private void delimit ()
	{
	    if (state == State.active) {
	        state = State.delimited;
	        return;
	    }

	    if (state == State.pending) {
	        outpipe = null;
	        send_pipe_term_ack (peer);
	        state = State.terminating;
	        return;
	    }

	    //  Delimiter in any other state is invalid.
	    assert (false);
	}