RFR (L): 8213229: Investigate treating StringTable as weak in young collections

[Kim Barrett]

> On Jan 11, 2019, at 9:51 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
> 
>> On Jan 10, 2019, at 3:46 PM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
>> […]
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8213229
>> Webrev:
>> http://cr.openjdk.java.net/~tschatzl/8213229/webrev.1/
>> Testing:
>> hs-tier1-6, performance checking with our performance suite showed no
>> particular performance differences before/after
>> 
>> Thanks,
>> Thomas
> 
> ------------------------------------------------------------------------------
> 
> I think this change has introduced a memory leak in the StringTable
> OopStorage instance.

Doesn't just leave the OopStorage entries lingering, but also the
associated entries in the table.  However, not really a leak in the
usual sense, I now think.  If the internal table gets rehashed or
needs to grow, the dead entries should be cleaned up.  But having
lingering dead entries may lead earlier rehash or growth than would
otherwise be needed.