RFR: 6983726: Reimplement MethodHandleProxies.asInterfaceInstance [v11]

[ExE Boss]

On Mon, 1 May 2023 14:56:27 GMT, Chen Liang <liach at openjdk.org> wrote:

>> As John Rose has pointed out in this issue, the current j.l.r.Proxy based implementation of MethodHandleProxies.asInterface has a few issues:
>> 1. Exposes too much information via Proxy supertype (and WrapperInstance interface)
>> 2. Does not allow future expansion to support SAM[^1] abstract classes
>> 3. Slow (in fact, very slow)
>> 
>> This patch addresses all 3 problems:
>> 1. It implements proxies with one hidden class for each requested interface and replaced WrapperInstance inheritance with a check to the class data. This can avoid unexpected passing of `instanceof`, and avoids the nasty problem of exporting a JDK interface to a dynamic module to ensure access.
>> 2. This patch obtains already generated classes from a ClassValue by the requested interface type; the ClassValue can later be updated to compute implementation generation for abstract classes as well.
>> 3. This patch's generated hidden classes has call performance on par with those of lambda expressions; the creation performance is slightly less than that of LambdaMetafactory: https://jmh.morethan.io/?gist=fcb946d83ee4ac7386901795ca49b224
>> 
>> Additionally, an obsolete `ProxyForMethodHandle` test was removed, for it's no longer applicable. Tests in `jdk/java/lang/invoke` and `jdk/java/lang/reflect` pass.
>> 
>> [^1]: single abstract method
>
> Chen Liang 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 24 additional commits since the last revision:
> 
>  - Renames
>  - Merge branch 'master' into explore/mhp-iface
>  - Consolidate iteration over public methods
>  - Define MH proxy class in a dynamic module
>  - Fix test that depend on WrapperInstance
>  - Require an original lookup in constructor arguments to prevent unintended instantiation
>  - pass interface info via condy,
>    drop explicit ea flags
>    initialize benchmark work variable randomly
>    benchmarks just need 1 fork
>  - Nuke WrapperInstance
>  - Merge branch 'master' into explore/mhp-iface
>  - Whitespace, cleanup, rename benchmarks to be informative
>  - ... and 14 more: https://git.openjdk.org/jdk/compare/10df4e16...f5d0ef0a

src/java.base/share/classes/java/lang/invoke/MethodHandleProxies.java line 225:

> 223:             proxy = lookup.findConstructor(lookup.lookupClass(), methodType(void.class, Lookup.class))
> 224:                           .invoke(lookup);
> 225:             assert proxy.getClass().getModule().isNamed() : proxy.getClass() + " " + proxy.getClass().getModule();

This `assert` should be moved after the `try` statement.

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PR Review Comment: https://git.openjdk.org/jdk/pull/13197#discussion_r1182537580