Re: elisp test-and-set?

[Eli Zaretskii]

> From: Stephen Leake <address@hidden>
> Date: Fri, 25 May 2018 16:00:04 -0500
> 
> In ada-mode, I'm using a parser running in an external process to
> compute faces and indentation.
> 
> Since faces are computed by font-lock, which runs on a timer in the
> background, it can try to run when indent is running in the foreground.

Do you have evidence of this?  Emacs is single-threaded, so only one
Lisp function can run at any given time.  I'm guessing you saw
something that led you to above conclusion, but I think the conclusion
is at least inaccurate if not incorrect.  So please tell more detail
about what you see, and probably about the implementation of that
parser.  E.g., are you running the parser from font-lock, or are you
running it from some other hook?