Re: elisp test-and-set?

[Noam Postavsky]

On 25 May 2018 at 17:00, Stephen Leake <address@hidden> wrote:

> 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.

Only if the foreground indent function calls `accept-process-output',
`sit-for', or something like that.

> In other contexts I'd use a "test and set" instruction for this; read
> the flag and set it true in one uninterruptible action. I don't see
> anything like that in elisp, and searching in the elisp manual for
> "mutual" and "exclusion" is no help.

There is `(elisp) Mutexes' (as of Emacs 26), but even with threads
enabled, only a single Lisp thread runs at one time, so there's not
really a need for it at the moment.