RFR: 8349088: De-virtualize Codeblob and nmethod [v10]

[Axel Boldt-Christmas]

On Sat, 15 Feb 2025 06:34:56 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> Remove virtual methods from CodeBlob and nmethod to simplify saving/restoring in Leyden AOT cache. It avoids the need to patch hidden VPTR pointer to class's virtual table.
>> 
>> Added C++ static asserts to make sure no virtual methods are added in a future.
>> 
>> Fixed/cleaned SA code which process CodeBlob and its subclasses. Use `CodeBlob::_kind` field value to determine the type of blob.
>> 
>> Tested tier1-5, hs-tier6-rt (for JFR testing), stress, xcomp
>
> Vladimir Kozlov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove commented lines left by mistake

Not looked at the SA changes.

lgtm.

src/hotspot/share/code/codeBlob.hpp line 308:

> 306: 
> 307:   class Vptr : public CodeBlob::Vptr {
> 308:   };

Was this needed for some compiler? Or is it to be more explicit about the type hierarchy?

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Marked as reviewed by aboldtch (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23533#pullrequestreview-2620128040
PR Review Comment: https://git.openjdk.org/jdk/pull/23533#discussion_r1957678232