RFR: 8294960: Convert java.base/java.lang.invoke package to use the Classfile API to generate lambdas and method handles [v25]

[Claes Redestad]

On Wed, 19 Jun 2024 09:08:35 GMT, Adam Sotona <asotona at openjdk.org> wrote:

>> java.base java.lang.invoke package heavily uses ASM to generate lambdas and method handles.
>> 
>> This patch converts ASM calls to Classfile API.
>> 
>> This PR is continuation of https://github.com/openjdk/jdk/pull/12945
>> 
>> Any comments and suggestions are welcome.
>> 
>> Please review.
>> 
>> Thank you,
>> Adam
>
> Adam Sotona has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - removed empty line
>  - problem-listed runtime/ClassInitErrors/TestStackOverflowDuringInit.java

No objections as long as there's an understanding that we'll need to work on some of the startup/warmup regressions this will cause.

We have preliminary data on a subset of benchmarks which suggests it's a combination of loading more classes and spreading the work across a larger set of methods, which means we need to warm and JIT more methods to reach peak performance. ASM is a smaller library with a more minimalist approach, so it loads faster and gets up and running a bit faster. We'll probably need to file regressions as they are detected for tracking purposes, but I expect we'll continue chipping away at and improving the classfile API in the months to come.

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Marked as reviewed by redestad (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17108#pullrequestreview-2127764187