Re: understanding weak

[vanicat@debian.org (Rémi Vanicat)]

Alain Frisch <alain@frisch.fr> writes:

> Warren Harris wrote:
>> On Oct 30, 2008, at 11:48 AM, CUOQ Pascal - Pascal.CUOQ@cea.fr wrote:
>>> In short: don't use weak pointers to make caches.
>>
>> Thanks for the advice -- but I thought this was exactly what weak
>> hash tables were intended for.
>
> Although there is some similarity between a weak table and a cache
> ("store values, but feel free to get rid of them"), they are really
> different beasts: a good implementation of a weak table should release
> memory as soon as possible to avoid memory leak; a good implementation
> of a cache should instead keep data as long as possible (until there
> is a good reason to release it, like resource exhaustion).

It's true, but it could be interesting to have a cache pointer/cache
table provided with the garbage collector: it's the GC that know when
there is not enough memory left, and that it should free those cache
pointer to have some.

-- 
Rémi Vanicat