Re: [PATCH] Marking weak alist vectors

[Han-Wen Nienhuys]

Ludovic Courtès wrote:
> > Does your patch solve the problem that cyclical structures (values that 
> > point back to keys) should also be GC-ed?
>
>
> I guess you're talking about cyclical structures in doubly-weak alist
> vectors.  If so, it apparently does since if both WEAK_VALUES and
> WEAK_KEYS are false in both functions, then neither the key nor the
> value will ever be marked by those functions.

Actually, I was talking about tables with only weak keys, but strong values.

> 1.  The tests in `weaks.test' are broken in several ways, not only
>     because "we have no way of knowing for certain that the object is
>     really dead" as stated there.

You can detect whether objects died; just generate a lot of them, and 
see what happens to the stats the output of (gc-live-object-stats) after 
a few GCs.

> 3.  Given the level of non-determinism I've been able to observe, I'm
>     afraid leaks are causing us difficulties.  For instance, while
>     testing weakly-key alist vectors "by hand" in a REPL, it occurred to
>     me that the weak-key pair would reliably die, *unless* the hash
>     table was written (I mean using `write'):

Curious; why does this happen?

> That's the whole point of the test: object properties are used because
> they involve weak hash tables.

In that case, I'm missing the point completely; why do you need this 
functionality?

--
 Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen