if (TclInExit()
		&& (pipePtr->flags & PIPE_ASYNC)) {

		/* give it a chance to leave honorably */
		SetEvent(pipePtr->stopWriter);

		if (WaitForSingleObject(pipePtr->writable, 0) == WAIT_TIMEOUT) {
		    return EWOULDBLOCK;
		}

	    } else {

		WaitForSingleObject(pipePtr->writable, INFINITE);

	    }

    timeout = (infoPtr->flags & PIPE_ASYNC) ? 0 : INFINITE;
    if (WaitForSingleObject(infoPtr->writable, 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 error;
    }

    /*
     * Check for a background error on the last write.
     */

	timeout = blocking ? INFINITE : 0;
	if (WaitForSingleObject(infoPtr->readable, timeout) == WAIT_TIMEOUT) {
	    /*
	     * The reader thread is blocked waiting for data and the channel
	     * is in non-blocking mode.
	     */

	    errno = EWOULDBLOCK;
	    return -1;
	}

	/*
	 * At this point, the two threads are synchronized, so it is safe to
	 * access shared state.
	 */