RFR: 8356255: Add Stable Field Updaters to allow efficient lazy field evaluations [v10]

[David Beaumont]

On Thu, 8 May 2025 13:16:25 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> This sketch shows how "Stable Updaters" can be used to create stable computations of `@Stable` fields. Only one updater is needed per class, similar to `AtomicIntegerFieldUpdater`.
>
> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add composition of functions and MHs

test/jdk/java/lang/StableValue/StableFieldUpdaterExampleTest.java line 120:

> 118: 
> 119:         private static final ToIntFunction<LazyFoo> HASH_UPDATER =
> 120:                 StableFieldUpdater.ofInt(LazyFoo.class, "hash",

Very clean now.

test/jdk/java/lang/StableValue/StableFieldUpdaterExampleTest.java line 183:

> 181:     static
> 182: 
> 183:     public final class MhFoo {

I'm assuming this is explicitly the "behind the scenes" raw version of it in case anyone want's to step off the well-lit path. Hard to comment without seeing any surrounding docs. I don't suppose a link to the docs in which these are given can be added (just to give context for future maintainers)?

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PR Review Comment: https://git.openjdk.org/jdk/pull/25040#discussion_r2079941869
PR Review Comment: https://git.openjdk.org/jdk/pull/25040#discussion_r2079953010