On Fri, 16 Oct 2026 15:13:08 GMT, Yunbo Zhang <[email protected]> wrote:
> Please review this performance fix. > > For reference arrays, `ArrayType.newInstance()` searches all loaded classes > for the component class, which can be slow when many classes are loaded. > > **Fix:** > > Search the array's class loader first, with the global lookup as a fallback. > Hidden classes continue to use the global lookup. > > **Testing:** > > - Added hidden-class and `int[][]` coverage to `NewInstanceTest`. > - `com/sun/jdi`: 191 passed (1 excluded by the existing ProblemList) > - `vmTestbase/nsk/jdi`: 1143 passed (including 2 skips for a transport > unsupported) > - `vmTestbase/nsk/jdwp`: 114 passed (1 excluded by the existing ProblemList) > - `vmTestbase/nsk/jdb`: 68 passed > - Local JDI `Object[]` measurement with 70,000 additional classes: **17.27 > ms/call -> 0.156 ms/call**. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). This pull request has now been integrated. Changeset: e37ebb04 Author: Yunbo Zhang <[email protected]> Committer: Serguei Spitsyn <[email protected]> URL: https://git.openjdk.org/jdk/commit/e37ebb048d738b8432bdc97392c7b0634ecc4faf Stats: 122 lines in 2 files changed: 73 ins; 29 del; 20 mod 8343851: Slow new array creation in case of many classes loaded Reviewed-by: cjplummer, sspitsyn ------------- PR: https://git.openjdk.org/jdk/pull/33414
