On Mon, 2 Dec 2024 19:45:15 GMT, Chen Liang <li...@openjdk.org> wrote:
>> When core reflection was migrated to be implemented by Method Handles, >> somehow, the method handles are not used for native methods, which are >> generally linkable by method handles. This causes significant performance >> regressions when reflecting native methods, even if their overrides may be >> non-native methods. This is evident in `Object.clone` and `Object.hashCode` >> as shown in the original report. >> >> I believe the blanket restriction previously placed on the native methods >> was because of signature polymorphic methods ([JLS >> 15.12.3](https://docs.oracle.com/javase/specs/jls/se23/html/jls-15.html#jls-15.12.3), >> [JVMS >> 2.9.3](https://docs.oracle.com/javase/specs/jvms/se23/html/jvms-2.html#jvms-2.9.3)) >> for MethodHandle and VarHandle; method handles do not link to the backing >> implementation that throws UOE while core reflection is required to do so. >> I have narrowed the restrictions to be specifically against these methods. >> >> Additionally, I cleaned up another check for invalid varargs flag. >> Together, I clarified the scenarios where native method accessors are used - >> all to bypass restrictions of java.lang.invoke. >> >> Testing: tier 1-5 green > > Chen Liang has updated the pull request incrementally with one additional > commit since the last revision: > > varargs does not matter for effective fix-arity Marked as reviewed by mchung (Reviewer). ------------- PR Review: https://git.openjdk.org/jdk/pull/22169#pullrequestreview-2473784507
