save-excursion and multi-thread?

[Qiantan Hong]

I tried
(make-thread
 (lambda ()
   (save-excursion (goto-char (point-min)) (sleep-for 1))))
In *scratch*.

It seems that after the thread yields (because of sleep-for)
it doesn’t restore point position, and after 1 second
cursor is reseted to the original position, discarding
any of my movements during this 1 second.

Is this how save-excursion supposed to work?
It’s inconsistent with the behavior of special variable + dynamic bindings,
which works currently under multi-thread.

What’s the supposed way to have “thread-local” movements?

Best,
Qiantan