tclwinserial.c

这是leon3处理器的交叉编译链

    int bufSize,                /* How much space is available
                                 * in the buffer? */
    int *errorCode)             /* Where to store error code. */
{
    SerialInfo *infoPtr = (SerialInfo *) instanceData;
    DWORD bytesRead = 0;
    COMSTAT cStat;

    *errorCode = 0;

    /*
     * Check if there is a CommError pending from SerialCheckProc
     */
    if( infoPtr->error & SERIAL_READ_ERRORS ){
        goto commError;
    }

    /*
     * Look for characters already pending in windows queue.
     * This is the mainly restored good old code from Tcl8.0
     */

    if( ClearCommError( infoPtr->handle, &infoPtr->error, &cStat ) ) {
        /*
         * Check for errors here, but not in the evSetup/Check procedures
         */

        if( infoPtr->error & SERIAL_READ_ERRORS ) {
            goto commError;
        }
        if( infoPtr->flags & SERIAL_ASYNC ) {
            /*
             * NON_BLOCKING mode:
             * Avoid blocking by reading more bytes than available
             * in input buffer
             */

            if( cStat.cbInQue > 0 ) {
                if( (DWORD) bufSize > cStat.cbInQue ) {
                    bufSize = cStat.cbInQue;
                }
            } else {
                errno = *errorCode = EAGAIN;
                return -1;
            }
        } else {
            /*
             * BLOCKING mode:
             * Tcl trys to read a full buffer of 4 kBytes here
             */

            if( cStat.cbInQue > 0 ) {
                if( (DWORD) bufSize > cStat.cbInQue ) {
                    bufSize = cStat.cbInQue;
                }
            } else {
                bufSize = 1;
            }
        }
    }

    if( bufSize == 0 ) {
        return bytesRead = 0;
    }

    /*
    *  Perform blocking read. Doesn't block in non-blocking mode, 
    *  because we checked the number of available bytes.
    */
    if (blockingRead(infoPtr, (LPVOID) buf, (DWORD) bufSize, &bytesRead,
            &infoPtr->osRead) == FALSE) {
        goto error;
    }
    return bytesRead;

error:
    TclWinConvertError(GetLastError());
    *errorCode = errno;
    return -1;

commError:
    infoPtr->lastError = infoPtr->error;  /* save last error code */
    infoPtr->error = 0;                   /* reset error code */
    *errorCode = EIO;                     /* to return read-error only once */
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * SerialOutputProc --
 *
 *  Writes the given output on the IO channel. Returns count of how
 *  many characters were actually written, and an error indication.
 *
 * Results:
 *  A count of how many characters were written is returned and an
 *  error indication is returned in an output argument.
 *
 * Side effects:
 *  Writes output on the actual channel.
 *
 *----------------------------------------------------------------------
 */

static int
SerialOutputProc(
    ClientData instanceData,    /* Serial state. */
    CONST char *buf,            /* The data buffer. */
    int toWrite,                /* How many bytes to write? */
    int *errorCode)             /* Where to store error code. */
{
    SerialInfo *infoPtr = (SerialInfo *) instanceData;
    int bytesWritten, timeout;

    *errorCode = 0;

    /*
     * At EXIT Tcl trys to flush all open channels in blocking mode.
     * We avoid blocking output after ExitProc or CloseHandler(chan)
     * has been called by checking the corrresponding variables.
     */
    if( ! initialized || TclInExit() ) {
        return toWrite;
    }

    /*
     * Check if there is a CommError pending from SerialCheckProc
     */
    if( infoPtr->error & SERIAL_WRITE_ERRORS ){
        infoPtr->lastError = infoPtr->error;  /* save last error code */
        infoPtr->error = 0;                   /* reset error code */
        errno = EIO;            
        goto error;
    }

    timeout = (infoPtr->flags & SERIAL_ASYNC) ? 0 : INFINITE;
    if (WaitForSingleObject(infoPtr->evWritable, timeout) == WAIT_TIMEOUT) {
        /*
         * The writer thread is blocked waiting for a write to complete
         * and the channel is in non-blocking mode.
         */

        errno = EWOULDBLOCK;
        goto error1;
    }
    /*
     * Check for a background error on the last write.
     */

    if (infoPtr->writeError) {
        TclWinConvertError(infoPtr->writeError);
        infoPtr->writeError = 0;
        goto error1;
    }

    /*
     * Remember the number of bytes in output queue
     */
    EnterCriticalSection(&infoPtr->csWrite);
    infoPtr->writeQueue += toWrite;
    LeaveCriticalSection(&infoPtr->csWrite);

    if (infoPtr->flags & SERIAL_ASYNC) {
        /*
         * The serial is non-blocking, so copy the data into the output
         * buffer and restart the writer thread.
         */

        if (toWrite > infoPtr->writeBufLen) {
            /*
             * Reallocate the buffer to be large enough to hold the data.
             */

            if (infoPtr->writeBuf) {
                ckfree(infoPtr->writeBuf);
            }
            infoPtr->writeBufLen = toWrite;
            infoPtr->writeBuf = ckalloc(toWrite);
        }
        memcpy(infoPtr->writeBuf, buf, toWrite);
        infoPtr->toWrite = toWrite;
        ResetEvent(infoPtr->evWritable);
        SetEvent(infoPtr->evStartWriter);
        bytesWritten = toWrite;

    } else {
        /*
        * In the blocking case, just try to write the buffer directly.
        * This avoids an unnecessary copy.
        */
        if (! blockingWrite(infoPtr, (LPVOID) buf, (DWORD) toWrite,
                &bytesWritten, &infoPtr->osWrite) ) {
            goto writeError;
        }
        if (bytesWritten != toWrite) {
            /* Write timeout */
            infoPtr->lastError |= CE_PTO;
            errno = EIO;
            goto error;
        }
    }

    return bytesWritten;

writeError:
    TclWinConvertError(GetLastError());

error:
    /* 
     * Reset the output queue counter on error during blocking output 
     */
/*
    EnterCriticalSection(&infoPtr->csWrite);
    infoPtr->writeQueue = 0;
    LeaveCriticalSection(&infoPtr->csWrite);
*/
  error1: 
    *errorCode = errno;
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * SerialEventProc --
 *
 *  This function is invoked by Tcl_ServiceEvent when a file event
 *  reaches the front of the event queue.  This procedure invokes
 *  Tcl_NotifyChannel on the serial.
 *
 * Results:
 *  Returns 1 if the event was handled, meaning it should be removed
 *  from the queue.  Returns 0 if the event was not handled, meaning
 *  it should stay on the queue.  The only time the event isn't
 *  handled is if the TCL_FILE_EVENTS flag bit isn't set.
 *
 * Side effects:
 *  Whatever the notifier callback does.
 *
 *----------------------------------------------------------------------
 */

static int
SerialEventProc(
    Tcl_Event *evPtr,   /* Event to service. */
    int flags)          /* Flags that indicate what events to
                         * handle, such as TCL_FILE_EVENTS. */
{
    SerialEvent *serialEvPtr = (SerialEvent *)evPtr;
    SerialInfo *infoPtr;
    int mask;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!(flags & TCL_FILE_EVENTS)) {
        return 0;
    }

    /*
     * Search through the list of watched serials for the one whose handle
     * matches the event.  We do this rather than simply dereferencing
     * the handle in the event so that serials can be deleted while the
     * event is in the queue.
     */

    for (infoPtr = tsdPtr->firstSerialPtr; infoPtr != NULL;
            infoPtr = infoPtr->nextPtr) {
        if (serialEvPtr->infoPtr == infoPtr) {
            infoPtr->flags &= ~(SERIAL_PENDING);
            break;
        }
    }

    /*
     * Remove stale events.
     */

    if (!infoPtr) {
        return 1;
    }

    /*
     * Check to see if the serial is readable.  Note
     * that we can't tell if a serial is writable, so we always report it
     * as being writable unless we have detected EOF.
     */

    mask = 0;
    if( infoPtr->watchMask & TCL_WRITABLE ) {
        if( infoPtr->writable ) {
            mask |= TCL_WRITABLE;
            infoPtr->writable = 0;
        }
    }

    if( infoPtr->watchMask & TCL_READABLE ) {
        if( infoPtr->readable ) {
            mask |= TCL_READABLE;
            infoPtr->readable = 0;
        }
    }

    /*
     * Inform the channel of the events.
     */

    Tcl_NotifyChannel(infoPtr->channel, infoPtr->watchMask & mask);
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * SerialWatchProc --
 *
 *  Called by the notifier to set up to watch for events on this
 *  channel.
 *
 * Results:
 *  None.
 *
 * Side effects:
 *  None.
 *
 *----------------------------------------------------------------------
 */

static void
SerialWatchProc(
    ClientData instanceData,     /* Serial state. */
    int mask)                    /* What events to watch for, OR-ed
                                  * combination of TCL_READABLE,
                                  * TCL_WRITABLE and TCL_EXCEPTION. */
{
    SerialInfo **nextPtrPtr, *ptr;
    SerialInfo *infoPtr = (SerialInfo *) instanceData;
    int oldMask = infoPtr->watchMask;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    /*
     * Since the file is always ready for events, we set the block time
     * so we will poll.
     */

    infoPtr->watchMask = mask & infoPtr->validMask;
    if (infoPtr->watchMask) {
        if (!oldMask) {
            infoPtr->nextPtr = tsdPtr->firstSerialPtr;
            tsdPtr->firstSerialPtr = infoPtr;
        }
        SerialBlockTime(infoPtr->blockTime);
    } else {
        if (oldMask) {
            /*
             * Remove the serial port from the list of watched serial ports.
             */

            for (nextPtrPtr = &(tsdPtr->firstSerialPtr), ptr = *nextPtrPtr;
                    ptr != NULL;
                    nextPtrPtr = &ptr->nextPtr, ptr = *nextPtrPtr) {
                if (infoPtr == ptr) {
                    *nextPtrPtr = ptr->nextPtr;
                    break;
                }
            }
        }
    }
}

/*
 *----------------------------------------------------------------------
 *
 * SerialGetHandleProc --
 *
 *  Called from Tcl_GetChannelHandle to retrieve OS handles from
 *  inside a command serial port based channel.
 *
 * Results:
 *  Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if
 *  there is no handle for the specified direction.
 *
 * Side effects:
 *  None.
 *
 *----------------------------------------------------------------------
 */

static int
SerialGetHandleProc(
    ClientData instanceData,    /* The serial state. */
    int direction,              /* TCL_READABLE or TCL_WRITABLE */
    ClientData *handlePtr)      /* Where to store the handle.  */
{
    SerialInfo *infoPtr = (SerialInfo *) instanceData;

    *handlePtr = (ClientData) infoPtr->handle;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * SerialWriterThread --
 *
 *      This function runs in a separate thread and writes data
 *      onto a serial.
 *
 * Results:
 *      Always returns 0.
 *
 * Side effects:
 *      Signals the main thread when an output operation is completed.
 *      May cause the main thread to wake up by posting a message.