RFR: 8277216: Examine InstanceKlass::_misc_flags for concurrency issues [v3]

[David Holmes]

On Wed, 15 Dec 2021 20:06:41 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> Recent bug in misc_flags showed that they are not set concurrently and could cause bugs.  Most of the misc_flags are set at classfile parsing time or at a safepoint and never reset.  This change adds an assert that the flag is set once.  See CR for more details.
>> Tested with tier1-3.
>
> Coleen Phillimore has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
> 
>  - Merge branch 'master' into misc
>  - Fix typo.
>  - Move has_resolved_methods to access flags so can be set and tested concurretly.
>  - Move has_resolved_methods to access flags so can be set and tested concurretly.
>  - 8277216: Examine InstanceKlass::_misc_flags for concurrency issues

Or ... assuming these flags are always off by default and only ever turned on, then the set functions should not be taking any argument and should just simply set the given flag bit. Then the asserts would work fine.

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PR: https://git.openjdk.java.net/jdk/pull/6851