RFR: 8319650: Improve heap dump performance with class metadata caching [v5]

[Aleksey Shipilev]

On Fri, 10 Nov 2023 02:11:54 GMT, Yi Yang <yyang at openjdk.org> wrote:

>> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Drop StackObj
>
> src/hotspot/share/services/heapDumper.cpp line 834:
> 
>> 832:   DumperClassCacheTableEntry* _last_entry;
>> 833: 
>> 834:   void unlink_all(PtrTable* table) {
> 
> This looks bizarre, maybe extract CleanupEntry outside the function.

Thanks. Local functions are explicitly permitted by [Hotspot style guide](https://github.com/openjdk/jdk/blob/master/doc/hotspot-style.md#local-function-objects), and I would argue improve readability here.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/16545#discussion_r1389253569