解决了关闭串口时死锁的CSerialPort类

/* ** 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 ** ** 2007-12-25 mrlong https://code.google.com/p/mycom/ ** 2011-11-06 liquanhai http://blog.csdn.net/liquanhai/article/details/6941574 ** 2013-12-04 viruscamp ** 2014-01-10 itas http://blog.csdn.net/itas109 ** 2014-12-18 liquanhai http://blog.csdn.net/liquanhai/article/details/6941574 */ #include "stdafx.h" #include "SerialPort.h" #include <assert.h> int m_nComArray[20]; // // Constructor // CSerialPort::CSerialPort() { m_hComm = NULL; // initialize overlapped structure members to zero ///初始化异步结构体 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; m_bIsSuspened = FALSE; } // // Delete dynamic memory // CSerialPort::~CSerialPort() { do { SetEvent(m_hShutdownEvent); } 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) 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 MaxSerialPortNum. ///初始化串口。只能是1-MaxSerialPortNum // //parity: // n=none // e=even // o=odd // m=mark // s=space //data: // 5,6,7,8 //stop: // 1,1.5,2 // BOOL CSerialPort::InitPort(HWND pPortOwner, // the owner (CWnd) of the port (receives message) UINT portnr, // portnumber (1..MaxSerialPortNum) 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 < 200); 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 ///事件数组初始化，设定优先级别 m_hEventArray[0] = m_hShutdownEvent; // highest priority m_hEventArray[1] = m_ov.hEvent; m_hEventArray[2] = m_hWriteEvent; // initialize critical section ///初始化临界资源 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]; /* 多个线程操作相同的数据时，一般是需要按顺序访问的，否则会引导数据错乱， 无法控制数据，变成随机变量。为解决这个问题，就需要引入互斥变量，让每 个线程都按顺序地访问变量。这样就需要使用EnterCriticalSection和 LeaveCriticalSection函数。 */ // now it critical! EnterCriticalSection(&m_csCommunicationSync); // if the port is already opened: close it ///串口已打开就关掉 if (m_hComm != NULL) { CloseHandle(m_hComm); m_hComm = NULL; } // prepare port strings sprintf(szPort, "\\\\.\\COM%d", portnr);///可以显示COM10以上端口//add by itas109 2014-01-09 // 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; parity = toupper(parity); switch(parity) { case 'N': myparity = 0; break; case 'O': myparity = 1; break; case 'E': 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 /* 通信程序在CreateFile处指定串口设备及相关的操作属性，再返回一个句柄， 该句柄将被用于后续的通信操作，并贯穿整个通信过程串口打开后，其属性 被设置为默认值，根据具体需要，通过调用GetCommState(hComm,&&dcb)读取 当前串口设备控制块DCB设置，修改后通过SetCommState(hComm,&&dcb)将其写 入。运用ReadFile()与WriteFile()这两个API函数实现串口读写操作，若为异 步通信方式，两函数中最后一个参数为指向OVERLAPPED结构的非空指针，在读 写函数返回值为FALSE的情况下，调用GetLastError()函数，返回值为ERROR_IO_PENDING， 表明I/O操作悬挂，即操作转入后台继续执行。此时，可以用WaitForSingleObject() 来等待结束信号并设置最长等待时间 */ 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 ///创建失败 if (m_hComm == INVALID_HANDLE_VALUE) { // port not found delete [] szPort; delete [] szBaud; return FALSE; } // set the timeout values ///设置超时 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 ///配置 ///分别调用Windows API设置串口参数 if (SetCommTimeouts(m_hComm, &m_CommTimeouts))///设置超时 { /* 若对端口数据的响应时间要求较严格，可采用事件驱动方式。 事件驱动方式通过设置事件通知，当所希望的事件发生时，Windows 发出该事件已发生的通知，这与DOS环境下的中断方式很相似。Windows 定义了9种串口通信事件，较常用的有以下三种： EV_RXCHAR:接收到一个字节，并放入输入缓冲区； EV_TXEMPTY:输出缓冲区中的最后一个字符，发送出去； EV_RXFLAG:接收到事件字符(DCB结构中EvtChar成员)，放入输入缓冲区 在用SetCommMask()指定了有用的事件后，应用程序可调用WaitCommEvent()来等待事 件的发生。SetCommMask(hComm,0)可使WaitCommEvent()中止 */ if (SetCommMask(m_hComm, dwCommEvents))///设置通信事件 { if (GetCommState(m_hComm, &m_dcb))///获取当前DCB参数 { 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))///填写DCB结构 { if (SetCommState(m_hComm, &m_dcb))///配置DCB ; // normal operation... continue else ProcessErrorMessage("SetCommState()"); } else ProcessErrorMessage("BuildCommDCB()"); } else ProcessErrorMessage("GetCommState()"); } else ProcessErrorMessage("SetCommMask()"); } else ProcessErrorMessage("SetCommTimeouts()"); delete [] szPort; delete [] szBa