Re: [Gc] Weak hash tables and cycles
ivmai at mail.ru
Tue Nov 4 00:29:30 PST 2008
ludo at gnu.org (Ludovic CourtХs) wrote:
> Is it possible to implement a weak-key hash table that can deal with
> cycles using disappearing links?
GC API is at least sufficient to implement Java reference reachability model.
> I'm in particular concerned with the following corner case: K is a key
> in a weak-key hash table, V is its associated value, and V references K.
> This leads to the following object graph, where the dotted arrow denotes
> a disappearing link:
> .---. .---.
> | K |<-----| V |
> `---' `---'
> ^ ^
> : |
> : |
> | weak-key |
> | hash table |
> Neither K nor V can become unreachable in such a case, even if none of
> them is referenced elsewhere.
Well, if You want hash table have strong refs to V then this is the behavior you want (otherwise use weak refs to V).
> Thanks in advance,
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