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

[Eli Zaretskii]

> Date: Sat, 23 Sep 2023 15:53:11 +0300
> Cc: acm@muc.de, incal@dataswamp.org, emacs-devel@gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> On 23/09/2023 14:23, Eli Zaretskii wrote:
> > As a trivial example, any function that modifies a file-visiting
> > buffer could prompt the user if the file was meanwhile modified on
> > disk.  This prompt is completely out of control of any Lisp program
> > which does something that modifies buffer text.  How do we handle
> > these cases? their name is a legion.
> 
> Any function that prompts the user is not supposed to be fast. So it 
> might as well acquire any number of global locks to do that.

That's not my point.  My point is that if we say that changes to adapt
existing code to threads are acceptable, we will have to make those
changes all over our infrastructure, otherwise programs written for
threads will not ready for threads 100%.