Re: Emacs design and architecture. How about copy-on-write?

[Eli Zaretskii]

> Date: Wed, 20 Sep 2023 21:50:59 +0300
> Cc: acm@muc.de, incal@dataswamp.org, emacs-devel@gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> Though perhaps redisplay wouldn't be triggered by threads at all - not 
> often, anyway. A thread could send a "request for redisplay" (if it 
> needs to call something like 'redisplay' or 'posn-at-point'), at which 
> point it might get suspended until the "display thread" gets to it. 

Nitpicking: posn-at-point and similar functions are not "redisplay",
they don't redraw any windows.  They just execute some code which is
also used by redisplay.  So there should be no problem calling
posn-at-point regardless of any UI thread and other threads, as long
as access to buffer text is possible.