RFR: 8365400: enhance JFR to emit file and module metadata for class loading

[Larry Cable]

On Thu, 9 Oct 2025 21:04:41 GMT, Larry Cable <duke at openjdk.org> wrote:

> the existing` jdk.classDefine` and `jdk.ClassLoad` events do not include metadata regarding the location/source of the ClassFile.
> 
> The location of the class file for a class defined can be of utility in both debugging and auditing.
> 
> this addition introduces a new `jdk.ClassFileDefine` event which records the class defined and the location (path/url) of the class file that contained the implementation thereof

in previous discussions regarding adding fields to existing JFR (jdk) events I concluded (based on feedback from the JFR team) that this was undesirable hence the new event.

I will investigate the feasibility of adding this metadata to the existing event(s)

knowing where a class originated from, in addition to the knowledge that it has been loaded etc is of particular value in pre-existing auditing and debugging scenarios.

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PR Comment: https://git.openjdk.org/jdk/pull/27738#issuecomment-3389346359