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.