On Fri, 15 Nov 2024 22:17:10 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 This pull request has now been integrated. Changeset: 5958463c Author: Chen Liang <li...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/5958463cadb04560ec85d9af972255bfe6dcc2f2 Stats: 128 lines in 3 files changed: 111 ins; 2 del; 15 mod 8343377: Performance regression in reflective invocation of native methods Reviewed-by: mchung ------------- PR: https://git.openjdk.org/jdk/pull/22169
