在 2020年1月3日 +0800 PM2:06，Eli Zaretskii <eliz@gnu.org>，写道：

How would that help? Until 3 is done, the user doesn't see the
display updated. And if you think 3 doesn't touch any Lisp, then
thats not true, just see how many times you find "Lisp_Object" in,
say, xterm.c.

If 3 can’t be done in separate thread, then we can keep them all as the “UI thread". And let it do as less work as possible by splitting some of work to background workers. Then better user responsiveness is possible.