Re: Non file buffers and default-directory

[Eli Zaretskii <eliz@gnu.org>]

> From: Emanuel Berg <incal@dataswamp.org>
> Date: Tue, 25 Apr 2023 19:54:56 +0200
> 
> Eli Zaretskii wrote:
> 
> > Thanks. This is promising, but it also means that some
> > changes are needed in smtpmail-send-it to avoid the bad and
> > the ugly part. (And further discussions should probably move
> > to emacs-devel.)
> >
> > Thank you for doing this, I think it will be a very
> > important feature when it becomes available.
> 
> How do you do a defun with any/arbitrary Elisp code and call
> it without Emacs becoming nonresponsive executing the code, no
> matter how simple/complex, for the duration of the time the
> code is executing?

You use Lisp threads.  If done correctly, Emacs will respond to user
input while another thread is waiting for a sub-process (in this case,
network connection to the SMTP server) to produce output.  See the
node "Threads" in the ELisp Reference manual.

> Note that if this period is prolonged because of
> "non-nonresponsive" interactive activity outside of this code,
> such a prolongment, slim or big, is okay in this sense
> (prevent nonresponsiveness), as that is another issue.

Parse error.