RFR: 8336267: Method and Constructor signature parsing can be shared on the root object [v2]

[Mandy Chung]

On Wed, 21 Aug 2024 16:03:15 GMT, Chen Liang <liach at openjdk.org> wrote:

>> A straightforward optimization, to share the signature parsing of method, constructor, and field between the root and the copied objects, like how method handle accessors are shared.
>
> Chen Liang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:
> 
>  - Merge branch 'master' of https://github.com/openjdk/jdk into feature/member-sig-share
>  - 8336267: Method and Constructor signature parsing can be shared on the root object

It's okay to extend the root object to share `genericInfo` besides the accessor.  But we need to update the comment to make that clear.


    @Stable
    private ConstructorAccessor constructorAccessor;
    // For sharing of ConstructorAccessors. This branching structure
    // is currently only two levels deep (i.e., one root Constructor
    // and potentially many Constructor objects pointing to it.)
    //
    // If this branching structure would ever contain cycles, deadlocks can
    // occur in annotation code.
    private Constructor<T>      root;


The comment for `root` should be extended to cover the generics repository.   In addition, I suggest to move the declaration of instance variable `genericInfo` closer to the accessor and `root`.

src/java.base/share/classes/java/lang/reflect/Constructor.java line 100:

> 98:                 genericInfo =
> 99:                         ConstructorRepository.make(getSignature(),
> 100:                                 getFactory());

Suggestion:

                genericInfo = ConstructorRepository.make(getSignature(), getFactory());


Nit: This fits well in one line.

src/java.base/share/classes/java/lang/reflect/Field.java line 118:

> 116:                 // create and cache generic info repository
> 117:                 genericInfo = FieldRepository.make(getGenericSignature(),
> 118:                         getFactory());

Suggestion:

                genericInfo = FieldRepository.make(getGenericSignature(), getFactory());

src/java.base/share/classes/java/lang/reflect/Method.java line 122:

> 120:                 // create and cache generic info repository
> 121:                 genericInfo = MethodRepository.make(getGenericSignature(),
> 122:                         getFactory());

Suggestion:

                genericInfo = MethodRepository.make(getGenericSignature(), getFactory());

-------------

PR Review: https://git.openjdk.org/jdk/pull/20179#pullrequestreview-2403193407
PR Review Comment: https://git.openjdk.org/jdk/pull/20179#discussion_r1821607268
PR Review Comment: https://git.openjdk.org/jdk/pull/20179#discussion_r1821608006
PR Review Comment: https://git.openjdk.org/jdk/pull/20179#discussion_r1821608108