On Thu, 10 Sep 2026 13:08:11 GMT, Kieran Farrell <[email protected]> wrote:
>> This patch adds a new jcmd diagnostic command, `VM.show_settings`, to make >> the existing -`XshowSettings` output available from a running VM. The >> command accepts the same sections as`XshowSettings` (all, vm, properties, >> locale, security, system, security:all, security:properties, >> security:providers, security:tls). >> >> HotSpot registers the new diagnostic command, validates the requested >> section, then calls into `sun.launcher.LauncherHelper` to reuse the existing >> show settings formatting and return the result as bytes for the jcmd stream. >> The VM settings path also passes hotspots `InitialHeapSize`, `MaxHeapSize`, >> and Java thread stack size into the Java helper. A new jcmd test covers VM, >> properties, security TLS, and invalid-input output. >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Kieran Farrell has updated the pull request with a new target base due to a > merge or a rebase. The pull request now contains 12 commits: > > - Merge master > - refactor > - split to internal method > - revert mistaken change > - add comment and update print_properties to use CHECK > - remove validation > - extend test coverage and code clean up > - updates > - clean up and add test > - synthax alignmnet > - ... and 2 more: https://git.openjdk.org/jdk/compare/010428f5...f29804f0 I think this looks good. Should mention that ShowSettings.java having the static PrintStream ostream was I suppose fine when this was only ever called by the launcher. Now it's more generally used, we should be clear that the switching of that static while we print the bytes is outdated, though it will generally be OK, we probably don't have concurrent callers. We could keep this under observations and do more modernisation, like passing the stream parameter to the various methods that showSettingsTo() calls, if it ever looks worthwhile. ------------- Marked as reviewed by kevinw (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/31742#pullrequestreview-5168508533
