");
        PostQuitMessage(0);
        //PostThreadMessage(GetCurrentThreadId(), WM_QUIT, 0, 0);
    }
}

And in my OnDestroy I do this:
void CUart3DEMODlg::OnDestroy()
{
    CDialog::OnDestroy();
    TRACE("closing port.\n");
    if( serial_created ) //<<---Note this flag
    {
        TRACE("We have to kill pMySerial.\n");
        pMySerial->ResumeThread();
        pMySerial->PostThreadMessage( WM_MYSERIAL_CLOSE, 0, 0 );
        WaitForSingleObject( pMySerial->m_hThread, INFINITE );
        delete pMySerial;
        TRACE("Port closed.\n");
    }
}

I have to thank all people that helped me to find the solution,
But... one last thing (sorry):
The flag serial_created is true when I create pMySerial. When
serial_created is true at the moment of exit App, I must close it
properly.
But you'll agree with me that's shoddy... Is there a better way to
detect that pMySerial exists??

And again, thank you.