RFR: 8301992: Embed SymbolTable CHT node [v3]

[Ioi Lam]

On Wed, 15 Feb 2023 23:51:26 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> Yes, it seemed dubious if we ever freed the entry from the symbol arena, so I think it's ok.  It would only free the Symbol if it was the last one allocated and there was a race when inserting the same permanent symbol in the table.
>> 
>> You're right there would be a bug if we tried to free a CHeap allocated symbol from the arena if the refcount became permanent.  I'm not sure what would happen in that case.
>
> Oh but if it overflows the refcount to become permanent, the permanence is sticky. We won't free it, so it's not a bug.

>From the comment above this code, it seems we do free permanent symbols, but only when the current thread lost when competing to insert a symbol for the boot loader. So the old code is correct, and the new code would have a leak.

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PR: https://git.openjdk.org/jdk/pull/12562