* synchronized with the writable object. */
    int writeBufLen;		/* Size of write buffer. Access is
				 * synchronized with the writable object. */
    int toWrite;		/* Current amount to be written. Access is
				 * synchronized with the writable object. */
    int readFlags;		/* Flags that are shared with the reader
				 * thread. Access is synchronized with the
				 * readable object.  */
    char extraByte;		/* Buffer for extra character consumed by
				 * reader thread. This byte is shared with the
				 * reader thread so access must be
				 * synchronized with the readable object. */
} PipeInfo;

typedef struct {

	const char *p;
	int toCopy;

	/*
	 * Convert the contents from UTF to native encoding
	 */

	if (Tcl_UtfToExternalDStringEx(NULL, NULL, contents, TCL_INDEX_NONE, 0, &dstring, NULL) != TCL_OK) {

	   goto error;
	}
	native = Tcl_DStringValue(&dstring);

	toCopy = Tcl_DStringLength(&dstring);
	for (p = native; toCopy > 0; p++, toCopy--) {
	    if (*p == '\n') {
		length = p - native;

    if (readFile != NULL) {
	/*
	 * Start the background reader thread.
	 */

	infoPtr->readable = CreateEventW(NULL, TRUE, TRUE, NULL);
	infoPtr->readThread = CreateThread(NULL, 256, PipeReaderThread,
	    TclPipeThreadCreateTI(&infoPtr->readTI, infoPtr, infoPtr->readable),

	    0, NULL);
	SetThreadPriority(infoPtr->readThread, THREAD_PRIORITY_HIGHEST);
	infoPtr->validMask |= TCL_READABLE;
    } else {
	infoPtr->readTI = NULL;
	infoPtr->readThread = 0;
    }
    if (writeFile != NULL) {
	/*
	 * Start the background writer thread.
	 */

	infoPtr->writable = CreateEventW(NULL, TRUE, TRUE, NULL);
	infoPtr->writeThread = CreateThread(NULL, 256, PipeWriterThread,
	    TclPipeThreadCreateTI(&infoPtr->writeTI, infoPtr, infoPtr->writable),

	    0, NULL);
	SetThreadPriority(infoPtr->writeThread, THREAD_PRIORITY_HIGHEST);
	infoPtr->validMask |= TCL_WRITABLE;
    } else {
	infoPtr->writeTI = NULL;
	infoPtr->writeThread = 0;
    }

	/*
	 * Clean up the background thread if necessary. Note that this must be
	 * done before we can close the file, since the thread may be blocking
	 * trying to read from the pipe.
	 */

	if (pipePtr->readThread) {

	    TclPipeThreadStop(&pipePtr->readTI, pipePtr->readThread);
	    CloseHandle(pipePtr->readThread);
	    CloseHandle(pipePtr->readable);
	    pipePtr->readThread = NULL;
	}
	if (TclpCloseFile(pipePtr->readFile) != 0) {
	    errorCode = errno;
	}
	pipePtr->validMask &= ~TCL_READABLE;
	pipePtr->readFile = NULL;
    }
    if ((!flags || flags & TCL_CLOSE_WRITE) && (pipePtr->writeFile != NULL)) {
	if (pipePtr->writeThread) {

	    /*
	     * Wait for the  writer thread to finish the  current buffer, then
	     * terminate the thread  and close the handles. If  the channel is
	     * nonblocking or may block during exit, bail out since the worker
	     * thread is not interruptible and we want TIP#398-fast-exit.
	     */
	    if ((pipePtr->flags & PIPE_ASYNC) && inExit) {


		/* give it a chance to leave honorably */
		TclPipeThreadStopSignal(&pipePtr->writeTI, pipePtr->writable);

		if (WaitForSingleObject(pipePtr->writable, 20) == WAIT_TIMEOUT) {
		    return EWOULDBLOCK;
		}

	    } else {

		WaitForSingleObject(pipePtr->writable, inExit ? 5000 : INFINITE);

	    }

	    TclPipeThreadStop(&pipePtr->writeTI, pipePtr->writeThread);

	    CloseHandle(pipePtr->writable);
	    CloseHandle(pipePtr->writeThread);
	    pipePtr->writeThread = NULL;

	}
    }
    return bytesWritten;

  error:
    *errorCode = errno;
    return -1;

}

/*
 *----------------------------------------------------------------------
 *
 * PipeEventProc --
 *

    mask = 0;
    if ((infoPtr->watchMask & TCL_WRITABLE) &&
	    (WaitForSingleObject(infoPtr->writable, 0) != WAIT_TIMEOUT)) {
	mask = TCL_WRITABLE;
    }

    if ((infoPtr->watchMask & TCL_READABLE) && (WaitForRead(infoPtr,0) >= 0)) {
	if (infoPtr->readFlags & PIPE_EOF) {
	    mask = TCL_READABLE;
	} else {
	    mask |= TCL_READABLE;
	}
    }

 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
PipeWatchProc(
    void *instanceData,	/* Pipe state. */
    int mask)			/* What events to watch for, OR-ed combination
				 * of TCL_READABLE, TCL_WRITABLE and
				 * TCL_EXCEPTION. */
{
    PipeInfo **nextPtrPtr, *ptr;
    PipeInfo *infoPtr = (PipeInfo *) instanceData;
    int oldMask = infoPtr->watchMask;

 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
PipeGetHandleProc(
    void *instanceData,	/* The pipe state. */
    int direction,		/* TCL_READABLE or TCL_WRITABLE */
    void **handlePtr)	/* Where to store the handle.  */
{
    PipeInfo *infoPtr = (PipeInfo *) instanceData;
    WinFile *filePtr;

    if (direction == TCL_READABLE && infoPtr->readFile) {
	filePtr = (WinFile*) infoPtr->readFile;
	*handlePtr = (void *)filePtr->handle;

     * Find the process and cut it from the process list.
     */

    Tcl_MutexLock(&pipeMutex);
    prevPtrPtr = &procList;
    for (infoPtr = procList; infoPtr != NULL;
	    prevPtrPtr = &infoPtr->nextPtr, infoPtr = infoPtr->nextPtr) {
	 if (infoPtr->dwProcessId == (Tcl_Size)pid) {
	    *prevPtrPtr = infoPtr->nextPtr;
	    break;
	}
    }
    Tcl_MutexUnlock(&pipeMutex);

    /*