TclFile writeFile,		/* If non-null, gives the file for writing. */
    TclFile errorFile,		/* If non-null, gives the file where errors
				 * can be read. */
    int numPids,		/* The number of pids in the pid array. */
    Tcl_Pid *pidPtr)		/* An array of process identifiers. */
{
    char channelName[16 + TCL_INTEGER_SPACE];

    PipeInfo *infoPtr = ckalloc(sizeof(PipeInfo));

    PipeInit();

    infoPtr->watchMask = 0;
    infoPtr->flags = 0;
    infoPtr->readFlags = 0;

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

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

	     * 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) && TclInExit()) {

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

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

	    } else {

static DWORD WINAPI
PipeWriterThread(
    LPVOID arg)
{
    TclPipeThreadInfo *pipeTI = (TclPipeThreadInfo *)arg;
    PipeInfo *infoPtr = NULL; /* access info only after success init/wait */
    HANDLE handle = NULL;
    DWORD count, toWrite;
    char *buf;
    int done = 0;

    while (!done) {
	/*
	 * Wait for the main thread to signal before attempting to write.
	 */
	if (!TclPipeThreadWaitForSignal(&pipeTI)) {
	    /* exit */



	    break;
	}

	if (!infoPtr) {
	    infoPtr = (PipeInfo *)pipeTI->clientData;
	    handle = ((WinFile *) infoPtr->writeFile)->handle;

	}

	buf = infoPtr->writeBuf;
	toWrite = infoPtr->toWrite;

	/*
	 * Loop until all of the bytes are written or an error occurs.

	}

	/*
	 * Signal the main thread by signalling the writable event and then
	 * waking up the notifier thread.
	 */

	SetEvent(infoPtr->writable);

	/*
	 * Alert the foreground thread. Note that we need to treat this like a
	 * critical section so the foreground thread does not terminate this
	 * thread while we are holding a mutex in the notifier code.
	 */

 *
 *----------------------------------------------------------------------
 */

TclPipeThreadInfo *
TclPipeThreadCreateTI(
    TclPipeThreadInfo **pipeTIPtr,
    ClientData clientData,
    HANDLE wakeEvent)
{
    TclPipeThreadInfo *pipeTI;
#ifndef _PTI_USE_CKALLOC
    pipeTI = malloc(sizeof(TclPipeThreadInfo));
#else
    pipeTI = ckalloc(sizeof(TclPipeThreadInfo));
#endif
    pipeTI->evControl = CreateEvent(NULL, FALSE, FALSE, NULL);
    pipeTI->state = PTI_STATE_IDLE;
    pipeTI->clientData = clientData;
    pipeTI->evWakeUp = wakeEvent;
    return (*pipeTIPtr = pipeTI);
}

/*
 *----------------------------------------------------------------------
 *
 * TclPipeThreadWaitForSignal --

int
TclPipeThreadWaitForSignal(
    TclPipeThreadInfo **pipeTIPtr)
{
    TclPipeThreadInfo *pipeTI = *pipeTIPtr;
    LONG state;
    DWORD waitResult;
    HANDLE wakeEvent;

    if (!pipeTI) {
	return 0;
    }

    wakeEvent = pipeTI->evWakeUp;
    /*
     * Wait for the main thread to signal before attempting to do the work.
     */

    /* reset work state of thread (idle/waiting) */
    if ((state = InterlockedCompareExchange(&pipeTI->state,
	    PTI_STATE_IDLE, PTI_STATE_WORK)) & (PTI_STATE_STOP|PTI_STATE_END)) {

    /* signaled to work */
    return 1;   

end:
    /* end of work, check the owner of the TI structure */
    if (state != PTI_STATE_STOP) {
	*pipeTIPtr = NULL;
    } else {
    	pipeTI->evWakeUp = NULL;
    }
    if (wakeEvent) {
    	SetEvent(wakeEvent);
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *

 *	1 if signaled (or pipe-thread is down), 0 if pipe thread still working.
 *
 *----------------------------------------------------------------------
 */

int
TclPipeThreadStopSignal(
    TclPipeThreadInfo **pipeTIPtr, HANDLE wakeEvent)
{
    TclPipeThreadInfo *pipeTI = *pipeTIPtr;
    HANDLE evControl;
    int state;

    if (!pipeTI) {
	return 1;
    }
    evControl = pipeTI->evControl;
    pipeTI->evWakeUp = wakeEvent;
    switch (
	(state = InterlockedCompareExchange(&pipeTI->state,
	    PTI_STATE_STOP, PTI_STATE_IDLE))
    ) {

	case PTI_STATE_IDLE:

    int state;

    if (!pipeTI) {
	return;
    }
    pipeTI = *pipeTIPtr;
    evControl = pipeTI->evControl;
    pipeTI->evWakeUp = NULL;
    /*
     * Try to sane stop the pipe worker, corresponding its current state
     */
    switch (
	(state = InterlockedCompareExchange(&pipeTI->state,
	    PTI_STATE_STOP, PTI_STATE_IDLE))
    ) {

    if (!pipeTI) {
	return;
    }
    *pipeTIPtr = NULL;
    if ((state = InterlockedExchange(&pipeTI->state,
	    PTI_STATE_DOWN)) == PTI_STATE_STOP) {
	CloseHandle(pipeTI->evControl);
	if (pipeTI->evWakeUp) {
	    SetEvent(pipeTI->evWakeUp);
	}
    #ifndef _PTI_USE_CKALLOC
	free(pipeTI);
    #else
	ckfree(pipeTI);
	/* be sure all subsystems used are finalized */
	Tcl_FinalizeThread();
    #endif