D
don3194
Guest
I've been attempting to compile this guys software that he built to read the data off of a car's computer. The software is called "FreeScan" and his most recent version of it was released just as source code. I downloaded Visual Studio 2017 and after a while I was finally able to run it and build it. I have come acrossed another error "Run-Time Check Failure #3 - The variable 'comstat' is being used without being initialized," I have researched and attempted to find out how to fix it, but since my coding experience is very very limited, I have no idea what to do. I tried bolding and underlining where it says the error is occuring. I'm pretty sure anyone on here already has these, but make sure you have the MFC and ATL stuff downloaded. Also have the VC++ 2017 version 15.9 v14.16 Libs for Spectre (x86 and x64) downloaded and installed, if you try to run this yourself. Unfortunately
you may not beable to reacreate this error because you need the FTDI FT232R serial adapter plugged into usb to use the software.
P.S. Here is the link to maker's page: Freescan - Andy Whittaker
and heres the link to the full sourcecode: AndyWhittaker/FreeScan
they wont let me post links yet
/*
** 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.
** NOTE: Writing is now not on thread *** ARW ***
**
** CREATION DATE 15-09-1997
** LAST MODIFICATION 24-11-1998
**
** AUTHOR Remon Spekreijse
** MODIFIED BY Brian Koh Sze Hsian - Andy Whittaker
**
*/
// (c) 1996-99 Andy Whittaker, Chester, England.
// mail@andywhittaker.com
#include "stdafx.h"
#include "SerialPort.h"
#include <assert.h>
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
//Staic members must be globally defined
CRITICAL_SECTION CSerialPort::m_csCommunicationSync;
OVERLAPPED CSerialPort::m_ov;
int CSerialPort::m_nActualWriteBufferSize = 0;
////////// 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:
ump(CDumpContext& dc) const
{
CObject:ump(dc);
dc << "m_dwError = " << m_dwError;
}
#endif
//
// Constructor
CSerialPort::CSerialPort()
{
m_hComm = NULL;
m_Thread = NULL; // arw: fix for assertion without creating thread.
// initialize overlapped structure members to zero
m_ov.Offset = 0;
m_ov.OffsetHigh = 0;
// create events
m_ov.hEvent = NULL;
m_hShutdownEvent = NULL;
m_bThreadAlive = FALSE;
m_szWriteBuffer = NULL;
m_nWriteBufferSize = 0;
// Recall previous settings from the registry, default Com 1 in case 1st time run.
CWinApp* pApp = AfxGetApp();
m_nPortNr = pApp->GetProfileInt("Communications", "Port", 1);
m_nWriteDelay = pApp->GetProfileInt("Communications", "WriteDelay", 100);
}
// Delete dynamic memory
CSerialPort::~CSerialPort()
{
// Save our settings to the registry
CWinApp* pApp = AfxGetApp();
pApp->WriteProfileInt("Communications", "Port", m_nPortNr);
pApp->WriteProfileInt("Communications", "WriteDelay", m_nWriteDelay);
// resume the thread if it was suspended. Needed to process m_hShutdownEvent!
if(m_Thread != NULL)
{
DWORD dwSuspendCount;
do
{
dwSuspendCount = m_Thread->ResumeThread();
}
while((dwSuspendCount != 0) && (dwSuspendCount != 0xffffffff) );
do
{
SetEvent(m_hShutdownEvent);
}
while (m_bThreadAlive);
TRACE("Thread ended\n");
}
// close handles to avoid memory leaks
CloseHandle(m_ov.hEvent);
CloseHandle(m_hComm);
CloseHandle(m_hShutdownEvent);
m_hComm = NULL;
m_ov.hEvent = NULL;
m_hShutdownEvent = NULL;
if (m_szWriteBuffer != NULL)
delete [] m_szWriteBuffer;
DeleteCriticalSection(&m_csCommunicationSync);
}
IMPLEMENT_DYNAMIC(CSerialPort, CObject)
#ifdef _DEBUG
void CSerialPort:ump(CDumpContext& dc) const
{
CObject:ump(dc);
dc << _T("m_hComm = ") << m_hComm << _T("\n");
}
#endif
//
// Initialize the port. This can be any Com Port.
BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)
UINT portnr, // portnumber (e.g. 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
{
ASSERT(portnr >= 0 && portnr < 15);
if (portnr == NULL)
{// Use the last port setting.
TRACE("CSerialPort::InitPort - Setting COM Port to last value\n");
CWinApp* pApp = AfxGetApp();
m_nPortNr = pApp->GetProfileInt("Communications", "Port", 1);
}
else
m_nPortNr = portnr;
// Call the 2nd override function
return InitPort(pPortOwner,baud,parity,databits,stopbits,dwCommEvents,writebuffersize);
}
// 2nd over-ride - uses the previous Com port number
BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)
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
{
BOOL bResult = FALSE;
ASSERT(pPortOwner != NULL);
CWinApp* pApp = AfxGetApp();
m_nPortNr = pApp->GetProfileInt("Communications", "Port", 1);
TRACE("CSerialPort::InitPort - Com Port %d\n", m_nPortNr);
if (m_nPortNr < 1)
{// This should never happen, however a mistake could have been made in the registry.
TRACE("CSerialPort::InitPort - Com Port cannot be 0");
return FALSE;
}
if (m_nPortNr > 255)
{// This should never happen, however a mistake could have been made in the registry.
TRACE("CSerialPort::InitPort - Com Port cannot be greater than 255");
return FALSE;
}
// 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);
m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!m_ov.hEvent)
AfxThrowSerialException();
if (m_hShutdownEvent != NULL)
ResetEvent(m_hShutdownEvent);
m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!m_hShutdownEvent)
AfxThrowSerialException();
// initialize the event objects
m_hEventArray[0] = m_hShutdownEvent; // highest priority
m_hEventArray[1] = m_ov.hEvent;
// initialize critical section
InitializeCriticalSection(&m_csCommunicationSync);
// set buffersize for writing and save the owner
m_pOwner = pPortOwner;
if (m_szWriteBuffer != NULL) // delete the buffer if it exists
delete [] m_szWriteBuffer;
m_szWriteBuffer = new unsigned char[writebuffersize];
m_nWriteBufferSize = writebuffersize;
m_dwCommEvents = dwCommEvents;
char *szPort = new char[50];
char *szBaud = new char[50];
// now it's 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_s(szPort, 50, "COM%d", m_nPortNr);
sprintf_s(szBaud, 50, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, stopbits);
// 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;
TRACE(_T("Failed to open up the comms port\n"));
AfxThrowSerialException();
return FALSE;
}
// set the timeout values
m_CommTimeouts.ReadIntervalTimeout = 0;
m_CommTimeouts.ReadTotalTimeoutMultiplier = 0;
m_CommTimeouts.ReadTotalTimeoutConstant = 0;
m_CommTimeouts.WriteTotalTimeoutMultiplier = 0;
m_CommTimeouts.WriteTotalTimeoutConstant = 0;
// configure
if (SetCommTimeouts(m_hComm, &m_CommTimeouts))
{
if (SetCommMask(m_hComm, dwCommEvents))
{
if (GetCommState(m_hComm, &m_dcb))
{ // DCB Structure
m_dcb.fRtsControl = RTS_CONTROL_DISABLE; // disable RTS
m_dcb.fOutxCtsFlow = FALSE; // disable CTS
m_dcb.fOutxDsrFlow = FALSE; // disable DSR
m_dcb.fDtrControl = DTR_CONTROL_DISABLE; // disable DTR
m_dcb.fDsrSensitivity = FALSE; // Ignores DSR
m_dcb.fNull = FALSE; // Disable Null Stripping
m_dcb.fTXContinueOnXoff = FALSE; // disable XON/XOFF
m_dcb.fBinary = TRUE; // This is always TRUE in WIN32
m_dcb.fOutX = FALSE; // Disable XOFF checking
m_dcb.fInX = FALSE; // Disable XOFF generation
m_dcb.DCBlength = sizeof(DCB);
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);
EscapeCommFunction(m_hComm, SETDTR); // This is needed for self-powered interfaces
EscapeCommFunction(m_hComm, SETRTS); // This is needed for self-powered interfaces
TRACE("Initialisation for Com Port %d completed.\n",
m_nPortNr);
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;
TRACE("Com Port %d thread is starting.\n", port->m_nPortNr);
// 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-signaled state if there are no bytes
// available to be read, or to a signaled state if there are bytes available.
// If this event handle is set to the non-signaled state, it will be set to
// signaled 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()");
AfxThrowSerialException();
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) 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 (!bResult)
AfxThrowSerialException();
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(2, port->m_hEventArray, FALSE, INFINITE);
Event = Event - WAIT_OBJECT_0; // WaitForMultipleObjects help says to do this.
switch (Event)
{
case 0:
{
// Shutdown event. This is event zero so it will be
// the higest priority and be serviced first.
// Tell the rest of the code that the thread is dying.
port->m_bThreadAlive = FALSE;
break;
} // case 0
case 1: // read event
{
bResult = GetCommMask(port->m_hComm, &CommEvent);
if (!bResult)
AfxThrowSerialException();
// if (CommEvent & EV_CTS)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_CTS_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_RXFLAG)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RXFLAG_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_BREAK)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_BREAK_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_ERR)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_ERR_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_RING)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RING_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
if (CommEvent & EV_RXCHAR)
// Receive character event from port.
ReceiveChar(port, comstat); //THIS IS WHERE THE ERROR IS OCCURING
break;
} // case 1
} // end switch
// we're exiting, break out of loop and end thread
if (port->m_bThreadAlive == FALSE)
break;
} // close forever loop
// when we get here, the thread is about to shutdown and exit.
TRACE("Com Port %d thread about to die.\n", port->m_nPortNr);
return 0;
}
// Start comm watching
BOOL CSerialPort::StartMonitoring()
{
TRACE("Com Port %d starting monitoring.\n", m_nPortNr);
if (!(m_Thread = AfxBeginThread(CommThread, this, THREAD_PRIORITY_NORMAL)))
return FALSE;
// Clear buffer
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
TRACE("Thread %ld started\n", (DWORD)m_Thread->m_nThreadID);
return TRUE;
}
// Restart the comm thread
BOOL CSerialPort::RestartMonitoring()
{
TRACE("Com Port %d re-starting monitoring.\n", m_nPortNr);
// Clear buffer
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
if(m_Thread != NULL)
m_Thread->ResumeThread();
else
StartMonitoring();
return TRUE;
}
// Suspend the comm thread
BOOL CSerialPort::StopMonitoring()
{
if(m_Thread != NULL)
{
TRACE("Com Port %d stopped monitoring.\n", m_nPortNr);
m_Thread->SuspendThread();
}
// Clear buffer
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
return TRUE;
}
//
// If there is a error, give the right message
void CSerialPort:
rocessErrorMessage(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_s(Temp, 200, "WARNING: %s Failed with the following error: \n%s\nPort: %d\n",
(char*)ErrorText, (char*)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;
// Gain ownership of the critical section
EnterCriticalSection(&port->m_csCommunicationSync);
if (bWrite)
{
// Initialise 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 COM Port
port->m_szWriteBuffer, // Pointer to message buffer in calling function
port->m_nActualWriteBufferSize,
&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()");
AfxThrowSerialException();
}
}
}
else
{
LeaveCriticalSection(&port->m_csCommunicationSync);
}
} // end if(bWrite)
// If we have not written all the bytes out, we call GetOverlappedResult(..) to
// wait for the pending writes to happen.
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()");
AfxThrowSerialException();
if (GetLastError() != ERROR_IO_PENDING)
{
TRACE(_T("Failed in call to GetOverlappedResult\n"));
AfxThrowSerialException();
}
}
} // end if (!bWrite)
// Verify that the data size sent equals what we tried to send
if (BytesSent != (DWORD)port->m_nActualWriteBufferSize)
{
TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n",
BytesSent, port->m_nActualWriteBufferSize);
}
}
// Character received. Inform the owner
void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat)
{
BOOL bRead = TRUE;
BOOL bResult = TRUE;
DWORD dwError = 0;
DWORD BytesRead = 0;
DWORD BytesToRead = 1; //modified
unsigned char RXBuff[MAXBYTESTOREAD];//modified
for (;
{
// 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);
BytesToRead = min(MAXBYTESTOREAD, comstat.cbInQue);
LeaveCriticalSection(&port->m_csCommunicationSync);
if (!bResult)
AfxThrowSerialException();
// 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
// solution 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
BytesToRead, // byte to read depends on que
&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()");
AfxThrowSerialException();
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()");
AfxThrowSerialException();
}
} // 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) BytesRead);
} // end forever loop
}
// *************************************************************************************************
// Public Functions
//
// Write a string to the port - This can write even NULL characters
void CSerialPort::WriteToPort(unsigned char* string, int stringlength, BOOL bDelay)
{
assert(m_hComm != 0);
::EnterCriticalSection(&m_csCommunicationSync);
// memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
if (stringlength > MAX_WRITE_BUFFER)
stringlength = MAX_WRITE_BUFFER;
for(int i=0;i<stringlength;i++)
m_szWriteBuffer=string;
m_nActualWriteBufferSize=stringlength;
::LeaveCriticalSection(&m_csCommunicationSync);
if (bDelay)
Sleep(10); // reduces stress on ECU serial port.
WriteChar(this); // Write to port immediately
if (bDelay)
Sleep(m_nWriteDelay); // reduces stress on ECU serial port.
}
// Write a string to the port ** Caution - May be broken
void CSerialPort::WriteToPort(unsigned char* string)
{
assert(m_hComm != 0);
memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
strcpy_s((char *) m_szWriteBuffer, sizeof(m_szWriteBuffer), (char *)string);
m_nActualWriteBufferSize=strlen((char*)m_szWriteBuffer) ? strlen((char*)m_szWriteBuffer) : 1;
WriteChar(this); // Write to port immediately
}
// Returns the device control block
DCB CSerialPort::GetDCB()
{
return m_dcb;
}
// Returns the communication event masks
DWORD CSerialPort::GetCommEvents()
{
return m_dwCommEvents;
}
// Returns the output buffer size
DWORD CSerialPort::GetWriteBufferSize()
{
return m_nWriteBufferSize;
}
// Returns the current port number
UINT CSerialPort::GetPort(void)
{
return m_nPortNr;
}
// Sets the internal com port number
void CSerialPort::SetPort(UINT nPort)
{
CWinApp* pApp = AfxGetApp();
pApp->WriteProfileInt("Communications", "Port", nPort);
TRACE(_T("Comms port number changed\n"));
}
// Returns the minimum number of milliseconds the TX routine will wait before returning
DWORD CSerialPort::GetWriteDelay(void)
{
return m_nWriteDelay;
}
// Sets the minimum number of milliseconds the TX routine will wait before returning
void CSerialPort::SetWriteDelay(DWORD nDelay)
{
m_nWriteDelay = nDelay;
// Write this to the registry
CWinApp* pApp = AfxGetApp();
pApp->WriteProfileInt("Communications", "WriteDelay", m_nWriteDelay);
TRACE(_T("Comms port write delay changed\n"));
}
Continue reading...
you may not beable to reacreate this error because you need the FTDI FT232R serial adapter plugged into usb to use the software.
P.S. Here is the link to maker's page: Freescan - Andy Whittaker
and heres the link to the full sourcecode: AndyWhittaker/FreeScan
they wont let me post links yet
/*
** 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.
** NOTE: Writing is now not on thread *** ARW ***
**
** CREATION DATE 15-09-1997
** LAST MODIFICATION 24-11-1998
**
** AUTHOR Remon Spekreijse
** MODIFIED BY Brian Koh Sze Hsian - Andy Whittaker
**
*/
// (c) 1996-99 Andy Whittaker, Chester, England.
// mail@andywhittaker.com
#include "stdafx.h"
#include "SerialPort.h"
#include <assert.h>
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
//Staic members must be globally defined
CRITICAL_SECTION CSerialPort::m_csCommunicationSync;
OVERLAPPED CSerialPort::m_ov;
int CSerialPort::m_nActualWriteBufferSize = 0;
////////// 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:
ump(CDumpContext& dc) const{
CObject:
ump(dc);dc << "m_dwError = " << m_dwError;
}
#endif
//
// Constructor
CSerialPort::CSerialPort()
{
m_hComm = NULL;
m_Thread = NULL; // arw: fix for assertion without creating thread.
// initialize overlapped structure members to zero
m_ov.Offset = 0;
m_ov.OffsetHigh = 0;
// create events
m_ov.hEvent = NULL;
m_hShutdownEvent = NULL;
m_bThreadAlive = FALSE;
m_szWriteBuffer = NULL;
m_nWriteBufferSize = 0;
// Recall previous settings from the registry, default Com 1 in case 1st time run.
CWinApp* pApp = AfxGetApp();
m_nPortNr = pApp->GetProfileInt("Communications", "Port", 1);
m_nWriteDelay = pApp->GetProfileInt("Communications", "WriteDelay", 100);
}
// Delete dynamic memory
CSerialPort::~CSerialPort()
{
// Save our settings to the registry
CWinApp* pApp = AfxGetApp();
pApp->WriteProfileInt("Communications", "Port", m_nPortNr);
pApp->WriteProfileInt("Communications", "WriteDelay", m_nWriteDelay);
// resume the thread if it was suspended. Needed to process m_hShutdownEvent!
if(m_Thread != NULL)
{
DWORD dwSuspendCount;
do
{
dwSuspendCount = m_Thread->ResumeThread();
}
while((dwSuspendCount != 0) && (dwSuspendCount != 0xffffffff) );
do
{
SetEvent(m_hShutdownEvent);
}
while (m_bThreadAlive);
TRACE("Thread ended\n");
}
// close handles to avoid memory leaks
CloseHandle(m_ov.hEvent);
CloseHandle(m_hComm);
CloseHandle(m_hShutdownEvent);
m_hComm = NULL;
m_ov.hEvent = NULL;
m_hShutdownEvent = NULL;
if (m_szWriteBuffer != NULL)
delete [] m_szWriteBuffer;
DeleteCriticalSection(&m_csCommunicationSync);
}
IMPLEMENT_DYNAMIC(CSerialPort, CObject)
#ifdef _DEBUG
void CSerialPort:
ump(CDumpContext& dc) const{
CObject:
ump(dc);dc << _T("m_hComm = ") << m_hComm << _T("\n");
}
#endif
//
// Initialize the port. This can be any Com Port.
BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)
UINT portnr, // portnumber (e.g. 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
{
ASSERT(portnr >= 0 && portnr < 15);
if (portnr == NULL)
{// Use the last port setting.
TRACE("CSerialPort::InitPort - Setting COM Port to last value\n");
CWinApp* pApp = AfxGetApp();
m_nPortNr = pApp->GetProfileInt("Communications", "Port", 1);
}
else
m_nPortNr = portnr;
// Call the 2nd override function
return InitPort(pPortOwner,baud,parity,databits,stopbits,dwCommEvents,writebuffersize);
}
// 2nd over-ride - uses the previous Com port number
BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)
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
{
BOOL bResult = FALSE;
ASSERT(pPortOwner != NULL);
CWinApp* pApp = AfxGetApp();
m_nPortNr = pApp->GetProfileInt("Communications", "Port", 1);
TRACE("CSerialPort::InitPort - Com Port %d\n", m_nPortNr);
if (m_nPortNr < 1)
{// This should never happen, however a mistake could have been made in the registry.
TRACE("CSerialPort::InitPort - Com Port cannot be 0");
return FALSE;
}
if (m_nPortNr > 255)
{// This should never happen, however a mistake could have been made in the registry.
TRACE("CSerialPort::InitPort - Com Port cannot be greater than 255");
return FALSE;
}
// 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);
m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!m_ov.hEvent)
AfxThrowSerialException();
if (m_hShutdownEvent != NULL)
ResetEvent(m_hShutdownEvent);
m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!m_hShutdownEvent)
AfxThrowSerialException();
// initialize the event objects
m_hEventArray[0] = m_hShutdownEvent; // highest priority
m_hEventArray[1] = m_ov.hEvent;
// initialize critical section
InitializeCriticalSection(&m_csCommunicationSync);
// set buffersize for writing and save the owner
m_pOwner = pPortOwner;
if (m_szWriteBuffer != NULL) // delete the buffer if it exists
delete [] m_szWriteBuffer;
m_szWriteBuffer = new unsigned char[writebuffersize];
m_nWriteBufferSize = writebuffersize;
m_dwCommEvents = dwCommEvents;
char *szPort = new char[50];
char *szBaud = new char[50];
// now it's 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_s(szPort, 50, "COM%d", m_nPortNr);
sprintf_s(szBaud, 50, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, stopbits);
// 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;
TRACE(_T("Failed to open up the comms port\n"));
AfxThrowSerialException();
return FALSE;
}
// set the timeout values
m_CommTimeouts.ReadIntervalTimeout = 0;
m_CommTimeouts.ReadTotalTimeoutMultiplier = 0;
m_CommTimeouts.ReadTotalTimeoutConstant = 0;
m_CommTimeouts.WriteTotalTimeoutMultiplier = 0;
m_CommTimeouts.WriteTotalTimeoutConstant = 0;
// configure
if (SetCommTimeouts(m_hComm, &m_CommTimeouts))
{
if (SetCommMask(m_hComm, dwCommEvents))
{
if (GetCommState(m_hComm, &m_dcb))
{ // DCB Structure
m_dcb.fRtsControl = RTS_CONTROL_DISABLE; // disable RTS
m_dcb.fOutxCtsFlow = FALSE; // disable CTS
m_dcb.fOutxDsrFlow = FALSE; // disable DSR
m_dcb.fDtrControl = DTR_CONTROL_DISABLE; // disable DTR
m_dcb.fDsrSensitivity = FALSE; // Ignores DSR
m_dcb.fNull = FALSE; // Disable Null Stripping
m_dcb.fTXContinueOnXoff = FALSE; // disable XON/XOFF
m_dcb.fBinary = TRUE; // This is always TRUE in WIN32
m_dcb.fOutX = FALSE; // Disable XOFF checking
m_dcb.fInX = FALSE; // Disable XOFF generation
m_dcb.DCBlength = sizeof(DCB);
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);
EscapeCommFunction(m_hComm, SETDTR); // This is needed for self-powered interfaces
EscapeCommFunction(m_hComm, SETRTS); // This is needed for self-powered interfaces
TRACE("Initialisation for Com Port %d completed.\n",
m_nPortNr);
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;
TRACE("Com Port %d thread is starting.\n", port->m_nPortNr);
// 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-signaled state if there are no bytes
// available to be read, or to a signaled state if there are bytes available.
// If this event handle is set to the non-signaled state, it will be set to
// signaled 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()");
AfxThrowSerialException();
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) 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 (!bResult)
AfxThrowSerialException();
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(2, port->m_hEventArray, FALSE, INFINITE);
Event = Event - WAIT_OBJECT_0; // WaitForMultipleObjects help says to do this.
switch (Event)
{
case 0:
{
// Shutdown event. This is event zero so it will be
// the higest priority and be serviced first.
// Tell the rest of the code that the thread is dying.
port->m_bThreadAlive = FALSE;
break;
} // case 0
case 1: // read event
{
bResult = GetCommMask(port->m_hComm, &CommEvent);
if (!bResult)
AfxThrowSerialException();
// if (CommEvent & EV_CTS)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_CTS_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_RXFLAG)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RXFLAG_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_BREAK)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_BREAK_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_ERR)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_ERR_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
// if (CommEvent & EV_RING)
// ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RING_DETECTED,
// (WPARAM) 0, (LPARAM) port->m_nPortNr);
if (CommEvent & EV_RXCHAR)
// Receive character event from port.
ReceiveChar(port, comstat); //THIS IS WHERE THE ERROR IS OCCURING
break;
} // case 1
} // end switch
// we're exiting, break out of loop and end thread
if (port->m_bThreadAlive == FALSE)
break;
} // close forever loop
// when we get here, the thread is about to shutdown and exit.
TRACE("Com Port %d thread about to die.\n", port->m_nPortNr);
return 0;
}
// Start comm watching
BOOL CSerialPort::StartMonitoring()
{
TRACE("Com Port %d starting monitoring.\n", m_nPortNr);
if (!(m_Thread = AfxBeginThread(CommThread, this, THREAD_PRIORITY_NORMAL)))
return FALSE;
// Clear buffer
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
TRACE("Thread %ld started\n", (DWORD)m_Thread->m_nThreadID);
return TRUE;
}
// Restart the comm thread
BOOL CSerialPort::RestartMonitoring()
{
TRACE("Com Port %d re-starting monitoring.\n", m_nPortNr);
// Clear buffer
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
if(m_Thread != NULL)
m_Thread->ResumeThread();
else
StartMonitoring();
return TRUE;
}
// Suspend the comm thread
BOOL CSerialPort::StopMonitoring()
{
if(m_Thread != NULL)
{
TRACE("Com Port %d stopped monitoring.\n", m_nPortNr);
m_Thread->SuspendThread();
}
// Clear buffer
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
return TRUE;
}
//
// If there is a error, give the right message
void CSerialPort:
rocessErrorMessage(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_s(Temp, 200, "WARNING: %s Failed with the following error: \n%s\nPort: %d\n",
(char*)ErrorText, (char*)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;
// Gain ownership of the critical section
EnterCriticalSection(&port->m_csCommunicationSync);
if (bWrite)
{
// Initialise 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 COM Port
port->m_szWriteBuffer, // Pointer to message buffer in calling function
port->m_nActualWriteBufferSize,
&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()");
AfxThrowSerialException();
}
}
}
else
{
LeaveCriticalSection(&port->m_csCommunicationSync);
}
} // end if(bWrite)
// If we have not written all the bytes out, we call GetOverlappedResult(..) to
// wait for the pending writes to happen.
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()");
AfxThrowSerialException();
if (GetLastError() != ERROR_IO_PENDING)
{
TRACE(_T("Failed in call to GetOverlappedResult\n"));
AfxThrowSerialException();
}
}
} // end if (!bWrite)
// Verify that the data size sent equals what we tried to send
if (BytesSent != (DWORD)port->m_nActualWriteBufferSize)
{
TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n",
BytesSent, port->m_nActualWriteBufferSize);
}
}
// Character received. Inform the owner
void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat)
{
BOOL bRead = TRUE;
BOOL bResult = TRUE;
DWORD dwError = 0;
DWORD BytesRead = 0;
DWORD BytesToRead = 1; //modified
unsigned char RXBuff[MAXBYTESTOREAD];//modified
for (;
{
// 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);
BytesToRead = min(MAXBYTESTOREAD, comstat.cbInQue);
LeaveCriticalSection(&port->m_csCommunicationSync);
if (!bResult)
AfxThrowSerialException();
// 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
// solution 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
BytesToRead, // byte to read depends on que
&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()");
AfxThrowSerialException();
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()");
AfxThrowSerialException();
}
} // 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) BytesRead);
} // end forever loop
}
// *************************************************************************************************
// Public Functions
//
// Write a string to the port - This can write even NULL characters
void CSerialPort::WriteToPort(unsigned char* string, int stringlength, BOOL bDelay)
{
assert(m_hComm != 0);
::EnterCriticalSection(&m_csCommunicationSync);
// memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
if (stringlength > MAX_WRITE_BUFFER)
stringlength = MAX_WRITE_BUFFER;
for(int i=0;i<stringlength;i++)
m_szWriteBuffer=string;
m_nActualWriteBufferSize=stringlength;
::LeaveCriticalSection(&m_csCommunicationSync);
if (bDelay)
Sleep(10); // reduces stress on ECU serial port.
WriteChar(this); // Write to port immediately
if (bDelay)
Sleep(m_nWriteDelay); // reduces stress on ECU serial port.
}
// Write a string to the port ** Caution - May be broken
void CSerialPort::WriteToPort(unsigned char* string)
{
assert(m_hComm != 0);
memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
strcpy_s((char *) m_szWriteBuffer, sizeof(m_szWriteBuffer), (char *)string);
m_nActualWriteBufferSize=strlen((char*)m_szWriteBuffer) ? strlen((char*)m_szWriteBuffer) : 1;
WriteChar(this); // Write to port immediately
}
// Returns the device control block
DCB CSerialPort::GetDCB()
{
return m_dcb;
}
// Returns the communication event masks
DWORD CSerialPort::GetCommEvents()
{
return m_dwCommEvents;
}
// Returns the output buffer size
DWORD CSerialPort::GetWriteBufferSize()
{
return m_nWriteBufferSize;
}
// Returns the current port number
UINT CSerialPort::GetPort(void)
{
return m_nPortNr;
}
// Sets the internal com port number
void CSerialPort::SetPort(UINT nPort)
{
CWinApp* pApp = AfxGetApp();
pApp->WriteProfileInt("Communications", "Port", nPort);
TRACE(_T("Comms port number changed\n"));
}
// Returns the minimum number of milliseconds the TX routine will wait before returning
DWORD CSerialPort::GetWriteDelay(void)
{
return m_nWriteDelay;
}
// Sets the minimum number of milliseconds the TX routine will wait before returning
void CSerialPort::SetWriteDelay(DWORD nDelay)
{
m_nWriteDelay = nDelay;
// Write this to the registry
CWinApp* pApp = AfxGetApp();
pApp->WriteProfileInt("Communications", "WriteDelay", m_nWriteDelay);
TRACE(_T("Comms port write delay changed\n"));
}
Continue reading...