def _start(self, tpart):
        """Start upload and accout for resource consumption."""
        g = gevent.Greenlet(self.uploader, tpart)
        g.link(self._finish)

        # Account for concurrency_burden before starting the greenlet
        # to avoid racing against .join.
        self.concurrency_burden += 1

        self.member_burden += len(tpart)

        g.start()
Start upload and accout for resource consumption.