Re: MPS: dangling markers

[Gerd Möllmann]

Pip Cet <pipcet@protonmail.com> writes:

> On Sunday, June 30th, 2024 at 19:22, Gerd Möllmann <gerd.moellmann@gmail.com> 
> wrote:
>> Thanks! What do youo think about making a patch containing only your
>> weak hash tables, and leaving the BUF_MARKERS alone for now?
>
> I think that's the best way forward. Patch attached.

Could you please send me something from git format-patch? That way I'd
have commit message and your authorship would also be clear. Or even
better, if you have the rights could you please commit to the branch?

(The reason I'm pushing for Helmut is because he doesn't want commit
rights. I'm not the gatekeeper or something of that branch.)

>
>> That way
>> igc could support the existing uses of weak hash tables (I remember one
>> in the CLOS department somehwere), and they would be somewhat tested.
>> Don't remember if we have unit tests for them.
>
> It seems MPS isn't very eager about splatting weak references during
> ordinary automatic GC, FWIW. What I'm observing with
>
> (while t
>   (dotimes (i 10000)
>     (puthash (cons 1 2) (cons 3 4) table))
>   (message "%S" (hash-table-count table))
>   (sit-for 0.1))
>
> is that the hash table starts out at 0, grows quickly, resets to
> count=0 once, then keeps growing and never splats any references after
> that. It's quite possible this is a bug in my code, of course.

Yes, it's not eagerly splatting. Don't know. Which reminds me that I
wanted to look if the AWL pool maybe has some paramter that one could
set, or something else influences that, like the mortality rate of the
generation chain. Or something completely different.