[lworld] RFR: 8346307: [lworld] Clarify identity vs value in Class, Objects, and document limitations of value objects [v7]

[Chen Liang]

On Wed, 16 Apr 2025 16:51:40 GMT, Roger Riggs <rriggs at openjdk.org> wrote:

>> Add APINote  and javadoc for IdentityException where it will be useful to know that identity or value objects are treated differently. 
>> Simplified WeakHashMap javadoc updates for IdentityException. 
>> Added note to System.identityHashCode to include value objects.
>> Added to class javadoc for IdentityHashMap for value objects.
>
> Roger Riggs has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains nine commits:
> 
>  - Merge branch 'lworld' into 8346307-throws-identityexception
>  - Merge branch 'lworld' into 8346307-throws-identityexception
>  - Merge branch 'lworld' into 8346307-throws-identityexception
>  - Merge
>  - Expand javadoc reference to Reference
>  - Merge remote-tracking branch 'refs/remotes/origin/8346307-throws-identityexception' into 8346307-throws-identityexception
>  - Merge branch 'openjdk:lworld' into 8346307-throws-identityexception
>  - 8346307: [lworld] Document WeakHashMap and other apis that may throw IdentityException
>    Add APINote  and javadoc for IdentityException where it will be useful to know.
>    Simplified WeakHashMap javadoc updates for IdentityException.
>    Added note to System.identityHashCode to include value objects.
>  - 8346307: [lworld] Document WeakHashMap and other apis that may throw IdentityException
>    Add APINote and javadoc for IdentityException where it will be useful to know.
>    Updated Objects.hasIdentity to return true for non-null reference to identity class; else false
>    Added Objects.isValueObject to return true for non-null reference to value class; else false
>    Updated tests for value objects.

PreviewNote isn't merged yet; we can revisit this one once that taglet is available here.

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PR Comment: https://git.openjdk.org/valhalla/pull/1327#issuecomment-2887218953