频振式杀虫灯:CSerialport串口类

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Module : serialport.h
Purpose: Declaration for an MFC wrapper class for serial ports
Created: PJN / 31-05-1999

Copyright (c) 1999 - 2002 by PJ Naughter. 
All rights reserved.

*/

 

///////////////////// Macros / Structs etc //////////////////////////

#ifndef __SERIALPORT_H__
#define __SERIALPORT_H__

 

 

/////////////////////////// Classes ///////////////////////////////////////////


////// Serial port exception class ////////////////////////////////////////////

void AfxThrowSerialException(DWORD dwError = 0);

typedef void (* pOnReceiveData)(void*,DWORD);

class CSerialException : public CException
{
public:
//Constructors / Destructors
 CSerialException(DWORD dwError);
 ~CSerialException();

//Methods
#ifdef _DEBUG
 virtual void Dump(CDumpContext& dc) const;
#endif
 virtual BOOL GetErrorMessage(LPTSTR lpstrError, UINT nMaxError, PUINT pnHelpContext = NULL);
 CString GetErrorMessage();

//Data members
 DWORD m_dwError;

protected:
 DECLARE_DYNAMIC(CSerialException)
};

 

//// The actual serial port class /////////////////////////////////////////////

class CSerialPort : public CObject
{
public:
//Enums
  enum FlowControl
  {
    NoFlowControl,
    CtsRtsFlowControl,
    CtsDtrFlowControl,
    DsrRtsFlowControl,
    DsrDtrFlowControl,
    XonXoffFlowControl
  };

  enum Parity
  {   
    EvenParity,
    MarkParity,
    NoParity,
    OddParity,
    SpaceParity
  };

  enum StopBits
  {
    OneStopBit,
    OnePointFiveStopBits,
    TwoStopBits
  };

//Constructors / Destructors
  CSerialPort();
  virtual ~CSerialPort();

//General Methods
  void Open(int nPort, DWORD dwBaud = 9600, Parity parity = NoParity, BYTE DataBits = 8,
            StopBits stopbits = OneStopBit, FlowControl fc = NoFlowControl, BOOL bOverlapped = FALSE);
  void Close();
  void Attach(HANDLE hComm, BOOL bOverlapped = FALSE);
  HANDLE Detach();
  operator HANDLE() const { return m_hComm; };
  BOOL IsOpen() const { return m_hComm != INVALID_HANDLE_VALUE; };
#ifdef _DEBUG
  void Dump(CDumpContext& dc) const;
#endif

//Reading / Writing Methods
  DWORD Read(void* lpBuf, DWORD dwCount);
  BOOL  Read(void* lpBuf, DWORD dwCount, OVERLAPPED& overlapped, DWORD* pBytesRead=NULL);
  void  ReadEx(void* lpBuf, DWORD dwCount);
  DWORD Write(const void* lpBuf, DWORD dwCount);
  BOOL  Write(const void* lpBuf, DWORD dwCount, OVERLAPPED& overlapped, DWORD* pBytesWritten=NULL);
  void  WriteEx(const void* lpBuf, DWORD dwCount);
  void  TransmitChar(char cChar);
  bool  GetOverlappedResult(OVERLAPPED& overlapped, DWORD& dwBytesTransferred, BOOL bWait);
  void  CancelIo();
  DWORD BytesWaiting();
  BOOL  DataWaiting(DWORD dwTimeout);
//Configuration Methods
  void GetConfig(COMMCONFIG& config);
  static void GetDefaultConfig(int nPort, COMMCONFIG& config);
  void SetConfig(COMMCONFIG& Config);
  static void SetDefaultConfig(int nPort, COMMCONFIG& config);

//Misc RS232 Methods
  void ClearBreak();
  void SetBreak();
  void ClearError(DWORD& dwErrors);
  void GetStatus(COMSTAT& stat);
  void GetState(DCB& dcb);
  void SetState(DCB& dcb);
  void Escape(DWORD dwFunc);
  void ClearDTR();
  void ClearRTS();
  void SetDTR();
  void SetRTS();
  void SetXOFF();
  void SetXON();
  void GetProperties(COMMPROP& properties);
  void GetModemStatus(DWORD& dwModemStatus);

//Timeouts
  void SetTimeouts(COMMTIMEOUTS& timeouts);
  void GetTimeouts(COMMTIMEOUTS& timeouts);
  void Set0Timeout();
  void Set0WriteTimeout();
  void Set0ReadTimeout();

//Event Methods
  void SetMask(DWORD dwMask);
  void GetMask(DWORD& dwMask);
  bool WaitEvent(DWORD& dwMask);
  BOOL WaitEvent(DWORD& dwMask, OVERLAPPED& overlapped);
 
//Queue Methods
  void Flush();
  void Purge(DWORD dwFlags);
  void TerminateOutstandingWrites();
  void TerminateOutstandingReads();
  void ClearWriteBuffer();
  void ClearReadBuffer();
  void Setup(DWORD dwInQueue, DWORD dwOutQueue);

//Overridables
  virtual void OnCompletion(DWORD dwErrorCode, DWORD dwCount, LPOVERLAPPED lpOverlapped);
//
  int GetComPortNum() { return m_CurPortNum; }
protected:
  HANDLE m_hComm;       //Handle to the comms port
  BOOL   m_bOverlapped; //Is the port open in overlapped IO
  HANDLE m_hEvent;      //A event handle we need for internal synchronisation

  int m_CurPortNum;    //当前串口号
  static void WINAPI _OnCompletion(DWORD dwErrorCode, DWORD dwCount, LPOVERLAPPED lpOverlapped);

 DECLARE_DYNAMIC(CSerialPort)
public:
 pOnReceiveData OnReceiveData;
};


#endif //__SERIALPORT_H__

 

/*
Module : serialport.CPP
Purpose: Implementation for an MFC wrapper class for serial ports
Created: PJN / 31-05-1999
History: PJN / 03-06-1999 1. Fixed problem with code using CancelIo which does not exist on 95.
                          2. Fixed leaks which can occur in sample app when an exception is thrown
         PJN / 16-06-1999 1. Fixed a bug whereby CString::ReleaseBuffer was not being called in
                             CSerialException::GetErrorMessage
         PJN / 29-09-1999 1. Fixed a simple copy and paste bug in CSerialPort::SetDTR
         PJN / 08-05-2000 1. Fixed an unreferrenced variable in CSerialPort::GetOverlappedResult in VC 6
         PJN / 10-12-2000 1. Made class destructor virtual
         PJN / 15-01-2001 1. Attach method now also allows you to specify whether the serial port
                          is being attached to in overlapped mode
                          2. Removed some ASSERT's which were unnecessary in some of the functions
                          3. Updated the Read method which uses OVERLAPPED IO to also return the bytes
                          read. This allows calls to WriteFile with a 0'ized overlapped structure (This
                          is required when dealing with TAPI and serial communications)
                          4. Now includes copyright message in the source code and documentation.
         PJN / 24-03-2001 1. Added a BytesWaiting method
         PJN / 04-04-2001 1. Provided an overriden version of BytesWaiting which specifies a timeout
         PJN / 23-04-2001 1. Fixed a memory leak in DataWaiting method
         PJN / 01-05-2002 1. Fixed a problem in Open method which was failing to initialize the DCB
                          structure incorrectly, when calling GetState. Thanks to Ben Newson for this fix.
         PJN / 29-05-2002 1. Fixed an problem where the GetProcAddress for CancelIO was using the
                          wrong calling convention
         PJN / 07-08-2002 1. Changed the declaration of CSerialPort::WaitEvent to be consistent with the
                          rest of the methods in CSerialPort which can operate in "OVERLAPPED" mode. A note
                          about the usage of this: If the method succeeds then the overlapped operation
                          has completed synchronously and there is no need to do a WaitForSingle/Multiple]Object.
                          If any other unexpected error occurs then a CSerialException will be thrown. See
                          the implementation of the CSerialPort::DataWaiting which has been rewritten to use
                          this new design pattern. Thanks to Serhiy Pavlov for spotting this inconsistency.
         PJN / 20-09-2002 1. Addition of an additional ASSERT in the internal _OnCompletion function.
                          2. Addition of an optional out parameter to the Write method which operates in
                          overlapped mode. Thanks to Kevin Pinkerton for this addition.

 

Copyright (c) 1996 - 2002 by PJ Naughter.  (Web: www.naughter.com, Email: pjna@naughter.com)

All rights reserved.

Copyright / Usage Details:

You are allowed to include the source code in any product (commercial, shareware, freeware or otherwise)
when your product is released in binary form. You are allowed to modify the source code in any way you want
except you cannot modify the copyright details at the top of each module. If you want to distribute source
code with your application, then you are only allowed to distribute versions released by the author. This is
to maintain a single distribution point for the source code.

*/

/////////////////////////////////  Includes  //////////////////////////////////

#include "stdafx.h"
#include "serialport.h"
#ifndef _WINERROR_
#include "winerror.h"
#endif

 

///////////////////////////////// defines /////////////////////////////////////

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

 


//////////////////////////////// Implementation ///////////////////////////////

//Class which handles CancelIo function which must be constructed at run time
//since it is not imeplemented on NT 3.51 or Windows 95. To avoid the loader
//bringing up a message such as "Failed to load due to missing export...", the
//function is constructed using GetProcAddress. The CSerialPort::CancelIo
//function then checks to see if the function pointer is NULL and if it is it
//throws an exception using the error code ERROR_CALL_NOT_IMPLEMENTED which
//is what 95 would have done if it had implemented a stub for it in the first
//place !!

class _SERIAL_PORT_DATA
{
public:
//Constructors /Destructors
  _SERIAL_PORT_DATA();
  ~_SERIAL_PORT_DATA();

  HINSTANCE m_hKernel32;
  typedef BOOL (WINAPI CANCELIO)(HANDLE);
  typedef CANCELIO* LPCANCELIO;
  LPCANCELIO m_lpfnCancelIo;
};

_SERIAL_PORT_DATA::_SERIAL_PORT_DATA()
{
  m_hKernel32 = LoadLibrary(_T("KERNEL32.DLL"));
  VERIFY(m_hKernel32 != NULL);
  m_lpfnCancelIo = (LPCANCELIO) GetProcAddress(m_hKernel32, "CancelIo");
}

_SERIAL_PORT_DATA::~_SERIAL_PORT_DATA()
{
  FreeLibrary(m_hKernel32);
  m_hKernel32 = NULL;
}


//The local variable which handle the function pointers

_SERIAL_PORT_DATA _SerialPortData;

 


////////// Exception handling code

void AfxThrowSerialException(DWORD dwError /* = 0 */)
{
 if (dwError == 0)
  dwError = ::GetLastError();

 CSerialException* pException = new CSerialException(dwError);

 TRACE(_T("Warning: throwing CSerialException for error %d\n"), dwError);
 THROW(pException);
}

BOOL CSerialException::GetErrorMessage(LPTSTR pstrError, UINT nMaxError, PUINT pnHelpContext)
{
 ASSERT(pstrError != NULL && AfxIsValidString(pstrError, nMaxError));

 if (pnHelpContext != NULL)
  *pnHelpContext = 0;

 LPTSTR lpBuffer;
 BOOL bRet = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
                         NULL,  m_dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_SYS_DEFAULT),
                         (LPTSTR) &lpBuffer, 0, NULL);

 if (bRet == FALSE)
  *pstrError = '\0';
 else
 {
  lstrcpyn(pstrError, lpBuffer, nMaxError);
  bRet = TRUE;

  LocalFree(lpBuffer);
 }

 return bRet;
}

CString CSerialException::GetErrorMessage()
{
  CString rVal;
  LPTSTR pstrError = rVal.GetBuffer(4096);
  GetErrorMessage(pstrError, 4096, NULL);
  rVal.ReleaseBuffer();
  return rVal;
}

CSerialException::CSerialException(DWORD dwError)
{
 m_dwError = dwError;
}

CSerialException::~CSerialException()
{
}

IMPLEMENT_DYNAMIC(CSerialException, CException)

#ifdef _DEBUG
void CSerialException::Dump(CDumpContext& dc) const
{
 CObject::Dump(dc);

 dc << "m_dwError = " << m_dwError;
}
#endif

 

 

////////// The actual serial port code

CSerialPort::CSerialPort()
{
  m_hComm = INVALID_HANDLE_VALUE;
  m_bOverlapped = FALSE;
  m_hEvent = NULL;
}

CSerialPort::~CSerialPort()
{
  Close();
}

IMPLEMENT_DYNAMIC(CSerialPort, CObject)

#ifdef _DEBUG
void CSerialPort::Dump(CDumpContext& dc) const
{
 CObject::Dump(dc);

 dc << _T("m_hComm = ") << m_hComm << _T("\n");
  dc << _T("m_bOverlapped = ") << m_bOverlapped;
}
#endif

void CSerialPort::Open(int nPort, DWORD dwBaud, Parity parity, BYTE DataBits, StopBits stopbits, FlowControl fc, BOOL bOverlapped)
{
  //Validate our parameters
  ASSERT(nPort>0 && nPort<=255);

  Close(); //In case we are already open

  //Call CreateFile to open up the comms port
  CString sPort;
  sPort.Format(_T("\\\\.\\COM%d"), nPort);
  DWORD dwCreateProperty;
  if(bOverlapped)
  {
     dwCreateProperty=FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED;
  }
  else
  {
  dwCreateProperty=FILE_ATTRIBUTE_NORMAL;
  }
  // bOverlapped ? FILE_FLAG_OVERLAPPED : 0
  m_hComm = CreateFile(sPort, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING,dwCreateProperty, NULL);
  if (m_hComm == INVALID_HANDLE_VALUE)
  {
    TRACE(_T("Failed to open up the comms port\n"));
    AfxThrowSerialException();
  }

  this->m_CurPortNum = nPort;
  //Create the event we need for later synchronisation use
 
  if(bOverlapped)
  {
 m_hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
 if (m_hEvent == NULL)
 {
  Close();
  TRACE(_T("Failed in call to CreateEvent in Open\n"));
  AfxThrowSerialException();
 }
  }
 
 
  m_bOverlapped = bOverlapped;
 
  //Get the current state prior to changing it
  DCB dcb;
  dcb.DCBlength = sizeof(DCB);
  GetState(dcb);

  //Setup the baud rate
  dcb.BaudRate = dwBaud;

  //Setup the Parity
  switch (parity)
  {
    case EvenParity:  dcb.Parity = EVENPARITY;  break;
    case MarkParity:  dcb.Parity = MARKPARITY;  break;
    case NoParity:    dcb.Parity = NOPARITY;    break;
    case OddParity:   dcb.Parity = ODDPARITY;   break;
    case SpaceParity: dcb.Parity = SPACEPARITY; break;
    default:          ASSERT(FALSE);            break;
  }

  //Setup the data bits
  dcb.ByteSize = DataBits;

  //Setup the stop bits
  switch (stopbits)
  {
    case OneStopBit:           dcb.StopBits = ONESTOPBIT;   break;
    case OnePointFiveStopBits: dcb.StopBits = ONE5STOPBITS; break;
    case TwoStopBits:          dcb.StopBits = TWOSTOPBITS;  break;
    default:                   ASSERT(FALSE);               break;
  }

  //Setup the flow control
  dcb.fDsrSensitivity = FALSE;
  switch (fc)
  {
    case NoFlowControl:
    {
      dcb.fOutxCtsFlow = FALSE;
      dcb.fOutxDsrFlow = FALSE;
      dcb.fOutX = FALSE;
      dcb.fInX = FALSE;
      break;
    }
    case CtsRtsFlowControl:
    {
      dcb.fOutxCtsFlow = TRUE;
      dcb.fOutxDsrFlow = FALSE;
      dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
      dcb.fOutX = FALSE;
      dcb.fInX = FALSE;
      break;
    }
    case CtsDtrFlowControl:
    {
      dcb.fOutxCtsFlow = TRUE;
      dcb.fOutxDsrFlow = FALSE;
      dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
      dcb.fOutX = FALSE;
      dcb.fInX = FALSE;
      break;
    }
    case DsrRtsFlowControl:
    {
      dcb.fOutxCtsFlow = FALSE;
      dcb.fOutxDsrFlow = TRUE;
      dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
      dcb.fOutX = FALSE;
      dcb.fInX = FALSE;
      break;
    }
    case DsrDtrFlowControl:
    {
      dcb.fOutxCtsFlow = FALSE;
      dcb.fOutxDsrFlow = TRUE;
      dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
      dcb.fOutX = FALSE;
      dcb.fInX = FALSE;
      break;
    }
    case XonXoffFlowControl:
    {
      dcb.fOutxCtsFlow = FALSE;
      dcb.fOutxDsrFlow = FALSE;
      dcb.fOutX = TRUE;
      dcb.fInX = TRUE;
      dcb.XonChar = 0x11;
      dcb.XoffChar = 0x13;
      dcb.XoffLim = 100;
      dcb.XonLim = 100;
      break;
    }
    default:
    {
      ASSERT(FALSE);
      break;
    }
  }
 
  //Now that we have all the settings in place, make the changes
  SetState(dcb);
}

void CSerialPort::Close()
{
  if (IsOpen())
  {
    //Close down the comms port
    BOOL bSuccess = CloseHandle(m_hComm);
    m_hComm = INVALID_HANDLE_VALUE;
    if (!bSuccess)
      TRACE(_T("Failed to close up the comms port, GetLastError:%d\n"), GetLastError());
    m_bOverlapped = FALSE;

    //Free up the event object we are using
    if(m_hEvent)
 {
    CloseHandle(m_hEvent);
       m_hEvent = NULL;
 }

  }
}

void CSerialPort::Attach(HANDLE hComm, BOOL bOverlapped)
{
  Close();
  m_hComm = hComm; 
  m_bOverlapped = bOverlapped;

  //Create the event we need for later synchronisation use
  m_hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
  if (m_hEvent == NULL)
  {
    Close();
    TRACE(_T("Failed in call to CreateEvent in Attach\n"));
    AfxThrowSerialException();
  }
}

HANDLE CSerialPort::Detach()
{
  HANDLE hrVal = m_hComm;
  m_hComm = INVALID_HANDLE_VALUE;
  CloseHandle(m_hEvent);
  m_hEvent = NULL;
  return hrVal;
}

DWORD CSerialPort::Read(void* lpBuf, DWORD dwCount)
{
  ASSERT(IsOpen());
  ASSERT(!m_bOverlapped);
 
  DWORD Errors;
  COMSTAT comstat;
  BOOL ok;
  ok = ::ClearCommError(this->m_hComm,&Errors,&comstat);
  if(!ok)
  {
     return 0;
  }
  if(comstat.cbInQue==0)
  {
     return 0;
  }

  DWORD dwBytesRead = 0;
  if (!ReadFile(m_hComm, lpBuf, comstat.cbInQue, &dwBytesRead, NULL))
  {
    TRACE(_T("Failed in call to ReadFile\n"));
    AfxThrowSerialException();
  }

  return dwBytesRead;
}

BOOL CSerialPort::Read(void* lpBuf, DWORD dwCount, OVERLAPPED& overlapped, DWORD* pBytesRead)
{
  ASSERT(IsOpen());
  ASSERT(m_bOverlapped);

  DWORD dwBytesRead = 0;
  DWORD Errors;
  COMSTAT comstat;
  /*
  BOOL ok;
  ok = ::ClearCommError(this->m_hComm,&Errors,&comstat);
  if(!ok)
  {
     return false;
  }
  if(comstat.cbInQue==0)
  {
     return false;
  }
  */
  BOOL bSuccess = ReadFile(m_hComm, lpBuf, dwCount, &dwBytesRead, &overlapped);
  if (!bSuccess)
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      TRACE(_T("Failed in call to ReadFile\n"));
      AfxThrowSerialException();
    }
  }
  else
  {
    if (pBytesRead)
      *pBytesRead = dwBytesRead;
  }
  return bSuccess;
}

DWORD CSerialPort::Write(const void* lpBuf, DWORD dwCount)
{
  ASSERT(IsOpen());
  ASSERT(!m_bOverlapped);

  DWORD dwBytesWritten = 0;
  if (!WriteFile(m_hComm, lpBuf, dwCount, &dwBytesWritten, NULL))
  {
    TRACE(_T("Failed in call to WriteFile\n"));
    AfxThrowSerialException();
  }

  return dwBytesWritten;
}

BOOL CSerialPort::Write(const void* lpBuf, DWORD dwCount, OVERLAPPED& overlapped, DWORD* pBytesWritten)
{
  ASSERT(IsOpen());
  ASSERT(m_bOverlapped);

  DWORD dwBytesWritten = 0;
  BOOL bSuccess = WriteFile(m_hComm, lpBuf, dwCount, &dwBytesWritten, &overlapped);
  if (!bSuccess)
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      TRACE(_T("Failed in call to WriteFile\n"));
      AfxThrowSerialException();
    }
  }
  else
  {
    if (pBytesWritten)
      *pBytesWritten = dwBytesWritten;
  }

  return bSuccess;
}

bool CSerialPort::GetOverlappedResult(OVERLAPPED& overlapped, DWORD& dwBytesTransferred, BOOL bWait)
{
  ASSERT(IsOpen());
  ASSERT(m_bOverlapped);
  BOOL bSuccess = ::GetOverlappedResult(m_hComm, &overlapped, &dwBytesTransferred, bWait);
  if (!bSuccess)
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      TRACE(_T("Failed in call to GetOverlappedResult\n"));
      AfxThrowSerialException();
    }
  }

  return bSuccess;
}

void CSerialPort::_OnCompletion(DWORD dwErrorCode, DWORD dwCount, LPOVERLAPPED lpOverlapped)
{
  //Validate our parameters
  ASSERT(lpOverlapped);

  //Convert back to the C++ world
  CSerialPort* pSerialPort = (CSerialPort*) lpOverlapped->hEvent;
  ASSERT(pSerialPort);
  ASSERT(pSerialPort->IsKindOf(RUNTIME_CLASS(CSerialPort)));

  //Call the C++ function
  pSerialPort->OnCompletion(dwErrorCode, dwCount, lpOverlapped);
}

void CSerialPort::OnCompletion(DWORD /*dwErrorCode*/, DWORD /*dwCount*/, LPOVERLAPPED lpOverlapped)
{
  //Just free up the memory which was previously allocated for the OVERLAPPED structure
  delete lpOverlapped;

  //Your derived classes can do something useful in OnCompletion, but don't forget to
  //call CSerialPort::OnCompletion to ensure the memory is freed up
}

void CSerialPort::CancelIo()
{
  ASSERT(IsOpen());

  if (_SerialPortData.m_lpfnCancelIo == NULL)
  {
    TRACE(_T("CancelIo function is not supported on this OS. You need to be running at least NT 4 or Win 98 to use this function\n"));
    AfxThrowSerialException(ERROR_CALL_NOT_IMPLEMENTED); 
  }

  if (!::_SerialPortData.m_lpfnCancelIo(m_hComm))
  {
    TRACE(_T("Failed in call to CancelIO\n"));
    AfxThrowSerialException();
  }
}

DWORD CSerialPort::BytesWaiting()
{
  ASSERT(IsOpen());

  //Check to see how many characters are unread
  COMSTAT stat;
  GetStatus(stat);
  return stat.cbInQue;
}

BOOL CSerialPort::DataWaiting(DWORD dwTimeout)
{
  ASSERT(IsOpen());
  ASSERT(m_hEvent);
  //Setup to wait for incoming data
  DWORD dwOldMask;
  GetMask(dwOldMask);
  SetMask(EV_RXCHAR);
  
  //Setup the overlapped structure
  OVERLAPPED o;
  o.hEvent = m_hEvent;

  //Assume the worst;
  BOOL bSuccess = FALSE;

  DWORD dwEvent;
  bSuccess = WaitEvent(dwEvent, o);
  if (!bSuccess)
  {
    if (WaitForSingleObject(o.hEvent, dwTimeout) == WAIT_OBJECT_0)
    {
      DWORD dwBytesTransferred;
      GetOverlappedResult(o, dwBytesTransferred, FALSE);
      bSuccess = TRUE;
    }
  }

  //Reset the event mask
  SetMask(dwOldMask);

  return bSuccess;
}

void CSerialPort::WriteEx(const void* lpBuf, DWORD dwCount)
{
  ASSERT(IsOpen());

  OVERLAPPED* pOverlapped = new OVERLAPPED;
  ZeroMemory(pOverlapped, sizeof(OVERLAPPED));
  pOverlapped->hEvent = (HANDLE) this;
  if (!WriteFileEx(m_hComm, lpBuf, dwCount, pOverlapped, _OnCompletion))
  {
    delete pOverlapped;
    TRACE(_T("Failed in call to WriteFileEx\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::ReadEx(void* lpBuf, DWORD dwCount)
{
  ASSERT(IsOpen());

  OVERLAPPED* pOverlapped = new OVERLAPPED;
  ZeroMemory(pOverlapped, sizeof(OVERLAPPED));
  pOverlapped->hEvent = (HANDLE) this;
  if (!ReadFileEx(m_hComm, lpBuf, dwCount, pOverlapped, _OnCompletion))
  {
    delete pOverlapped;
    TRACE(_T("Failed in call to ReadFileEx\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::TransmitChar(char cChar)
{
  ASSERT(IsOpen());

  if (!TransmitCommChar(m_hComm, cChar))
  {
    TRACE(_T("Failed in call to TransmitCommChar\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::GetConfig(COMMCONFIG& config)
{
  ASSERT(IsOpen());

  DWORD dwSize = sizeof(COMMCONFIG);
  if (!GetCommConfig(m_hComm, &config, &dwSize))
  {
    TRACE(_T("Failed in call to GetCommConfig\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::SetConfig(COMMCONFIG& config)
{
  ASSERT(IsOpen());

  DWORD dwSize = sizeof(COMMCONFIG);
  if (!SetCommConfig(m_hComm, &config, dwSize))
  {
    TRACE(_T("Failed in call to SetCommConfig\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::SetBreak()
{
  ASSERT(IsOpen());

  if (!SetCommBreak(m_hComm))
  {
    TRACE(_T("Failed in call to SetCommBreak\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::ClearBreak()
{
  ASSERT(IsOpen());

  if (!ClearCommBreak(m_hComm))
  {
    TRACE(_T("Failed in call to SetCommBreak\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::ClearError(DWORD& dwErrors)
{
  ASSERT(IsOpen());

  if (!ClearCommError(m_hComm, &dwErrors, NULL))
  {
    TRACE(_T("Failed in call to ClearCommError\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::GetDefaultConfig(int nPort, COMMCONFIG& config)
{
  //Validate our parameters
  ASSERT(nPort>0 && nPort<=255);

  //Create the device name as a string
  CString sPort;
  sPort.Format(_T("COM%d"), nPort);

  DWORD dwSize = sizeof(COMMCONFIG);
  if (!GetDefaultCommConfig(sPort, &config, &dwSize))
  {
    TRACE(_T("Failed in call to GetDefaultCommConfig\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::SetDefaultConfig(int nPort, COMMCONFIG& config)
{
  //Validate our parameters
  ASSERT(nPort>0 && nPort<=255);

  //Create the device name as a string
  CString sPort;
  sPort.Format(_T("COM%d"), nPort);

  DWORD dwSize = sizeof(COMMCONFIG);
  if (!SetDefaultCommConfig(sPort, &config, dwSize))
  {
    TRACE(_T("Failed in call to GetDefaultCommConfig\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::GetStatus(COMSTAT& stat)
{
  ASSERT(IsOpen());

  DWORD dwErrors;
  if (!ClearCommError(m_hComm, &dwErrors, &stat))
  {
    TRACE(_T("Failed in call to ClearCommError\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::GetState(DCB& dcb)
{
  ASSERT(IsOpen());

  if (!GetCommState(m_hComm, &dcb))
  {
    TRACE(_T("Failed in call to GetCommState\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::SetState(DCB& dcb)
{
  ASSERT(IsOpen());

  if (!SetCommState(m_hComm, &dcb))
  {
    TRACE(_T("Failed in call to SetCommState\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::Escape(DWORD dwFunc)
{
  ASSERT(IsOpen());

  if (!EscapeCommFunction(m_hComm, dwFunc))
  {
    TRACE(_T("Failed in call to EscapeCommFunction\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::ClearDTR()
{
  Escape(CLRDTR);
}

void CSerialPort::ClearRTS()
{
  Escape(CLRRTS);
}

void CSerialPort::SetDTR()
{
  Escape(SETDTR);
}

void CSerialPort::SetRTS()
{
  Escape(SETRTS);
}

void CSerialPort::SetXOFF()
{
  Escape(SETXOFF);
}

void CSerialPort::SetXON()
{
  Escape(SETXON);
}

void CSerialPort::GetProperties(COMMPROP& properties)
{
  ASSERT(IsOpen());

  if (!GetCommProperties(m_hComm, &properties))
  {
    TRACE(_T("Failed in call to GetCommProperties\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::GetModemStatus(DWORD& dwModemStatus)
{
  ASSERT(IsOpen());

  if (!GetCommModemStatus(m_hComm, &dwModemStatus))
  {
    TRACE(_T("Failed in call to GetCommModemStatus\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::SetMask(DWORD dwMask)
{
  ASSERT(IsOpen());

  if (!SetCommMask(m_hComm, dwMask))
  {
    TRACE(_T("Failed in call to SetCommMask\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::GetMask(DWORD& dwMask)
{
  ASSERT(IsOpen());

  if (!GetCommMask(m_hComm, &dwMask))
  {
    TRACE(_T("Failed in call to GetCommMask\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::Flush()
{
  ASSERT(IsOpen());

  if (!FlushFileBuffers(m_hComm))
  {
    TRACE(_T("Failed in call to FlushFileBuffers\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::Purge(DWORD dwFlags)
{
  ASSERT(IsOpen());

  if (!PurgeComm(m_hComm, dwFlags))
  {
    TRACE(_T("Failed in call to PurgeComm\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::TerminateOutstandingWrites()
{
  Purge(PURGE_TXABORT);
}

void CSerialPort::TerminateOutstandingReads()
{
  Purge(PURGE_RXABORT);
}

void CSerialPort::ClearWriteBuffer()
{
  Purge(PURGE_TXCLEAR);
}

void CSerialPort::ClearReadBuffer()
{
  Purge(PURGE_RXCLEAR);
}

void CSerialPort::Setup(DWORD dwInQueue, DWORD dwOutQueue)
{
  ASSERT(IsOpen());

  if (!SetupComm(m_hComm, dwInQueue, dwOutQueue))
  {
    TRACE(_T("Failed in call to SetupComm\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::SetTimeouts(COMMTIMEOUTS& timeouts)
{
  ASSERT(IsOpen());

  if (!SetCommTimeouts(m_hComm, &timeouts))
  {
    TRACE(_T("Failed in call to SetCommTimeouts\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::GetTimeouts(COMMTIMEOUTS& timeouts)
{
  ASSERT(IsOpen());

  if (!GetCommTimeouts(m_hComm, &timeouts))
  {
    TRACE(_T("Failed in call to GetCommTimeouts\n"));
    AfxThrowSerialException();
  }
}

void CSerialPort::Set0Timeout()
{
  COMMTIMEOUTS Timeouts;
  ZeroMemory(&Timeouts, sizeof(COMMTIMEOUTS));
  Timeouts.ReadIntervalTimeout = MAXDWORD;
  SetTimeouts(Timeouts);
}

void CSerialPort::Set0WriteTimeout()
{
  COMMTIMEOUTS Timeouts;
  GetTimeouts(Timeouts);
  Timeouts.WriteTotalTimeoutMultiplier = 0;
  Timeouts.WriteTotalTimeoutConstant = 0;
  SetTimeouts(Timeouts);
}

void CSerialPort::Set0ReadTimeout()
{
  COMMTIMEOUTS Timeouts;
  GetTimeouts(Timeouts);
  Timeouts.ReadIntervalTimeout = MAXDWORD;
  Timeouts.ReadTotalTimeoutMultiplier = 0;
  Timeouts.ReadTotalTimeoutConstant = 0;
  SetTimeouts(Timeouts);
}

bool CSerialPort::WaitEvent(DWORD& dwMask)
{
  ASSERT(IsOpen());
  ASSERT(!m_bOverlapped);

  if (!WaitCommEvent(m_hComm, &dwMask, NULL))
  {
    TRACE(_T("Failed in call to WaitCommEvent\n"));
    //AfxThrowSerialException();
 return false;
  }
  else
    return true;

}

BOOL CSerialPort::WaitEvent(DWORD& dwMask, OVERLAPPED& overlapped)
{
  ASSERT(IsOpen());
  ASSERT(m_bOverlapped);
  ASSERT(overlapped.hEvent);

  BOOL bSuccess = WaitCommEvent(m_hComm, &dwMask, &overlapped);
  if (!bSuccess)
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      TRACE(_T("Failed in call to WaitCommEvent\n"));
      AfxThrowSerialException();
    }
  }

  return bSuccess;
}