这是一份优秀的类文件,好多的地方值得我们学习,具体在多线程,事件,自定义消息,类的封装方面等等。
Remon提供的串口类网址为: http://codeguru.earthweb.com/network/serialport.shtml,
由于已经运行十几年了,原文的问答部分列出来这么多年来的问题,经过网友们的总结,补充和修改原来代码后,整理出一份相对比较完美的代码。
此外还附带一份小项目的源代码,它超越了串口助手,给人一种耳目一新的感觉。亮点如下:
1. 它解决了串口关闭时出现死锁不响应问题,可以直接用到开发的项目上。
2. 并且是扩展了的串口助手,具有通信协议编辑和使用功能,
3. 软件升级检测,值得做软件升级例子使用。
4. 最重要的是源代码很不错,很值得大家去研究。
分享给需要的朋友们,有问题,可以在留言,以便做进一步修正。
VC串口修正类应用的小项目下载地址:http://download.csdn.net/detail/liquanhai/3763088
2014-01-11补充说明:
最新的CSerialPort类的下载地址在:https://github.com/liquanhai/CSerialPort
头文件CSerialPort.h如下:
- /*
- ** FILENAME CSerialPort.h
- **
- ** PURPOSE This class can read, write and watch one serial port.
- ** It sends messages to its owner when something happends on the port
- ** The class creates a thread for reading and writing so the main
- ** program is not blocked.
- **
- ** CREATION DATE 15-09-1997
- ** LAST MODIFICATION 12-11-1997
- **
- ** AUTHOR Remon Spekreijse
- **
- **
- ************************************************************************************
- ** author: mrlong date:2007-12-25
- **
- ** 改进
- ** 1) 增加ClosePort
- ** 2) 增加 writetoProt() 两个方法
- ** 3) 增加 SendData 与 RecvData 方法
- **************************************************************************************
- ***************************************************************************************
- ** author:liquanhai date:2011-11-04
- ** 改进
- ** 1)增加 ClosePort中交出控制权,防止死锁问题
- ** 2) 增加 ReceiveChar中防止线程死锁
- */
- #ifndef __SERIALPORT_H__
- #define __SERIALPORT_H__
- #define WM_COMM_BREAK_DETECTED WM_USER+1 // A break was detected on input.
- #define WM_COMM_CTS_DETECTED WM_USER+2 // The CTS (clear-to-send) signal changed state.
- #define WM_COMM_DSR_DETECTED WM_USER+3 // The DSR (data-set-ready) signal changed state.
- #define WM_COMM_ERR_DETECTED WM_USER+4 // A line-status error occurred. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY.
- #define WM_COMM_RING_DETECTED WM_USER+5 // A ring indicator was detected.
- #define WM_COMM_RLSD_DETECTED WM_USER+6 // The RLSD (receive-line-signal-detect) signal changed state.
- #define WM_COMM_RXCHAR WM_USER+7 // A character was received and placed in the input buffer.
- #define WM_COMM_RXFLAG_DETECTED WM_USER+8 // The event character was received and placed in the input buffer.
- #define WM_COMM_TXEMPTY_DETECTED WM_USER+9 // The last character in the output buffer was sent.
- class CSerialPort
- {
- public:
- // contruction and destruction
- CSerialPort();
- virtual ~CSerialPort();
- // port initialisation
- BOOL InitPort(CWnd* pPortOwner, UINT portnr = 1, UINT baud = 19200,
- char parity = 'N', UINT databits = 8, UINT stopsbits = 1,
- DWORD dwCommEvents = EV_RXCHAR | EV_CTS, UINT nBufferSize = 512,
- DWORD ReadIntervalTimeout = 1000,
- DWORD ReadTotalTimeoutMultiplier = 1000,
- DWORD ReadTotalTimeoutConstant = 1000,
- DWORD WriteTotalTimeoutMultiplier = 1000,
- DWORD WriteTotalTimeoutConstant = 1000);
- // start/stop comm watching
- BOOL StartMonitoring();
- BOOL RestartMonitoring();
- BOOL StopMonitoring();
- DWORD GetWriteBufferSize();
- DWORD GetCommEvents();
- DCB GetDCB();
- void WriteToPort(char* string);
- void WriteToPort(char* string,int n); // add by mrlong 2007-12-25
- void WriteToPort(LPCTSTR string); // add by mrlong 2007-12-25
- void WriteToPort(BYTE* Buffer, int n);// add by mrlong
- void ClosePort(); // add by mrlong 2007-12-2
- void SendData(LPCTSTR lpszData, const int nLength); //串口发送函数 by mrlong 2008-2-15
- BOOL RecvData(LPTSTR lpszData, const int nSize); //串口接收函数 by mrlong 2008-2-15
- protected:
- // protected memberfunctions
- void ProcessErrorMessage(char* ErrorText);
- static UINT CommThread(LPVOID pParam);
- static void ReceiveChar(CSerialPort* port, COMSTAT comstat);
- static void WriteChar(CSerialPort* port);
- // thread
- CWinThread* m_Thread;
- // synchronisation objects
- CRITICAL_SECTION m_csCommunicationSync;
- BOOL m_bThreadAlive;
- // handles
- HANDLE m_hShutdownEvent; //stop发生的事件
- HANDLE m_hComm; // read
- HANDLE m_hWriteEvent; // write
- // Event array.
- // One element is used for each event. There are two event handles for each port.
- // A Write event and a receive character event which is located in the overlapped structure (m_ov.hEvent).
- // There is a general shutdown when the port is closed.
- HANDLE m_hEventArray[3];
- // structures
- OVERLAPPED m_ov;
- COMMTIMEOUTS m_CommTimeouts;
- DCB m_dcb;
- // owner window
- CWnd* m_pOwner;
- // misc
- UINT m_nPortNr; //?????
- char* m_szWriteBuffer;
- DWORD m_dwCommEvents;
- DWORD m_nWriteBufferSize;
- int m_nWriteSize; //add by mrlong 2007-12-25
- };
- #endif __SERIALPORT_H__
/*
** FILENAME CSerialPort.h
**
** PURPOSE This class can read, write and watch one serial port.
** It sends messages to its owner when something happends on the port
** The class creates a thread for reading and writing so the main
** program is not blocked.
**
** CREATION DATE 15-09-1997
** LAST MODIFICATION 12-11-1997
**
** AUTHOR Remon Spekreijse
**
**
************************************************************************************
** author: mrlong date:2007-12-25
**
** 改进
** 1) 增加ClosePort
** 2) 增加 writetoProt() 两个方法
** 3) 增加 SendData 与 RecvData 方法
**************************************************************************************
***************************************************************************************
** author:liquanhai date:2011-11-04
** 改进
** 1)增加 ClosePort中交出控制权,防止死锁问题
** 2) 增加 ReceiveChar中防止线程死锁
*/
#ifndef __SERIALPORT_H__
#define __SERIALPORT_H__
#define WM_COMM_BREAK_DETECTED WM_USER+1 // A break was detected on input.
#define WM_COMM_CTS_DETECTED WM_USER+2 // The CTS (clear-to-send) signal changed state.
#define WM_COMM_DSR_DETECTED WM_USER+3 // The DSR (data-set-ready) signal changed state.
#define WM_COMM_ERR_DETECTED WM_USER+4 // A line-status error occurred. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY.
#define WM_COMM_RING_DETECTED WM_USER+5 // A ring indicator was detected.
#define WM_COMM_RLSD_DETECTED WM_USER+6 // The RLSD (receive-line-signal-detect) signal changed state.
#define WM_COMM_RXCHAR WM_USER+7 // A character was received and placed in the input buffer.
#define WM_COMM_RXFLAG_DETECTED WM_USER+8 // The event character was received and placed in the input buffer.
#define WM_COMM_TXEMPTY_DETECTED WM_USER+9 // The last character in the output buffer was sent.
class CSerialPort
{
public:
// contruction and destruction
CSerialPort();
virtual ~CSerialPort();
// port initialisation
BOOL InitPort(CWnd* pPortOwner, UINT portnr = 1, UINT baud = 19200,
char parity = 'N', UINT databits = 8, UINT stopsbits = 1,
DWORD dwCommEvents = EV_RXCHAR | EV_CTS, UINT nBufferSize = 512,
DWORD ReadIntervalTimeout = 1000,
DWORD ReadTotalTimeoutMultiplier = 1000,
DWORD ReadTotalTimeoutConstant = 1000,
DWORD WriteTotalTimeoutMultiplier = 1000,
DWORD WriteTotalTimeoutConstant = 1000);
// start/stop comm watching
BOOL StartMonitoring();
BOOL RestartMonitoring();
BOOL StopMonitoring();
DWORD GetWriteBufferSize();
DWORD GetCommEvents();
DCB GetDCB();
void WriteToPort(char* string);
void WriteToPort(char* string,int n); // add by mrlong 2007-12-25
void WriteToPort(LPCTSTR string); // add by mrlong 2007-12-25
void WriteToPort(BYTE* Buffer, int n);// add by mrlong
void ClosePort(); // add by mrlong 2007-12-2
void SendData(LPCTSTR lpszData, const int nLength); //串口发送函数 by mrlong 2008-2-15
BOOL RecvData(LPTSTR lpszData, const int nSize); //串口接收函数 by mrlong 2008-2-15
protected:
// protected memberfunctions
void ProcessErrorMessage(char* ErrorText);
static UINT CommThread(LPVOID pParam);
static void ReceiveChar(CSerialPort* port, COMSTAT comstat);
static void WriteChar(CSerialPort* port);
// thread
CWinThread* m_Thread;
// synchronisation objects
CRITICAL_SECTION m_csCommunicationSync;
BOOL m_bThreadAlive;
// handles
HANDLE m_hShutdownEvent; //stop发生的事件
HANDLE m_hComm; // read
HANDLE m_hWriteEvent; // write
// Event array.
// One element is used for each event. There are two event handles for each port.
// A Write event and a receive character event which is located in the overlapped structure (m_ov.hEvent).
// There is a general shutdown when the port is closed.
HANDLE m_hEventArray[3];
// structures
OVERLAPPED m_ov;
COMMTIMEOUTS m_CommTimeouts;
DCB m_dcb;
// owner window
CWnd* m_pOwner;
// misc
UINT m_nPortNr; //?????
char* m_szWriteBuffer;
DWORD m_dwCommEvents;
DWORD m_nWriteBufferSize;
int m_nWriteSize; //add by mrlong 2007-12-25
};
#endif __SERIALPORT_H__
源文件cpp文件如下:
- /*
- ** FILENAME CSerialPort.cpp
- **
- ** PURPOSE This class can read, write and watch one serial port.
- ** It sends messages to its owner when something happends on the port
- ** The class creates a thread for reading and writing so the main
- ** program is not blocked.
- **
- ** CREATION DATE 15-09-1997
- ** LAST MODIFICATION 12-11-1997
- **
- ** AUTHOR Remon Spekreijse
- **
- **
- */
- #include "stdafx.h"
- #include "SerialPort.h"
- #include
- //
- // Constructor
- //
- CSerialPort::CSerialPort()
- {
- m_hComm = NULL;
- // initialize overlapped structure members to zero
- m_ov.Offset = 0;
- m_ov.OffsetHigh = 0;
- // create events
- m_ov.hEvent = NULL;
- m_hWriteEvent = NULL;
- m_hShutdownEvent = NULL;
- m_szWriteBuffer = NULL;
- m_bThreadAlive = FALSE;
- m_nWriteSize = 1;
- }
- //
- // Delete dynamic memory
- //
- CSerialPort::~CSerialPort()
- {
- do
- {
- SetEvent(m_hShutdownEvent);
- } while (m_bThreadAlive);
- if (m_hComm != NULL)
- {
- CloseHandle(m_hComm);
- m_hComm = NULL;
- }
- // Close Handles
- if(m_hShutdownEvent!=NULL)
- CloseHandle( m_hShutdownEvent);
- if(m_ov.hEvent!=NULL)
- CloseHandle( m_ov.hEvent );
- if(m_hWriteEvent!=NULL)
- CloseHandle( m_hWriteEvent );
- TRACE("Thread ended\n");
- delete [] m_szWriteBuffer;
- }
- //
- // Initialize the port. This can be port 1 to 4.
- //
- //
- //parity:
- // n=none
- // e=even
- // o=odd
- // m=mark
- // s=space
- //data:
- // 5,6,7,8
- //stop:
- // 1,1.5,2
- //
- BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)
- UINT portnr, // portnumber (1..4)
- UINT baud, // baudrate
- char parity, // parity
- UINT databits, // databits
- UINT stopbits, // stopbits
- DWORD dwCommEvents, // EV_RXCHAR, EV_CTS etc
- UINT writebuffersize,// size to the writebuffer
- DWORD ReadIntervalTimeout,
- DWORD ReadTotalTimeoutMultiplier,
- DWORD ReadTotalTimeoutConstant,
- DWORD WriteTotalTimeoutMultiplier,
- DWORD WriteTotalTimeoutConstant )
- {
- assert(portnr > 0 && portnr < 5);
- assert(pPortOwner != NULL);
- // if the thread is alive: Kill
- if (m_bThreadAlive)
- {
- do
- {
- SetEvent(m_hShutdownEvent);
- } while (m_bThreadAlive);
- TRACE("Thread ended\n");
- }
- // create events
- if (m_ov.hEvent != NULL)
- ResetEvent(m_ov.hEvent);
- else
- m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
- if (m_hWriteEvent != NULL)
- ResetEvent(m_hWriteEvent);
- else
- m_hWriteEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
- if (m_hShutdownEvent != NULL)
- ResetEvent(m_hShutdownEvent);
- else
- m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
- // initialize the event objects
- m_hEventArray[0] = m_hShutdownEvent; // highest priority
- m_hEventArray[1] = m_ov.hEvent;
- m_hEventArray[2] = m_hWriteEvent;
- // initialize critical section
- InitializeCriticalSection(&m_csCommunicationSync);
- // set buffersize for writing and save the owner
- m_pOwner = pPortOwner;
- if (m_szWriteBuffer != NULL)
- delete [] m_szWriteBuffer;
- m_szWriteBuffer = new char[writebuffersize];
- m_nPortNr = portnr;
- m_nWriteBufferSize = writebuffersize;
- m_dwCommEvents = dwCommEvents;
- BOOL bResult = FALSE;
- char *szPort = new char[50];
- char *szBaud = new char[50];
- // now it critical!
- EnterCriticalSection(&m_csCommunicationSync);
- // if the port is already opened: close it
- if (m_hComm != NULL)
- {
- CloseHandle(m_hComm);
- m_hComm = NULL;
- }
- // prepare port strings
- sprintf(szPort, "COM%d", portnr);
- // stop is index 0 = 1 1=1.5 2=2
- int mystop;
- int myparity;
- switch(stopbits)
- {
- case 0:
- mystop = ONESTOPBIT;
- break;
- case 1:
- mystop = ONE5STOPBITS;
- break;
- case 2:
- mystop = TWOSTOPBITS;
- break;
- }
- myparity = 0;
- switch(parity)
- {
- case 'N':
- myparity = 0;
- break;
- case 'E':
- myparity = 1;
- break;
- case 'O':
- myparity = 2;
- break;
- case 'M':
- myparity = 3;
- break;
- case 'S':
- myparity = 4;
- break;
- }
- sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, mystop);
- // get a handle to the port
- m_hComm = CreateFile(szPort, // communication port string (COMX)
- GENERIC_READ | GENERIC_WRITE, // read/write types
- 0, // comm devices must be opened with exclusive access
- NULL, // no security attributes
- OPEN_EXISTING, // comm devices must use OPEN_EXISTING
- FILE_FLAG_OVERLAPPED, // Async I/O
- 0); // template must be 0 for comm devices
- if (m_hComm == INVALID_HANDLE_VALUE)
- {
- // port not found
- delete [] szPort;
- delete [] szBaud;
- return FALSE;
- }
- // set the timeout values
- m_CommTimeouts.ReadIntervalTimeout = ReadIntervalTimeout * 1000;
- m_CommTimeouts.ReadTotalTimeoutMultiplier = ReadTotalTimeoutMultiplier * 1000;
- m_CommTimeouts.ReadTotalTimeoutConstant = ReadTotalTimeoutConstant * 1000;
- m_CommTimeouts.WriteTotalTimeoutMultiplier = WriteTotalTimeoutMultiplier * 1000;
- m_CommTimeouts.WriteTotalTimeoutConstant = WriteTotalTimeoutConstant * 1000;
- // configure
- if (SetCommTimeouts(m_hComm, &m_CommTimeouts))
- {
- if (SetCommMask(m_hComm, dwCommEvents))
- {
- if (GetCommState(m_hComm, &m_dcb))
- {
- m_dcb.EvtChar = 'q';
- m_dcb.fRtsControl = RTS_CONTROL_ENABLE; // set RTS bit high!
- m_dcb.BaudRate = baud; // add by mrlong
- m_dcb.Parity = myparity;
- m_dcb.ByteSize = databits;
- m_dcb.StopBits = mystop;
- //if (BuildCommDCB(szBaud, &m_dcb))
- //{
- if (SetCommState(m_hComm, &m_dcb))
- ; // normal operation... continue
- else
- ProcessErrorMessage("SetCommState()");
- //}
- //else
- // ProcessErrorMessage("BuildCommDCB()");
- }
- else
- ProcessErrorMessage("GetCommState()");
- }
- else
- ProcessErrorMessage("SetCommMask()");
- }
- else
- ProcessErrorMessage("SetCommTimeouts()");
- delete [] szPort;
- delete [] szBaud;
- // flush the port
- PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
- // release critical section
- LeaveCriticalSection(&m_csCommunicationSync);
- TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr);
- return TRUE;
- }
- //
- // The CommThread Function.
- //
- UINT CSerialPort::CommThread(LPVOID pParam)
- {
- // Cast the void pointer passed to the thread back to
- // a pointer of CSerialPort class
- CSerialPort *port = (CSerialPort*)pParam;
- // Set the status variable in the dialog class to
- // TRUE to indicate the thread is running.
- port->m_bThreadAlive = TRUE;
- // Misc. variables
- DWORD BytesTransfered = 0;
- DWORD Event = 0;
- DWORD CommEvent = 0;
- DWORD dwError = 0;
- COMSTAT comstat;
- BOOL bResult = TRUE;
- // Clear comm buffers at startup
- if (port->m_hComm) // check if the port is opened
- PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
- // begin forever loop. This loop will run as long as the thread is alive.
- for (;;)
- {
- // Make a call to WaitCommEvent(). This call will return immediatly
- // because our port was created as an async port (FILE_FLAG_OVERLAPPED
- // and an m_OverlappedStructerlapped structure specified). This call will cause the
- // m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to
- // be placed in a non-signeled state if there are no bytes available to be read,
- // or to a signeled state if there are bytes available. If this event handle
- // is set to the non-signeled state, it will be set to signeled when a
- // character arrives at the port.
- // we do this for each port!
- bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov);
- if (!bResult)
- {
- // If WaitCommEvent() returns FALSE, process the last error to determin
- // the reason..
- switch (dwError = GetLastError())
- {
- case ERROR_IO_PENDING:
- {
- // This is a normal return value if there are no bytes
- // to read at the port.
- // Do nothing and continue
- break;
- }
- case 87:
- {
- // Under Windows NT, this value is returned for some reason.
- // I have not investigated why, but it is also a valid reply
- // Also do nothing and continue.
- break;
- }
- default:
- {
- // All other error codes indicate a serious error has
- // occured. Process this error.
- port->ProcessErrorMessage("WaitCommEvent()");
- break;
- }
- }
- }
- else
- {
- // If WaitCommEvent() returns TRUE, check to be sure there are
- // actually bytes in the buffer to read.
- //
- // If you are reading more than one byte at a time from the buffer
- // (which this program does not do) you will have the situation occur
- // where the first byte to arrive will cause the WaitForMultipleObjects()
- // function to stop waiting. The WaitForMultipleObjects() function
- // resets the event handle in m_OverlappedStruct.hEvent to the non-signelead state
- // as it returns.
- //
- // If in the time between the reset of this event and the call to
- // ReadFile() more bytes arrive, the m_OverlappedStruct.hEvent handle will be set again
- // to the signeled state. When the call to ReadFile() occurs, it will
- // read all of the bytes from the buffer, and the program will
- // loop back around to WaitCommEvent().
- //
- // At this point you will be in the situation where m_OverlappedStruct.hEvent is set,
- // but there are no bytes available to read. If you proceed and call
- // ReadFile(), it will return immediatly due to the async port setup, but
- // GetOverlappedResults() will not return until the next character arrives.
- //
- // It is not desirable for the GetOverlappedResults() function to be in
- // this state. The thread shutdown event (event 0) and the WriteFile()
- // event (Event2) will not work if the thread is blocked by GetOverlappedResults().
- //
- // The solution to this is to check the buffer with a call to ClearCommError().
- // This call will reset the event handle, and if there are no bytes to read
- // we can loop back through WaitCommEvent() again, then proceed.
- // If there are really bytes to read, do nothing and proceed.
- bResult = ClearCommError(port->m_hComm, &dwError, &comstat);
- if (comstat.cbInQue == 0)
- continue;
- } // end if bResult
- // Main wait function. This function will normally block the thread
- // until one of nine events occur that require action.
- Event = WaitForMultipleObjects(3, port->m_hEventArray, FALSE, INFINITE);
- switch (Event)
- {
- case 0:
- {
- // Shutdown event. This is event zero so it will be
- // the higest priority and be serviced first.
- port->m_bThreadAlive = FALSE;
- // Kill this thread. break is not needed, but makes me feel better.
- AfxEndThread(100);
- break;
- }
- case 1: // read event
- {
- GetCommMask(port->m_hComm, &CommEvent);
- if (CommEvent & EV_RXCHAR) //接收到字符,并置于输入缓冲区中
- ReceiveChar(port, comstat);
- if (CommEvent & EV_CTS) //CTS信号状态发生变化
- ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_CTS_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
- if (CommEvent & EV_RXFLAG) //接收到事件字符,并置于输入缓冲区中
- ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RXFLAG_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
- if (CommEvent & EV_BREAK) //输入中发生中断
- ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_BREAK_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
- if (CommEvent & EV_ERR) //发生线路状态错误,线路状态错误包括CE_FRAME,CE_OVERRUN和CE_RXPARITY
- ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_ERR_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
- if (CommEvent & EV_RING) //检测到振铃指示
- ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RING_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
- break;
- }
- case 2: // write event
- {
- // Write character event from port
- WriteChar(port);
- break;
- }
- } // end switch
- } // close forever loop
- return 0;
- }
- //
- // start comm watching
- //
- BOOL CSerialPort::StartMonitoring()
- {
- if (!(m_Thread = AfxBeginThread(CommThread, this)))
- return FALSE;
- TRACE("Thread started\n");
- return TRUE;
- }
- //
- // Restart the comm thread
- //
- BOOL CSerialPort::RestartMonitoring()
- {
- TRACE("Thread resumed\n");
- m_Thread->ResumeThread();
- return TRUE;
- }
- //
- // Suspend the comm thread
- //
- BOOL CSerialPort::StopMonitoring()
- {
- TRACE("Thread suspended\n");
- m_Thread->SuspendThread();
- return TRUE;
- }
- //
- // If there is a error, give the right message
- //
- void CSerialPort::ProcessErrorMessage(char* ErrorText)
- {
- char *Temp = new char[200];
- LPVOID lpMsgBuf;
- FormatMessage(
- FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
- NULL,
- GetLastError(),
- MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
- (LPTSTR) &lpMsgBuf,
- 0,
- NULL
- );
- sprintf(Temp, "WARNING: %s Failed with the following error: \n%s\nPort: %d\n", (char*)ErrorText, lpMsgBuf, m_nPortNr);
- MessageBox(NULL, Temp, "Application Error", MB_ICONSTOP);
- LocalFree(lpMsgBuf);
- delete[] Temp;
- }
- //
- // Write a character.
- //
- void CSerialPort::WriteChar(CSerialPort* port)
- {
- BOOL bWrite = TRUE;
- BOOL bResult = TRUE;
- DWORD BytesSent = 0;
- DWORD SendLen = port->m_nWriteSize;
- ResetEvent(port->m_hWriteEvent);
- // Gain ownership of the critical section
- EnterCriticalSection(&port->m_csCommunicationSync);
- if (bWrite)
- {
- // Initailize variables
- port->m_ov.Offset = 0;
- port->m_ov.OffsetHigh = 0;
- // Clear buffer
- PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
- bResult = WriteFile(port->m_hComm, // Handle to COMM Port
- port->m_szWriteBuffer, // Pointer to message buffer in calling finction
- SendLen, // add by mrlong
- //strlen((char*)port->m_szWriteBuffer), // Length of message to send
- &BytesSent, // Where to store the number of bytes sent
- &port->m_ov); // Overlapped structure
- // deal with any error codes
- if (!bResult)
- {
- DWORD dwError = GetLastError();
- switch (dwError)
- {
- case ERROR_IO_PENDING:
- {
- // continue to GetOverlappedResults()
- BytesSent = 0;
- bWrite = FALSE;
- break;
- }
- default:
- {
- // all other error codes
- port->ProcessErrorMessage("WriteFile()");
- }
- }
- }
- else
- {
- LeaveCriticalSection(&port->m_csCommunicationSync);
- }
- } // end if(bWrite)
- if (!bWrite)
- {
- bWrite = TRUE;
- bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port
- &port->m_ov, // Overlapped structure
- &BytesSent, // Stores number of bytes sent
- TRUE); // Wait flag
- LeaveCriticalSection(&port->m_csCommunicationSync);
- // deal with the error code
- if (!bResult)
- {
- port->ProcessErrorMessage("GetOverlappedResults() in WriteFile()");
- }
- } // end if (!bWrite)
- // Verify that the data size send equals what we tried to send
- if (BytesSent != SendLen /*strlen((char*)port->m_szWriteBuffer)*/) // add by
- {
- TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent, strlen((char*)port->m_szWriteBuffer));
- }
- }
- //
- // Character received. Inform the owner
- //
- void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat)
- {
- BOOL bRead = TRUE;
- BOOL bResult = TRUE;
- DWORD dwError = 0;
- DWORD BytesRead = 0;
- unsigned char RXBuff;
- for (;;)
- {
- //add by liquanhai 2011-11-06 防止死锁
- if(WaitForSingleObject(port->m_hShutdownEvent,0)==WAIT_OBJECT_0)
- return;
- // Gain ownership of the comm port critical section.
- // This process guarantees no other part of this program
- // is using the port object.
- EnterCriticalSection(&port->m_csCommunicationSync);
- // ClearCommError() will update the COMSTAT structure and
- // clear any other errors.
- bResult = ClearCommError(port->m_hComm, &dwError, &comstat);
- LeaveCriticalSection(&port->m_csCommunicationSync);
- // start forever loop. I use this type of loop because I
- // do not know at runtime how many loops this will have to
- // run. My solution is to start a forever loop and to
- // break out of it when I have processed all of the
- // data available. Be careful with this approach and
- // be sure your loop will exit.
- // My reasons for this are not as clear in this sample
- // as it is in my production code, but I have found this
- // solutiion to be the most efficient way to do this.
- if (comstat.cbInQue == 0)
- {
- // break out when all bytes have been read
- break;
- }
- EnterCriticalSection(&port->m_csCommunicationSync);
- if (bRead)
- {
- bResult = ReadFile(port->m_hComm, // Handle to COMM port
- &RXBuff, // RX Buffer Pointer
- 1, // Read one byte
- &BytesRead, // Stores number of bytes read
- &port->m_ov); // pointer to the m_ov structure
- // deal with the error code
- if (!bResult)
- {
- switch (dwError = GetLastError())
- {
- case ERROR_IO_PENDING:
- {
- // asynchronous i/o is still in progress
- // Proceed on to GetOverlappedResults();
- bRead = FALSE;
- break;
- }
- default:
- {
- // Another error has occured. Process this error.
- port->ProcessErrorMessage("ReadFile()");
- break;
- }
- }
- }
- else
- {
- // ReadFile() returned complete. It is not necessary to call GetOverlappedResults()
- bRead = TRUE;
- }
- } // close if (bRead)
- if (!bRead)
- {
- bRead = TRUE;
- bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port
- &port->m_ov, // Overlapped structure
- &BytesRead, // Stores number of bytes read
- TRUE); // Wait flag
- // deal with the error code
- if (!bResult)
- {
- port->ProcessErrorMessage("GetOverlappedResults() in ReadFile()");
- }
- } // close if (!bRead)
- LeaveCriticalSection(&port->m_csCommunicationSync);
- // notify parent that a byte was received
- ::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_RXCHAR, (WPARAM) RXBuff, (LPARAM) port->m_nPortNr);
- } // end forever loop
- }
- //
- // Write a string to the port
- //
- void CSerialPort::WriteToPort(char* string)
- {
- assert(m_hComm != 0);
- memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
- strcpy(m_szWriteBuffer, string);
- m_nWriteSize=strlen(string); // add by mrlong
- // set event for write
- SetEvent(m_hWriteEvent);
- }
- //
- // Return the device control block
- //
- DCB CSerialPort::GetDCB()
- {
- return m_dcb;
- }
- //
- // Return the communication event masks
- //
- DWORD CSerialPort::GetCommEvents()
- {
- return m_dwCommEvents;
- }
- //
- // Return the output buffer size
- //
- DWORD CSerialPort::GetWriteBufferSize()
- {
- return m_nWriteBufferSize;
- }
- void CSerialPort::ClosePort()
- {
/*
** FILENAME CSerialPort.cpp
**
** PURPOSE This class can read, write and watch one serial port.
** It sends messages to its owner when something happends on the port
** The class creates a thread for reading and writing so the main
** program is not blocked.
**
** CREATION DATE 15-09-1997
** LAST MODIFICATION 12-11-1997
**
** AUTHOR Remon Spekreijse
**
**
*/
#include "stdafx.h"
#include "SerialPort.h"
#include
//
// Constructor
//
CSerialPort::CSerialPort()
{
m_hComm = NULL;
// initialize overlapped structure members to zero
m_ov.Offset = 0;
m_ov.OffsetHigh = 0;
// create events
m_ov.hEvent = NULL;
m_hWriteEvent = NULL;
m_hShutdownEvent = NULL;
m_szWriteBuffer = NULL;
m_bThreadAlive = FALSE;
m_nWriteSize = 1;
}
//
// Delete dynamic memory
//
CSerialPort::~CSerialPort()
{
do
{
SetEvent(m_hShutdownEvent);
} while (m_bThreadAlive);
if (m_hComm != NULL)
{
CloseHandle(m_hComm);
m_hComm = NULL;
}
// Close Handles
if(m_hShutdownEvent!=NULL)
CloseHandle( m_hShutdownEvent);
if(m_ov.hEvent!=NULL)
CloseHandle( m_ov.hEvent );
if(m_hWriteEvent!=NULL)
CloseHandle( m_hWriteEvent );
TRACE("Thread ended\n");
delete [] m_szWriteBuffer;
}
//
// Initialize the port. This can be port 1 to 4.
//
//
//parity:
// n=none
// e=even
// o=odd
// m=mark
// s=space
//data:
// 5,6,7,8
//stop:
// 1,1.5,2
//
BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)
UINT portnr, // portnumber (1..4)
UINT baud, // baudrate
char parity, // parity
UINT databits, // databits
UINT stopbits, // stopbits
DWORD dwCommEvents, // EV_RXCHAR, EV_CTS etc
UINT writebuffersize,// size to the writebuffer
DWORD ReadIntervalTimeout,
DWORD ReadTotalTimeoutMultiplier,
DWORD ReadTotalTimeoutConstant,
DWORD WriteTotalTimeoutMultiplier,
DWORD WriteTotalTimeoutConstant )
{
assert(portnr > 0 && portnr < 5);
assert(pPortOwner != NULL);
// if the thread is alive: Kill
if (m_bThreadAlive)
{
do
{
SetEvent(m_hShutdownEvent);
} while (m_bThreadAlive);
TRACE("Thread ended\n");
}
// create events
if (m_ov.hEvent != NULL)
ResetEvent(m_ov.hEvent);
else
m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (m_hWriteEvent != NULL)
ResetEvent(m_hWriteEvent);
else
m_hWriteEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (m_hShutdownEvent != NULL)
ResetEvent(m_hShutdownEvent);
else
m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
// initialize the event objects
m_hEventArray[0] = m_hShutdownEvent; // highest priority
m_hEventArray[1] = m_ov.hEvent;
m_hEventArray[2] = m_hWriteEvent;
// initialize critical section
InitializeCriticalSection(&m_csCommunicationSync);
// set buffersize for writing and save the owner
m_pOwner = pPortOwner;
if (m_szWriteBuffer != NULL)
delete [] m_szWriteBuffer;
m_szWriteBuffer = new char[writebuffersize];
m_nPortNr = portnr;
m_nWriteBufferSize = writebuffersize;
m_dwCommEvents = dwCommEvents;
BOOL bResult = FALSE;
char *szPort = new char[50];
char *szBaud = new char[50];
// now it critical!
EnterCriticalSection(&m_csCommunicationSync);
// if the port is already opened: close it
if (m_hComm != NULL)
{
CloseHandle(m_hComm);
m_hComm = NULL;
}
// prepare port strings
sprintf(szPort, "COM%d", portnr);
// stop is index 0 = 1 1=1.5 2=2
int mystop;
int myparity;
switch(stopbits)
{
case 0:
mystop = ONESTOPBIT;
break;
case 1:
mystop = ONE5STOPBITS;
break;
case 2:
mystop = TWOSTOPBITS;
break;
}
myparity = 0;
switch(parity)
{
case 'N':
myparity = 0;
break;
case 'E':
myparity = 1;
break;
case 'O':
myparity = 2;
break;
case 'M':
myparity = 3;
break;
case 'S':
myparity = 4;
break;
}
sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, mystop);
// get a handle to the port
m_hComm = CreateFile(szPort, // communication port string (COMX)
GENERIC_READ | GENERIC_WRITE, // read/write types
0, // comm devices must be opened with exclusive access
NULL, // no security attributes
OPEN_EXISTING, // comm devices must use OPEN_EXISTING
FILE_FLAG_OVERLAPPED, // Async I/O
0); // template must be 0 for comm devices
if (m_hComm == INVALID_HANDLE_VALUE)
{
// port not found
delete [] szPort;
delete [] szBaud;
return FALSE;
}
// set the timeout values
m_CommTimeouts.ReadIntervalTimeout = ReadIntervalTimeout * 1000;
m_CommTimeouts.ReadTotalTimeoutMultiplier = ReadTotalTimeoutMultiplier * 1000;
m_CommTimeouts.ReadTotalTimeoutConstant = ReadTotalTimeoutConstant * 1000;
m_CommTimeouts.WriteTotalTimeoutMultiplier = WriteTotalTimeoutMultiplier * 1000;
m_CommTimeouts.WriteTotalTimeoutConstant = WriteTotalTimeoutConstant * 1000;
// configure
if (SetCommTimeouts(m_hComm, &m_CommTimeouts))
{
if (SetCommMask(m_hComm, dwCommEvents))
{
if (GetCommState(m_hComm, &m_dcb))
{
m_dcb.EvtChar = 'q';
m_dcb.fRtsControl = RTS_CONTROL_ENABLE; // set RTS bit high!
m_dcb.BaudRate = baud; // add by mrlong
m_dcb.Parity = myparity;
m_dcb.ByteSize = databits;
m_dcb.StopBits = mystop;
//if (BuildCommDCB(szBaud, &m_dcb))
//{
if (SetCommState(m_hComm, &m_dcb))
; // normal operation... continue
else
ProcessErrorMessage("SetCommState()");
//}
//else
// ProcessErrorMessage("BuildCommDCB()");
}
else
ProcessErrorMessage("GetCommState()");
}
else
ProcessErrorMessage("SetCommMask()");
}
else
ProcessErrorMessage("SetCommTimeouts()");
delete [] szPort;
delete [] szBaud;
// flush the port
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
// release critical section
LeaveCriticalSection(&m_csCommunicationSync);
TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr);
return TRUE;
}
//
// The CommThread Function.
//
UINT CSerialPort::CommThread(LPVOID pParam)
{
// Cast the void pointer passed to the thread back to
// a pointer of CSerialPort class
CSerialPort *port = (CSerialPort*)pParam;
// Set the status variable in the dialog class to
// TRUE to indicate the thread is running.
port->m_bThreadAlive = TRUE;
// Misc. variables
DWORD BytesTransfered = 0;
DWORD Event = 0;
DWORD CommEvent = 0;
DWORD dwError = 0;
COMSTAT comstat;
BOOL bResult = TRUE;
// Clear comm buffers at startup
if (port->m_hComm) // check if the port is opened
PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
// begin forever loop. This loop will run as long as the thread is alive.
for (;;)
{
// Make a call to WaitCommEvent(). This call will return immediatly
// because our port was created as an async port (FILE_FLAG_OVERLAPPED
// and an m_OverlappedStructerlapped structure specified). This call will cause the
// m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to
// be placed in a non-signeled state if there are no bytes available to be read,
// or to a signeled state if there are bytes available. If this event handle
// is set to the non-signeled state, it will be set to signeled when a
// character arrives at the port.
// we do this for each port!
bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov);
if (!bResult)
{
// If WaitCommEvent() returns FALSE, process the last error to determin
// the reason..
switch (dwError = GetLastError())
{
case ERROR_IO_PENDING:
{
// This is a normal return value if there are no bytes
// to read at the port.
// Do nothing and continue
break;
}
case 87:
{
// Under Windows NT, this value is returned for some reason.
// I have not investigated why, but it is also a valid reply
// Also do nothing and continue.
break;
}
default:
{
// All other error codes indicate a serious error has
// occured. Process this error.
port->ProcessErrorMessage("WaitCommEvent()");
break;
}
}
}
else
{
// If WaitCommEvent() returns TRUE, check to be sure there are
// actually bytes in the buffer to read.
//
// If you are reading more than one byte at a time from the buffer
// (which this program does not do) you will have the situation occur
// where the first byte to arrive will cause the WaitForMultipleObjects()
// function to stop waiting. The WaitForMultipleObjects() function
// resets the event handle in m_OverlappedStruct.hEvent to the non-signelead state
// as it returns.
//
// If in the time between the reset of this event and the call to
// ReadFile() more bytes arrive, the m_OverlappedStruct.hEvent handle will be set again
// to the signeled state. When the call to ReadFile() occurs, it will
// read all of the bytes from the buffer, and the program will
// loop back around to WaitCommEvent().
//
// At this point you will be in the situation where m_OverlappedStruct.hEvent is set,
// but there are no bytes available to read. If you proceed and call
// ReadFile(), it will return immediatly due to the async port setup, but
// GetOverlappedResults() will not return until the next character arrives.
//
// It is not desirable for the GetOverlappedResults() function to be in
// this state. The thread shutdown event (event 0) and the WriteFile()
// event (Event2) will not work if the thread is blocked by GetOverlappedResults().
//
// The solution to this is to check the buffer with a call to ClearCommError().
// This call will reset the event handle, and if there are no bytes to read
// we can loop back through WaitCommEvent() again, then proceed.
// If there are really bytes to read, do nothing and proceed.
bResult = ClearCommError(port->m_hComm, &dwError, &comstat);
if (comstat.cbInQue == 0)
continue;
} // end if bResult
// Main wait function. This function will normally block the thread
// until one of nine events occur that require action.
Event = WaitForMultipleObjects(3, port->m_hEventArray, FALSE, INFINITE);
switch (Event)
{
case 0:
{
// Shutdown event. This is event zero so it will be
// the higest priority and be serviced first.
port->m_bThreadAlive = FALSE;
// Kill this thread. break is not needed, but makes me feel better.
AfxEndThread(100);
break;
}
case 1: // read event
{
GetCommMask(port->m_hComm, &CommEvent);
if (CommEvent & EV_RXCHAR) //接收到字符,并置于输入缓冲区中
ReceiveChar(port, comstat);
if (CommEvent & EV_CTS) //CTS信号状态发生变化
::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_CTS_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
if (CommEvent & EV_RXFLAG) //接收到事件字符,并置于输入缓冲区中
::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RXFLAG_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
if (CommEvent & EV_BREAK) //输入中发生中断
::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_BREAK_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
if (CommEvent & EV_ERR) //发生线路状态错误,线路状态错误包括CE_FRAME,CE_OVERRUN和CE_RXPARITY
::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_ERR_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
if (CommEvent & EV_RING) //检测到振铃指示
::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RING_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
break;
}
case 2: // write event
{
// Write character event from port
WriteChar(port);
break;
}
} // end switch
} // close forever loop
return 0;
}
//
// start comm watching
//
BOOL CSerialPort::StartMonitoring()
{
if (!(m_Thread = AfxBeginThread(CommThread, this)))
return FALSE;
TRACE("Thread started\n");
return TRUE;
}
//
// Restart the comm thread
//
BOOL CSerialPort::RestartMonitoring()
{
TRACE("Thread resumed\n");
m_Thread->ResumeThread();
return TRUE;
}
//
// Suspend the comm thread
//
BOOL CSerialPort::StopMonitoring()
{
TRACE("Thread suspended\n");
m_Thread->SuspendThread();
return TRUE;
}
//
// If there is a error, give the right message
//
void CSerialPort::ProcessErrorMessage(char* ErrorText)
{
char *Temp = new char[200];
LPVOID lpMsgBuf;
FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL,
GetLastError(),
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
(LPTSTR) &lpMsgBuf,
0,
NULL
);
sprintf(Temp, "WARNING: %s Failed with the following error: \n%s\nPort: %d\n", (char*)ErrorText, lpMsgBuf, m_nPortNr);
MessageBox(NULL, Temp, "Application Error", MB_ICONSTOP);
LocalFree(lpMsgBuf);
delete[] Temp;
}
//
// Write a character.
//
void CSerialPort::WriteChar(CSerialPort* port)
{
BOOL bWrite = TRUE;
BOOL bResult = TRUE;
DWORD BytesSent = 0;
DWORD SendLen = port->m_nWriteSize;
ResetEvent(port->m_hWriteEvent);
// Gain ownership of the critical section
EnterCriticalSection(&port->m_csCommunicationSync);
if (bWrite)
{
// Initailize variables
port->m_ov.Offset = 0;
port->m_ov.OffsetHigh = 0;
// Clear buffer
PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
bResult = WriteFile(port->m_hComm, // Handle to COMM Port
port->m_szWriteBuffer, // Pointer to message buffer in calling finction
SendLen, // add by mrlong
//strlen((char*)port->m_szWriteBuffer), // Length of message to send
&BytesSent, // Where to store the number of bytes sent
&port->m_ov); // Overlapped structure
// deal with any error codes
if (!bResult)
{
DWORD dwError = GetLastError();
switch (dwError)
{
case ERROR_IO_PENDING:
{
// continue to GetOverlappedResults()
BytesSent = 0;
bWrite = FALSE;
break;
}
default:
{
// all other error codes
port->ProcessErrorMessage("WriteFile()");
}
}
}
else
{
LeaveCriticalSection(&port->m_csCommunicationSync);
}
} // end if(bWrite)
if (!bWrite)
{
bWrite = TRUE;
bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port
&port->m_ov, // Overlapped structure
&BytesSent, // Stores number of bytes sent
TRUE); // Wait flag
LeaveCriticalSection(&port->m_csCommunicationSync);
// deal with the error code
if (!bResult)
{
port->ProcessErrorMessage("GetOverlappedResults() in WriteFile()");
}
} // end if (!bWrite)
// Verify that the data size send equals what we tried to send
if (BytesSent != SendLen /*strlen((char*)port->m_szWriteBuffer)*/) // add by
{
TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent, strlen((char*)port->m_szWriteBuffer));
}
}
//
// Character received. Inform the owner
//
void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat)
{
BOOL bRead = TRUE;
BOOL bResult = TRUE;
DWORD dwError = 0;
DWORD BytesRead = 0;
unsigned char RXBuff;
for (;;)
{
//add by liquanhai 2011-11-06 防止死锁
if(WaitForSingleObject(port->m_hShutdownEvent,0)==WAIT_OBJECT_0)
return;
// Gain ownership of the comm port critical section.
// This process guarantees no other part of this program
// is using the port object.
EnterCriticalSection(&port->m_csCommunicationSync);
// ClearCommError() will update the COMSTAT structure and
// clear any other errors.
bResult = ClearCommError(port->m_hComm, &dwError, &comstat);
LeaveCriticalSection(&port->m_csCommunicationSync);
// start forever loop. I use this type of loop because I
// do not know at runtime how many loops this will have to
// run. My solution is to start a forever loop and to
// break out of it when I have processed all of the
// data available. Be careful with this approach and
// be sure your loop will exit.
// My reasons for this are not as clear in this sample
// as it is in my production code, but I have found this
// solutiion to be the most efficient way to do this.
if (comstat.cbInQue == 0)
{
// break out when all bytes have been read
break;
}
EnterCriticalSection(&port->m_csCommunicationSync);
if (bRead)
{
bResult = ReadFile(port->m_hComm, // Handle to COMM port
&RXBuff, // RX Buffer Pointer
1, // Read one byte
&BytesRead, // Stores number of bytes read
&port->m_ov); // pointer to the m_ov structure
// deal with the error code
if (!bResult)
{
switch (dwError = GetLastError())
{
case ERROR_IO_PENDING:
{
// asynchronous i/o is still in progress
// Proceed on to GetOverlappedResults();
bRead = FALSE;
break;
}
default:
{
// Another error has occured. Process this error.
port->ProcessErrorMessage("ReadFile()");
break;
}
}
}
else
{
// ReadFile() returned complete. It is not necessary to call GetOverlappedResults()
bRead = TRUE;
}
} // close if (bRead)
if (!bRead)
{
bRead = TRUE;
bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port
&port->m_ov, // Overlapped structure
&BytesRead, // Stores number of bytes read
TRUE); // Wait flag
// deal with the error code
if (!bResult)
{
port->ProcessErrorMessage("GetOverlappedResults() in ReadFile()");
}
} // close if (!bRead)
LeaveCriticalSection(&port->m_csCommunicationSync);
// notify parent that a byte was received
::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_RXCHAR, (WPARAM) RXBuff, (LPARAM) port->m_nPortNr);
} // end forever loop
}
//
// Write a string to the port
//
void CSerialPort::WriteToPort(char* string)
{
assert(m_hComm != 0);
memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
strcpy(m_szWriteBuffer, string);
m_nWriteSize=strlen(string); // add by mrlong
// set event for write
SetEvent(m_hWriteEvent);
}
//
// Return the device control block
//
DCB CSerialPort::GetDCB()
{
return m_dcb;
}
//
// Return the communication event masks
//
DWORD CSerialPort::GetCommEvents()
{
return m_dwCommEvents;
}
//
// Return the output buffer size
//
DWORD CSerialPort::GetWriteBufferSize()
{
return m_nWriteBufferSize;
}
void CSerialPort::ClosePort()
{
- MSG message;
- do
- {
- SetEvent(m_hShutdownEvent);
- if(::PeekMessage(&message,m_pOwner->m_hWnd,0,0,PM_REMOVE))
- {
- ::TranslateMessage(&message);
- ::DispatchMessage(&message);
- }
- } while (m_bThreadAlive);
- // if the port is still opened: close it
- if (m_hComm != NULL)
- {
- CloseHandle(m_hComm);
- m_hComm = NULL;
- }
- // Close Handles
- if(m_hShutdownEvent!=NULL)
- ResetEvent(m_hShutdownEvent);
- if(m_ov.hEvent!=NULL)
- ResetEvent(m_ov.hEvent);
- if(m_hWriteEvent!=NULL)
- ResetEvent(m_hWriteEvent);
- //delete [] m_szWriteBuffer;
- }
- void CSerialPort::WriteToPort(char* string,int n)
- {
- assert(m_hComm != 0);
- memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
- memcpy(m_szWriteBuffer, string, n);
- m_nWriteSize = n;
- // set event for write
- SetEvent(m_hWriteEvent);
- }
- void CSerialPort::WriteToPort(LPCTSTR string)
- {
- assert(m_hComm != 0);
- memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
- strcpy(m_szWriteBuffer, string);
- m_nWriteSize=strlen(string);
- // set event for write
- SetEvent(m_hWriteEvent);
- }
- void CSerialPort::WriteToPort(BYTE* Buffer, int n)
- {
- assert(m_hComm != 0);
- memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
- int i;
- for(i=0; i
- {
- m_szWriteBuffer[i] = Buffer[i];
- }
- m_nWriteSize=n;
- // set event for write
- SetEvent(m_hWriteEvent);
- }
- void CSerialPort::SendData(LPCTSTR lpszData, const int nLength)
- {
- assert(m_hComm != 0);
- memset(m_szWriteBuffer, 0, nLength);
- strcpy(m_szWriteBuffer, lpszData);
- m_nWriteSize=nLength;
- // set event for write
- SetEvent(m_hWriteEvent);
- }
- BOOL CSerialPort::RecvData(LPTSTR lpszData, const int nSize)
- {
- //
- //接收数据
- //
- assert(m_hComm!=0);
- memset(lpszData,0,nSize);
- DWORD mylen = 0;
- DWORD mylen2 = 0;
- while (mylen
- if(!ReadFile(m_hComm,lpszData,nSize,&mylen2,NULL))
- return FALSE;
- mylen += mylen2;
- }
- return TRUE;
- }
MSG message;
do
{
SetEvent(m_hShutdownEvent);
if(::PeekMessage(&message,m_pOwner->m_hWnd,0,0,PM_REMOVE))
{
::TranslateMessage(&message);
::DispatchMessage(&message);
}
} while (m_bThreadAlive);
// if the port is still opened: close it
if (m_hComm != NULL)
{
CloseHandle(m_hComm);
m_hComm = NULL;
}
// Close Handles
if(m_hShutdownEvent!=NULL)
ResetEvent(m_hShutdownEvent);
if(m_ov.hEvent!=NULL)
ResetEvent(m_ov.hEvent);
if(m_hWriteEvent!=NULL)
ResetEvent(m_hWriteEvent);
//delete [] m_szWriteBuffer;
}
void CSerialPort::WriteToPort(char* string,int n)
{
assert(m_hComm != 0);
memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
memcpy(m_szWriteBuffer, string, n);
m_nWriteSize = n;
// set event for write
SetEvent(m_hWriteEvent);
}
void CSerialPort::WriteToPort(LPCTSTR string)
{
assert(m_hComm != 0);
memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
strcpy(m_szWriteBuffer, string);
m_nWriteSize=strlen(string);
// set event for write
SetEvent(m_hWriteEvent);
}
void CSerialPort::WriteToPort(BYTE* Buffer, int n)
{
assert(m_hComm != 0);
memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
int i;
for(i=0; i
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