On Fri, 31 May 2024 16:18:33 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org> wrote:
>> This PR restores a var handle cache in `Utils::makeSegmentViewVarHandle`. >> The cache was moved to `ValueLayouts::varHandle` as part of >> [pull/19251](https://git.openjdk.org/jdk/pull/19251), on the basis that we >> want to optimize the common case like: >> >> >> ValueLayout layout = ... >> layout.varHandle().get(...) >> >> >> And that caching more complex var handles didn't seem to add value, given >> that, for these var handles, the logic in `LayoutPath` needs to adapt the >> returned var handle anyways. >> >> But, `TestAccessModes` revealed a different picture - w/o any cache in >> `Utils` the test end up allocating 8963 var handle instances (instead of >> just 4), in each of the 4 runs the test includes. While this is admittedly a >> stress test, it seems nice to restore the level of sharing we had before >> [pull/19251](https://git.openjdk.org/jdk/pull/19251). > > Maurizio Cimadamore has updated the pull request incrementally with one > additional commit since the last revision: > > Address review comments Thanks for adding the comment. Looks good src/java.base/share/classes/jdk/internal/foreign/Utils.java line 98: > 96: * <p> > 97: * We provide two level of caching of the generated var handles. > First, the var handle associated > 98: * to a {@link ValueLayout#varHandle()} call is cached inside a > stable field of the value layout implementation. Suggestion: * with a {@link ValueLayout#varHandle()} call is cached inside a stable field of the value layout implementation. ------------- Marked as reviewed by jvernee (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/19485#pullrequestreview-2091379947 PR Review Comment: https://git.openjdk.org/jdk/pull/19485#discussion_r1622749916
