strategy:futures: add runtime assistant support

Add runtime assistant support, which enables to export useful
imformation to users or do judgements if certain conditions
are metched.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
regression: support runtime assistant

1) Support assistant functionality at run time.
2) Change '-a' to support assistant.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>