RFR: 8308088: Improve class check in CollectedHeap::is_oop [v2]

[Albert Mingkun Yang]

On Mon, 15 May 2023 20:15:56 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> See the bug for more details.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 fastdebug, `tier1`
>>  - [x] Linux x86_64 fastdebug, `tier2`
>>  - [x] Linux x86_64 fastdebug, `tier3`
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Avoid touching klass racily (even for v-call)

Marked as reviewed by ayang (Reviewer).

src/hotspot/share/gc/shared/collectedHeap.cpp line 230:

> 228:   }
> 229: 
> 230:   Klass* k = object->klass_raw();

Introducing a local-var doesn't seem needed.

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PR Review: https://git.openjdk.org/jdk/pull/13982#pullrequestreview-1427983254
PR Review Comment: https://git.openjdk.org/jdk/pull/13982#discussion_r1194783083