> 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 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 four additional commits since the last revision: - Review comments - Merge branch 'master' of https://github.com/openjdk/jdk into fix/reflect-native-slow - Better comments - 8343377: Performance regression in reflective invocation of native methods ------------- Changes: - all: https://git.openjdk.org/jdk/pull/22169/files - new: https://git.openjdk.org/jdk/pull/22169/files/b314396c..c6d70619 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=22169&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22169&range=00-01 Stats: 109677 lines in 1582 files changed: 54357 ins; 48228 del; 7092 mod Patch: https://git.openjdk.org/jdk/pull/22169.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/22169/head:pull/22169 PR: https://git.openjdk.org/jdk/pull/22169
