RFR: 8274944: AppCDS dump causes SEGV in VM thread while adjusting lambda proxy class info [v3]

[David Holmes]

On Mon, 25 Oct 2021 20:48:37 GMT, Calvin Cheung <ccheung at openjdk.org> wrote:

>> During dumping of CDS archive, the `ArchiveBuilder::gather_klass_and_symbol` set the address of an object to null if the
>> object cannot be archived. Since the lambda proxy class in this scenario contains an old version (major version < 50) of
>> interface which has been linked, the class won't be archived and its address will be set to null. The `SystemDictionaryShared::adjust_lambda_proxy_class_dictionary` is called after 
>> `ArchiveBuilder::gather_klass_and_symbol` and thus encountered the null pointer.
>> 
>> A fix is to add a function `SystemDictionaryShared::cleanup_lambda_proxy_class_dictionary` to cleanup the
>> `_dumptime_lambda_proxy_class_dictionary` at the beginning of the CDS dumping operation.
>> 
>> The proposed fix passed tiers 1 - 4 testing (including the new tests).
>
> Calvin Cheung has updated the pull request incrementally with one additional commit since the last revision:
> 
>   revert the change of calling SystemDictionaryShared::start_dumping() in metaspaceShared.cpp

Seems fine.

Thanks,
David

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Marked as reviewed by dholmes (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/6070