On Mon, 16 Sep 2024 12:01:26 GMT, Per Minborg <pminb...@openjdk.org> wrote:
>> This PR suggests introducing an internal class in `java.base` to simplify >> the use of some `MethodHandles.Lookup` operations. >> >> While the utility of the methods might appear to be limited in classes with >> many static `VarHandle`/`MethodHandle` variables, it should be noted that >> the class files become smaller and simpler. Here are some examples: >> >> | Class File | Base [Bytes] | Patch >> [Byte] | >> | --------------------------------| ------------- | ------------ | >> | FutureTask.class | 10,255 | >> 10,123 | >> | AtomicBoolean.class | 5,364 | >> 5,134 | >> |AtomicMarkableReference.class | 3,890 | 3,660 | >> >>  >> >> The new `MethodHandlesInternal.class` file is of size 1,952 bytes. >> >> In total for `java.base` we have: >> >> | Build map "jdk" | Size [Bytes] | >> | ---------------| ------------- | >> | Base | 5,906,457 | >> | Patch | 5,905,487 | >> | Delta | 940| >> >> For 60 billion instances, this represents > 50 TB. >> >> Tried and passed tier1-3 > > Per Minborg 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 five additional > commits since the last revision: > > - Move to new package and add overload > - Merge branch 'master' into internal-mh-util > - Rename and reformat > - Fix copyright headers > - Introduce MethodHandlesInternal It is possible to create a project-specific utility method that can unwrap several methods like this: @FunctionalInterface public interface LookupFunction<R> { R apply(MethodHandles.Lookup lookup, Class<?> refc, String name, MethodType type) throws NoSuchMethodException, IllegalAccessException; } public static <R> R unwrap(LookupFunction<R> lookupFunction, MethodHandles.Lookup lookup, Class<?> refc, String name, MethodType type) { try { return lookupFunction.apply(lookup, refc, name, type); } catch (ReflectiveOperationException e) { throw new InternalError(e); } } static final MethodHandle MH_SCALE = MethodHandlesUtil.unwrap(MethodHandles.Lookup::findVirtual, MethodHandles.lookup(), MemoryLayout.class, "scale", MethodType.methodType(long.class, long.class, long.class)); ------------- PR Comment: https://git.openjdk.org/jdk/pull/20972#issuecomment-2355690263
