bug#50849: 28.0.50; Proposal for Emacs daemon to signal when being busy

[Eli Zaretskii <eliz@gnu.org>]

> From: Jean Louis <bugs@gnu.support>
> Date: Mon, 27 Sep 2021 17:23:21 +0300
> 
> This is wish for the feature or proposal for Emacs daemon to somehow
> signal to `emacsclient' to be busy.
> 
> We know that if there is no daemon there is environment variable to
> spawn some editor instead, which could be like `emacs -Q' or even `vim'
> 
> If however, the Emacs daemon spawned by `emacs --bg-daemon' is busy for
> example playing video or doing some other process, then `emacsclient'
> cannot know about it and is waiting in background.
> 
> It would be good to provide some kind of a signal that main Emacs
> process is busy so that `emacsclient' can know about it and for example
> spawn the alternative editor in that situation. This feature could be
> then enabled through customization or variable.

The problem in these situations is that AFAIU the daemon doesn't even
know that emacsclient is trying to connect, because it (the daemon)
doesn't process connection requests when it's busy.

You could perhaps do it yourself by deleting the daemon socket when
you play the music.