On Wed, 26 Jun 2024 18:52:40 GMT, Erik Gahlin <egah...@openjdk.org> wrote:
>> This PR changes GenerateJfrFiles.java so that the generated >> `JfrNativeSettings` union does not include JFR structs.`JfrNativeSettings` >> is meant to hold the settings for JFR events, but previously also included >> JFR structs such as MetaspaceSizes, StackFrame, CopyFailed, >> G1EvacuationStatistics, ObjectSpace, VirtualSpace. These are not events, but >> instead are JFR `Type`s, and so do not have settings such as stacktraces or >> thresholds. >> >> The inclusion of JFR structs in `JfrNativeSettings` was problematic because >> it could cause a displacement between event ID and`JfrNativeSettings` array >> index (each index is meant to correspond with a specific event ID). >> >> Testing: >> - jdk/jdk/jfr >> - tier1 > > What drives the settings system is Java where the event name is linked to the > ID, not the enum, e.g. > > jdk.jfr.internal.JVM.setEnabled(eventTypeId, enabled); > > If the type IDs are assigned in the order they appear in metadata.xml, then > there will (or can) be holes. If GenerateJfrFiles.java makes sure native > event types are processed first and then structs, we should be fine. Thank you for the review @egahlin ! ------------- PR Comment: https://git.openjdk.org/jdk/pull/19891#issuecomment-2194648286
