RFR: 8285401: Proxy class initializer should use 3-arg `Class.forName` to avoid unnecessary class initialization [v4]

[Mandy Chung]

On Thu, 26 May 2022 20:52:43 GMT, liach <duke at openjdk.java.net> wrote:

>> Simplify calls `Class.forName(String, boolean, ClassLoader)` instead of `Class.forName(String)`. `make test TEST="jtreg:test/jdk/java/lang/reflect/Proxy"` passes, with the new `LazyInitializationTest` failing the eager initialization check on the baseline and passing with this patch.
>> 
>> On a side note, this might reduce the number of methods that can be encoded in a proxy due to code attribute size restrictions; we probably would address that in another issue, as we never mandated a count of methods that the proxy must be able to implement.
>> 
>> Mandy, would you mind review this?
>
> liach 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 eight additional commits since the last revision:
> 
>  - Merge branch 'master' into proxy-class-forname
>  - Move the try catch block as it doesn't throw checked exceptions
>  - remove unused field
>  - whitespace
>  - Copyright year
>  - typo
>  - 8285401: Proxy class initializer should use 3-arg `Class.forName` to avoid unnecessary class initialization
>  - Test for eager initialization

Thanks for doing this.   It looks okay.   JDK-7194006, having a variant of `Class::forName` that loads the named class with the class loader of the current class, would simplify this.  This can be updated when such an API is defined in the future.

test/jdk/java/lang/reflect/Proxy/LazyInitializationTest.java line 53:

> 51:                 new Class<?>[]{ Intf.class },
> 52:                 (proxy, method, args) -> null);
> 53:         Assert.assertFalse(initialized, "parameter type initialized eagerly");

This expects "parameter type initialized eagerly" to be false.   This may cause confusion to the reader.  Maybe just simply "initialized expected: false" and a comment would help too.  Similarly for line 56.

test/jdk/java/lang/reflect/Proxy/LazyInitializationTest.java line 53:

> 51:                 new Class<?>[]{ Intf.class },
> 52:                 (proxy, method, args) -> null);
> 53:         Assert.assertFalse(initialized, "parameter type initialized eagerly");

This expects "parameter type initialized eagerly" to be false.   This may cause confusion to the reader.  Maybe just simply "initialized expected: false" and a comment would help too.  Similarly for line 56.

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Marked as reviewed by mchung (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/8800