Re: Multithread or multiprocess in emacs??

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 16 Apr 2023 22:50:24 +0200
> From: Ergus <spacibba@aol.com>
> 
> Hi:
> 
> Very recently I have seen a code in an elpa package that starts async
> subprocesses; but instead of using make-process the package uses
> make-thread + process-file. This was to reduce the latency and some
> lagging (not evident in my system, but apparently it annoyed the
> package's author).
> 
> So, my question is now: Has anyone measured the overhead created by
> make-process in critical parts of the code like flymake checkers, or
> ispell? and compared with creating new threads?
> 
> If this is somehow significant maybe we may consider adding a helper
> thread or thread-pool for some purposes as now the C11 standard has the
> threads.h header.
> 
> Is there any work already in this direction? How does Elisp handles
> multithreading?

Lisp threads in Emacs don't support parallel processing, whereas async
subprocesses do.  So these two features are not two different
implementations of parallelism.