RFR: 8349860: Make Class.isArray(), Class.isInterface() and Class.isPrimitive() non-native

[Coleen Phillimore]

On Wed, 19 Feb 2025 16:19:22 GMT, Chen Liang <liach at openjdk.org> wrote:

>> src/java.base/share/classes/java/lang/Class.java line 1287:
>> 
>>> 1285:      */
>>> 1286:     public Class<?> getComponentType() {
>>> 1287:         // Only return for array types. Storage may be reused for Class for instance types.
>> 
>> I don't see any changes to componentType related to reuse.  So was this comment and the code below already obsolete?
>
> It was. Before the componentType field was reused for the class initialization monitor int array, and it caused problems with core reflection if a program reflectively accesses this field after a few hundred times. See [JDK-8337622](https://bugs.openjdk.org/browse/JDK-8337622).

Yes, this comment is obsolete.  We used to share the componentType mirror with an internal 'init-lock' but it caused a bug that was fixed.  If it's not an array the componentType is now always null.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/23572#discussion_r1962069719