CloseHandle(hFile);

    //EB_Printf(TEXT("cs=%x\n"),cs);
    threadResult=_beginthread( (void (*)(void *))TxFile,0x2000,(void *)0);
    if(threadResult!=-1)
    {
	//Create the download progress dialogbox.
	CreateDialog(_hInstance,MAKEINTRESOURCE(IDD_DIALOG1),hwnd,DownloadProgressProc); //modaless
	//ShowWindow(_hDlgDownloadProgress,SW_SHOW); 
    	//isn't needed because the dialog box already has WS_VISIBLE attribute.
    }
    else
    {
	EB_Printf(TEXT("[ERROR:Can't creat a thread. Memory is not sufficient]\n"));
    }
    //The dialog box will be closed at the end of TxFile().
    //free(txBuf) & CloseHandle(hWrite) will be done in TxFile()
}



void MenuOptions(HWND hwnd)
{
    int result;
    //Create the download progress dialogbox.
    result=DialogBox(_hInstance,MAKEINTRESOURCE(IDD_DIALOG2),_hwnd,OptionsProc); //modal
    if(result==1 && isConnected==1)
    {
	MenuConnect(hwnd); //reconfig the serial port.
    }
}





/*****************************
 *                           *
 * serial communication part *
 *                           *
 *****************************/

BOOL OpenComPort(int port)
//port=1,2,3,4
{
    TCHAR *textCom[]={TEXT("COM1"),TEXT("COM2"),TEXT("COM3"),TEXT("COM4")};
    DCB dcb;
    COMMTIMEOUTS commTimeOuts;
    
//====================================================
    osRead.Offset=0;
    osRead.OffsetHigh=0;
    osWrite.Offset=0;
    osWrite.OffsetHigh=0;

    osRead.hEvent = CreateEvent(NULL,TRUE/*bManualReset*/,FALSE,NULL);
     //manual reset event object should be used. 
     //So, system can make the event objecte nonsignalled.
     //osRead.hEvent & osWrite.hEvent may be used to check the completion of 
     // WriteFile() & ReadFile(). But, the DNW doesn't use this feature.
    if(osRead.hEvent==NULL)
    {
	EB_Printf(TEXT("[ERROR:CreateEvent for osRead.]\n"));
	return FALSE;
    }

    osWrite.hEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
    if(osWrite.hEvent==NULL)
    {
	EB_Printf(TEXT("[ERROR:CreateEvent for osWrite.]\n"));
	return FALSE;
    }

    
//====================================================
    idComDev=CreateFile(textCom[port-1],
			GENERIC_READ|GENERIC_WRITE,
			0, //exclusive access
			/*FILE_SHARE_READ|FILE_SHARE_WRITE,*/ 
			NULL,	
			OPEN_EXISTING,
		    #if IS_OVERLAPPED_IO
			FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED,
		    #else
			/*FILE_ATTRIBUTE_NORMAL,*/ 0,
		    #endif	
			NULL);

    if(idComDev==INVALID_HANDLE_VALUE)
    {
	//EB_Printf(TEXT("[ERROR:CreateFile for opening COM port.]\n") );
	return FALSE;
    }

    SetCommMask(idComDev,EV_RXCHAR);
    SetupComm(idComDev,4096,4096);
    PurgeComm(idComDev,PURGE_TXABORT|PURGE_RXABORT|PURGE_TXCLEAR|PURGE_RXCLEAR);
    
    commTimeOuts.ReadIntervalTimeout=0xffffffff;
    commTimeOuts.ReadTotalTimeoutMultiplier=0;
    commTimeOuts.ReadTotalTimeoutConstant=1000;
    commTimeOuts.WriteTotalTimeoutMultiplier=0;
    commTimeOuts.WriteTotalTimeoutConstant=1000;
    SetCommTimeouts(idComDev,&commTimeOuts);

//====================================================
    dcb.DCBlength=sizeof(DCB);
    GetCommState(idComDev,&dcb);

    dcb.fBinary=TRUE;
    dcb.fParity=FALSE;
    dcb.BaudRate=userBaudRate; //CBR_115200;
    dcb.ByteSize=8;
    dcb.Parity=0;
    dcb.StopBits=0;
    dcb.fDtrControl=DTR_CONTROL_DISABLE;
    dcb.fRtsControl=RTS_CONTROL_DISABLE;
    dcb.fOutxCtsFlow=0;
    dcb.fOutxDsrFlow=0;
    
    if(SetCommState(idComDev,&dcb)==TRUE)
    {	
	isConnected=TRUE;
	_beginthread( (void (*)(void *))DoRxTx,0x2000,(void *)0);
	return TRUE;
    }
    else
    {
	isConnected=FALSE;
	CloseHandle(idComDev);
	return FALSE;
    }
}




void CloseComPort(void)
{
    if(isConnected)
    {
	isConnected=FALSE;
	SetCommMask(idComDev,0);
	    //disable event notification and wait for thread to halt
	EscapeCommFunction(idComDev,CLRDTR);
	PurgeComm(idComDev,PURGE_TXABORT|PURGE_RXABORT|PURGE_TXCLEAR|PURGE_RXCLEAR);
	CloseHandle(idComDev);

        CloseHandle(osRead.hEvent);
	CloseHandle(osWrite.hEvent);
    }
    
    Sleep(100); 
    //wait until CloseComPort() effective.
    //If not, OpenComPort()::CreateFile(...) will fail.

}
	



void DoRxTx(void *args)
{
    OVERLAPPED os;
    DWORD dwEvtMask;
    int nLength;
    BOOL fStat;
    DWORD temp;

    memset(&os,0,sizeof(OVERLAPPED));
    os.hEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
    if(os.hEvent==NULL)
    {
	EB_Printf(TEXT("[ERROR:DoRxTx os.hEvent]\n"));
	_endthread();
    }

    if(!SetCommMask(idComDev,EV_RXCHAR|EV_TXEMPTY|EV_ERR))
    {
	EB_Printf(TEXT("[ERROR:SetCommMask()]\n"));
	CloseHandle(os.hEvent);
	_endthread();
    }

    while(isConnected)
    {
	dwEvtMask=0;
    #if IS_OVERLAPPED_IO
	fStat=WaitCommEvent(idComDev,&dwEvtMask,&os);   
	//Apr.28.2003: fStat should be checked for the cpu time saving. 
	if(!fStat)   //Apr.28.2003:GetOverlappedResult() is needed.  
	{
	    //By experiment. Only when there was no signalled event, the following was executed.
	    //EB_Printf(TEXT("\n[WaitCommEvent=false]\n") ); 
	    if(GetLastError()==ERROR_IO_PENDING)
	    {
		GetOverlappedResult(idComDev,&os,&temp,TRUE); 
	    }
	    else
	    {
		EB_Printf(TEXT("[RXTX_THREAD_ERR]") );
	    }
	}
    #else
	WaitCommEvent(idComDev,&dwEvtMask,NULL);  //wait until any event is occurred.
    #endif

	if( (dwEvtMask & EV_TXEMPTY) == EV_TXEMPTY )
	    txEmpty=TRUE;

	if((dwEvtMask & EV_RXCHAR) == EV_RXCHAR)
	{
	    do   //Apr.28.2003:The caveat on MSDN,"Serial Communications in Win32" recommends while();
	    {
		if( nLength=ReadCommBlock(rxBuf,MAX_BLOCK_SIZE) )
		{
		    if(nLength>=MAX_BLOCK_SIZE /*for debug*/)
		    {
			EB_Printf(TEXT("\n\n\n\n\n\n\n[ERROR:nLength>4096]\n"));
		    }
		    else
		    {
		    rxBuf[nLength]='\0';
		    //OutputDebugString(rxBuf);
		    EB_Printf(rxBuf);
		    }
		}
	    }while(nLength);  
	}

	// Clear OVERRUN condition.
	// If OVERRUN error is occurred,the tx/rx will be locked.
	if(dwEvtMask & EV_ERR)
	{
	    COMSTAT comStat;
	    DWORD dwErrorFlags;
	    ClearCommError(idComDev,&dwErrorFlags,&comStat);
	    //EB_Printf(TEXT("[DBG:EV_ERR=%x]\n"),dwErrorFlags);
	}
    }	
    CloseHandle(os.hEvent);
    _endthread();
}




int ReadCommBlock(char *buf,int maxLen)
{
    BOOL fReadStat;
    COMSTAT comStat;
    DWORD dwErrorFlags;
    DWORD dwLength;

    ClearCommError(idComDev,&dwErrorFlags,&comStat);
    dwLength=min((DWORD)maxLen,comStat.cbInQue);
    if(dwLength>0)
    {
    #if IS_OVERLAPPED_IO
	fReadStat=ReadFile(idComDev,buf,dwLength,&dwLength,&osRead);
	if(!fReadStat)   //Apr.28.2003:GetOverlappedResult() may be needed.
	{
	    //By experiment, fReadStat was always TRUE,of course, and the following was never executed.
	    //EB_Printf(TEXT("\n[RX_RD_WAIT]\n") ); 
	    if(GetLastError()==ERROR_IO_PENDING)
	    {
		GetOverlappedResult(idComDev,&osRead,&dwLength,TRUE); 
	    }
	    else
	    {
		EB_Printf(TEXT("[RXERR]") );
	    }
	}
    #else
	fReadStat=ReadFile(idComDev,buf,dwLength,&dwLength,NULL);
	if(!fReadStat)
	{
	    EB_Printf(TEXT("[RXERR]") );
	}

    #endif
    }
    return dwLength;
}





#define TX_SIZE 2048
//TX_SIZE must be less than 4096
void TxFile(void *args)
{
    void *txBlk;
    DWORD txBlkSize;
    DWORD fWriteStat;
    DWORD temp;
    InitDownloadProgress();
    while(txEmpty==FALSE);
    while(1)
    {
        if((txBufSize-iTxBuf) > TX_SIZE)
	    txBlkSize=TX_SIZE;
	else
	    txBlkSize=txBufSize-iTxBuf;
	
	txBlk=(void *)(txBuf+iTxBuf);

	txEmpty=FALSE;
    #if IS_OVERLAPPED_IO
	fWriteStat=WriteFile(idComDev,txBlk,txBlkSize,&temp,&osWrite);
	if(!fWriteStat)   //Apr.28.2003:GetOverlappedResult() may be needed.
	{
	    
	    if(GetLastError()==ERROR_IO_PENDING)
	    {
		GetOverlappedResult(idComDev,&osWrite,&temp,TRUE); 
		    //more efficient in order to save the cpu time
	    }
	    else
	    {
		EB_Printf(TEXT("[TXERR]") );
	    }
	}
	else
	{
	    //By experiment, never executed.
	    //EB_Printf(TEXT("\n[TX_NO_WR_WAIT]\n") ); 
	}
    #else
	WriteFile(idComDev,txBlk,txBlkSize,&temp,NULL);
	Sleep(TX_SIZE*1000/11520-10); //to save cpu time.
	while(txEmpty==FALSE);
    #endif
	iTxBuf+=TX_SIZE;
	
	DisplayDownloadProgress(iTxBuf*100/txBufSize);
	
	if(downloadCanceled==1)break;	//download is canceled by user.

	if(iTxBuf>=txBufSize)break;
    }
    free((void *)txBuf);

    CloseDownloadProgress();

    _endthread();
}




void WriteCommBlock(char c)
{
    void *txBlk;
    DWORD txBlkSize;
    static char _c;
    DWORD temp;

    _c=c;

    while(txEmpty==FALSE);
    txBlk=&_c;
    txBlkSize=1;

    //txEmpty=FALSE; why needed??? this line should be removed.
#if IS_OVERLAPPED_IO
    WriteFile(idComDev,txBlk,txBlkSize,&temp,&osWrite);
#else
    WriteFile(idComDev,txBlk,txBlkSize,&temp,NULL);
#endif
    while(txEmpty==FALSE);
}