'Called when a new worker is started.
:param socket sock: The listen socket for the worker just started.
:param _unused: The socket\'s opaque_data yielded by new_worker_socks().
:param int pid: The new worker process\' PID'

def register_worker_start(self, sock, _unused, pid):

    self.logger.notice(('Started    child    %s' % pid))
    self.children.append(pid)
