tclwinserial.c

这是leon3处理器的交叉编译链

/*
 * tclWinSerial.c --
 *
 *  This file implements the Windows-specific serial port functions,
 *  and the "serial" channel driver.
 *
 * Copyright (c) 1999 by Scriptics Corp.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * Serial functionality implemented by [e-mail]
 *
 * RCS: @(#) $Id: tclWinSerial.c,v 1.21 2002/07/19 13:59:10 dkf Exp $
 */

#include "tclWinInt.h"

#include <fcntl.h>
#include <io.h>
#include <sys/stat.h>

/*
 * The following variable is used to tell whether this module has been
 * initialized.
 */

static int initialized = 0;

/*
 * The serialMutex locks around access to the initialized variable, and it is
 * used to protect background threads from being terminated while they are
 * using APIs that hold locks.
 */

TCL_DECLARE_MUTEX(serialMutex)

/*
 * Bit masks used in the flags field of the SerialInfo structure below.
 */

#define SERIAL_PENDING  (1<<0)  /* Message is pending in the queue. */
#define SERIAL_ASYNC    (1<<1)  /* Channel is non-blocking. */

/*
 * Bit masks used in the sharedFlags field of the SerialInfo structure below.
 */

#define SERIAL_EOF      (1<<2)  /* Serial has reached EOF. */
#define SERIAL_ERROR    (1<<4)

/*
 * Default time to block between checking status on the serial port.
 */
#define SERIAL_DEFAULT_BLOCKTIME    10  /* 10 msec */

/*
 * Define Win32 read/write error masks returned by ClearCommError()
 */
#define SERIAL_READ_ERRORS      ( CE_RXOVER | CE_OVERRUN | CE_RXPARITY \
                                | CE_FRAME  | CE_BREAK )
#define SERIAL_WRITE_ERRORS     ( CE_TXFULL | CE_PTO )

/*
 * This structure describes per-instance data for a serial based channel.
 */

typedef struct SerialInfo {
    HANDLE handle;
    struct SerialInfo *nextPtr; /* Pointer to next registered serial. */
    Tcl_Channel channel;        /* Pointer to channel structure. */
    int validMask;              /* OR'ed combination of TCL_READABLE,
                                 * TCL_WRITABLE, or TCL_EXCEPTION: indicates
                                 * which operations are valid on the file. */
    int watchMask;              /* OR'ed combination of TCL_READABLE,
                                 * TCL_WRITABLE, or TCL_EXCEPTION: indicates
                                 * which events should be reported. */
    int flags;                  /* State flags, see above for a list. */
    int readable;               /* flag that the channel is readable */
    int writable;               /* flag that the channel is writable */
    int blockTime;              /* max. blocktime in msec */
    unsigned int lastEventTime;	/* Time in milliseconds since last readable event */
				/* Next readable event only after blockTime */
    DWORD error;                /* pending error code returned by
                                 * ClearCommError() */
    DWORD lastError;            /* last error code, can be fetched with
                                 * fconfigure chan -lasterror */
    DWORD sysBufRead;           /* Win32 system buffer size for read ops, 
                                 * default=4096 */
    DWORD sysBufWrite;          /* Win32 system buffer size for write ops, 
                                 * default=4096 */

    Tcl_ThreadId threadId;      /* Thread to which events should be reported.
                                 * This value is used by the reader/writer
                                 * threads. */
    OVERLAPPED osRead;          /* OVERLAPPED structure for read operations */
    OVERLAPPED osWrite;         /* OVERLAPPED structure for write operations */
    HANDLE writeThread;         /* Handle to writer thread. */
    CRITICAL_SECTION csWrite;   /* Writer thread synchronisation */
    HANDLE evWritable;          /* Manual-reset event to signal when the
                                 * writer thread has finished waiting for
                                 * the current buffer to be written. */
    HANDLE evStartWriter;       /* Auto-reset event used by the main thread to
                                 * signal when the writer thread should attempt
                                 * to write to the serial. */
    DWORD writeError;           /* An error caused by the last background
                                 * write.  Set to 0 if no error has been
                                 * detected.  This word is shared with the
                                 * writer thread so access must be
                                 * synchronized with the evWritable object.
                                 */
    char *writeBuf;             /* Current background output buffer.
                                 * Access is synchronized with the evWritable
                                 * object. */
    int writeBufLen;            /* Size of write buffer.  Access is
                                 * synchronized with the evWritable
                                 * object. */
    int toWrite;                /* Current amount to be written.  Access is
                                 * synchronized with the evWritable object. */
    int writeQueue;             /* Number of bytes pending in output queue.
                                 * Offset to DCB.cbInQue.
                                 * Used to query [fconfigure -queue] */
} SerialInfo;

typedef struct ThreadSpecificData {
    /*
     * The following pointer refers to the head of the list of serials
     * that are being watched for file events.
     */

    SerialInfo *firstSerialPtr;
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;

/*
 * The following structure is what is added to the Tcl event queue when
 * serial events are generated.
 */

typedef struct SerialEvent {
    Tcl_Event header;       /* Information that is standard for
                             * all events. */
    SerialInfo *infoPtr;    /* Pointer to serial info structure.  Note
                             * that we still have to verify that the
                             * serial exists before dereferencing this
                             * pointer. */
} SerialEvent;

/*
 * We don't use timeouts.
 */

static COMMTIMEOUTS no_timeout = {
    0,               /* ReadIntervalTimeout */
    0,               /* ReadTotalTimeoutMultiplier */
    0,               /* ReadTotalTimeoutConstant */
    0,               /* WriteTotalTimeoutMultiplier */
    0,               /* WriteTotalTimeoutConstant */
};

/*
 * Declarations for functions used only in this file.
 */

static int      SerialBlockProc(ClientData instanceData, int mode);
static void     SerialCheckProc(ClientData clientData, int flags);
static int      SerialCloseProc(ClientData instanceData,
                Tcl_Interp *interp);
static int      SerialEventProc(Tcl_Event *evPtr, int flags);
static void     SerialExitHandler(ClientData clientData);
static int      SerialGetHandleProc(ClientData instanceData,
                int direction, ClientData *handlePtr);
static ThreadSpecificData *SerialInit(void);
static int      SerialInputProc(ClientData instanceData, char *buf,
                int toRead, int *errorCode);
static int      SerialOutputProc(ClientData instanceData, CONST char *buf,
                int toWrite, int *errorCode);
static void     SerialSetupProc(ClientData clientData, int flags);
static void     SerialWatchProc(ClientData instanceData, int mask);
static void     ProcExitHandler(ClientData clientData);
static int       SerialGetOptionProc _ANSI_ARGS_((ClientData instanceData,
                Tcl_Interp *interp, CONST char *optionName,
                Tcl_DString *dsPtr));
static int       SerialSetOptionProc _ANSI_ARGS_((ClientData instanceData,
                Tcl_Interp *interp, CONST char *optionName,
                CONST char *value));
static DWORD WINAPI     SerialWriterThread(LPVOID arg);

/*
 * This structure describes the channel type structure for command serial
 * based IO.
 */

static Tcl_ChannelType serialChannelType = {
    "serial",                   /* Type name. */
    TCL_CHANNEL_VERSION_2,      /* v2 channel */
    SerialCloseProc,            /* Close proc. */
    SerialInputProc,            /* Input proc. */
    SerialOutputProc,           /* Output proc. */
    NULL,                       /* Seek proc. */
    SerialSetOptionProc,        /* Set option proc. */
    SerialGetOptionProc,        /* Get option proc. */
    SerialWatchProc,            /* Set up notifier to watch the channel. */
    SerialGetHandleProc,        /* Get an OS handle from channel. */
    NULL,                       /* close2proc. */
    SerialBlockProc,            /* Set blocking or non-blocking mode.*/
    NULL,                       /* flush proc. */
    NULL,                       /* handler proc. */
};

/*
 *----------------------------------------------------------------------
 *
 * SerialInit --
 *
 *  This function initializes the static variables for this file.
 *
 * Results:
 *  None.
 *
 * Side effects:
 *  Creates a new event source.
 *
 *----------------------------------------------------------------------
 */

static ThreadSpecificData *
SerialInit()
{
    ThreadSpecificData *tsdPtr;

    /*
     * Check the initialized flag first, then check it again in the mutex.
     * This is a speed enhancement.
     */

    if (!initialized) {
        Tcl_MutexLock(&serialMutex);
        if (!initialized) {
            initialized = 1;
            Tcl_CreateExitHandler(ProcExitHandler, NULL);
        }
        Tcl_MutexUnlock(&serialMutex);
    }

    tsdPtr = (ThreadSpecificData *)TclThreadDataKeyGet(&dataKey);
    if (tsdPtr == NULL) {
        tsdPtr = TCL_TSD_INIT(&dataKey);
        tsdPtr->firstSerialPtr = NULL;
        Tcl_CreateEventSource(SerialSetupProc, SerialCheckProc, NULL);
        Tcl_CreateThreadExitHandler(SerialExitHandler, NULL);
    }
    return tsdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * SerialExitHandler --
 *
 *  This function is called to cleanup the serial module before
 *  Tcl is unloaded.
 *
 * Results:
 *  None.
 *
 * Side effects:
 *  Removes the serial event source.
 *
 *----------------------------------------------------------------------
 */

static void
SerialExitHandler(
    ClientData clientData)  /* Old window proc */
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    SerialInfo *infoPtr;

    /*
     * Clear all eventually pending output.
     * Otherwise Tcl's exit could totally block,
     * because it performs a blocking flush on all open channels.
     * Note that serial write operations may be blocked due to handshake.
     */
    for (infoPtr = tsdPtr->firstSerialPtr; infoPtr != NULL;
            infoPtr = infoPtr->nextPtr) {
        PurgeComm(infoPtr->handle, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR 
            | PURGE_RXCLEAR);

    }
    Tcl_DeleteEventSource(SerialSetupProc, SerialCheckProc, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * ProcExitHandler --
 *
 *  This function is called to cleanup the process list before
 *  Tcl is unloaded.
 *
 * Results:
 *  None.
 *
 * Side effects:
 *  Resets the process list.
 *
 *----------------------------------------------------------------------
 */

static void
ProcExitHandler(
    ClientData clientData)  /* Old window proc */
{
    Tcl_MutexLock(&serialMutex);
    initialized = 0;
    Tcl_MutexUnlock(&serialMutex);
}

/*
 *----------------------------------------------------------------------
 *
 * SerialBlockTime --
 *
 *  Wrapper to set Tcl's block time in msec
 *
 * Results:
 *  None.
 *----------------------------------------------------------------------
 */

static void
SerialBlockTime(
    int msec)          /* milli-seconds */
{
    Tcl_Time blockTime;

    blockTime.sec  =  msec / 1000;
    blockTime.usec = (msec % 1000) * 1000;
    Tcl_SetMaxBlockTime(&blockTime);
}
/*
 *----------------------------------------------------------------------
 *
 * SerialGetMilliseconds --
 *
 *  Get current time in milliseconds,
 *  Don't care about integer overruns
 *
 * Results:
 *  None.
 *----------------------------------------------------------------------
 */

static unsigned int
SerialGetMilliseconds(
    void)
{
    Tcl_Time time;

    TclpGetTime(&time);

    return (time.sec * 1000 + time.usec / 1000);
}
/*
 *----------------------------------------------------------------------
 *
 * SerialSetupProc --
 *
 *  This procedure is invoked before Tcl_DoOneEvent blocks waiting
 *  for an event.
 *
 * Results:
 *  None.
 *
 * Side effects:
 *  Adjusts the block time if needed.
 *
 *----------------------------------------------------------------------
 */

void
SerialSetupProc(
    ClientData data,    /* Not used. */
    int flags)          /* Event flags as passed to Tcl_DoOneEvent. */
{
    SerialInfo *infoPtr;
    int block = 1;
    int msec = INT_MAX; /* min. found block time */
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

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

    /*
     * Look to see if any events handlers installed. If they are, do not block.
     */

    for (infoPtr = tsdPtr->firstSerialPtr; infoPtr != NULL;
            infoPtr = infoPtr->nextPtr) {

        if (infoPtr->watchMask & TCL_WRITABLE) {
            if (WaitForSingleObject(infoPtr->evWritable, 0) != WAIT_TIMEOUT) {
                block = 0;
                msec = min( msec, infoPtr->blockTime );
            }
        }
        if( infoPtr->watchMask & TCL_READABLE ) {
            block = 0;
            msec = min( msec, infoPtr->blockTime );