Re: Concurrency via isolated process/thread

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: yantar92@posteo.net,  emacs-devel@gnu.org
> Date: Sun, 09 Jul 2023 17:25:21 +0800
> 
> > Emacs doesn't have a UI thread, as you know.
> 
> Emacs's equivalent is the main thread, which is the only thread that can
> safely call redisplay.

Which makes it impossible to display indications that are unrelated to
buffer text displayed in some window.  We use the "normal"
buffer/window/frame/redisplay machinery for showing such indications
(a good example is progress report), but the downsides of this are:

  . we cannot show the indications asynchronously, although they have
    absolutely no relation to any other buffer or window, and
  . they look badly when compared to modern GUI facilities