Review request for JDK-8011095 PropertyHashMap.rehash() does not grow enough

A. Sundararajan sundararajan.athijegannathan at oracle.com
Sun Mar 31 22:11:23 PDT 2013


hmm.. For constructors, we start with an empty map and keep growing it 
with every "this.foo" assignment, right? If no history, how constructors 
generated objects will share maps? Or am I missing something?

-Sundar

On Sunday 31 March 2013 04:46 PM, Jim Laskey (Oracle) wrote:
> I well tested.  Beginning to believe that history in general may not be worth it, since it does take up considerable space and is somewhat compensated by predefined maps at set call sites.
>
>
> On 2013-03-31, at 5:08 AM, Marcus Lagergren <marcus.lagergren at oracle.com> wrote:
>
>> What Hannes said. Also looks good. Pls do some performance verification.
>> /M
>>
>> On Mar 30, 2013, at 4:40 PM, Hannes Wallnoefer <hannes.wallnoefer at oracle.com> wrote:
>>
>>> Looks good to me. The one thing I'm not sure about is the implications of not caching history for empty properties. On the one hand it seems plausible to avoid creating a huge property map tree where nothing is ever garbage collected, but on the hand everything starting at the empty properties map will not use history while still recording it, which is a wasted effort.
>>>
>>> I think we should do some testing with octane to see what operations actually use history or not with this scheme.
>>>
>>> Hannes
>>>
>>>
>>> Am 2013-03-30 14:53, schrieb Jim Laskey (Oracle):
>>>> Please review http://cr.openjdk.java.net/~jlaskey/8011095/webrev.00/
>>>>



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