Initial commit for dual publishing TopologyRefreshEvent to EventBus

[rkeely]

Publish TopologyRefreshEvent to event bus #2809

Update: 2024-04-07

Only include interface change to get a sense of direction before larger change.

Some reasoning:

1. Creating a new interface called DurationalEvent to capture the traits of event thats not ephemeral or instantaneous.
   I didn't reuse the Event interface because most of events that implements it are instantaneous and I don't want them to
   carry traits that could indicate anything that's related to duration.
2. Adding new methods in EventRecorder to explicitly handle dual publishing (recording with recorder and publishing with event bus or only recording). This seems to be the most straight forward and I am also open to creating a new wrapper class for dual publishing only.
3. Reusing TopologyRefreshEvent as I suspect there are many people subscribing to it from EventBus already. I am also open to create new events class dedicated for the start and end for topology refresh operation.

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[mp911de]

Extending individual events requires duplicating a lot of the functionality within the individual events and it makes these mutable.

I was looking more for an approach where we extend the recording/publishing infrastructure. In particular:

• Add Event getSource() to RecordableEvent and make RecordableEvent extends Event
• Capture the original event in JfrRecordableEvent and rework NoOpEventRecorder to create an event instance
• Long-lived events would be published to EventBus (e.g. EventRecorder.RecordableEvent event = …; later: eventBus.publish(event).
• Adopt JfrEventRecorder.publish(…) to check whether the given event is EventRecorder.RecordableEvent. If so, then we call record(…) on the event instead of jdk.jfr.Event jfrEvent = createEvent(…);
• Retrofit DefaultEventBus to unwrap EventRecorder.RecordableEvent before emitting the event

[rkeely]

Sorry that I deleted my PR branch while doing some rebase.
I have created a new PR #2859. Let's continue the discussion in the new one