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