Subject: bug#66993: [PATCH] project.el: avoid asking user about project-list-file lock

From: Dmitry Gutov <[email-masked]>
Date: Wed, 8 Nov 2023 15:56:11 +0200

On 08/11/2023 15:50, Eli Zaretskii wrote:
> Why do you need an error when you can use file-locked-p to check up
> front that the file is locked?

IIUC the problem comes due to concurrent writes from concurrent writes 
from parallel Emacs instances.

Simply checking whether the file is locked before writing, without 
trying to obtain the lock, is unlikely to be a reliable solution 
(another instance might lock it right after we checked).

Anyway, these writes must be very fast and relatively infrequent. So I'm 
surprised that this has came up, personally.