Re: Are there plans for a multi-threaded Emacs?

[Kai Grossjohann]

Miles Bader <address@hidden> writes:

> Consider a simple bit of elisp code:  (setq GLOBAL (cons 'x GLOBAL))
> In a pre-emptively threaded emacs, another thread could run between
> accessing GLOBAL and setting it.  Whoops.

Well, I don't know a lot about threading, but Java, at least, has the
same problem: you need to synchronize access to a variable to prevent
such things from happening.  By default, synchronized access is turned
off.

So if all of what is now in Emacs continues to run in a single thread,
and you just provide a function to create a new thread and run stuff
in that new thread, then it would be the responsibility of the people
creating threads to make sure that they don't step on each other's
toes.

Then the remaining problem is that possibly a lot of functions cannot
be safely used because they access global variables.  But that is just
something that people will have to live with, and maybe it will get
better over time.  I think that it will be good enough at least for
some packages to do part of their work in the background.

What do people think?  Maybe I missed something obvious...

Kai