RFR: 8373102: com/sun/jdi/MethodInvokeWithTraceOnTest.java can fail with ObjectCollectedException when run with a small heap

[Alex Menkov]

On Thu, 4 Dec 2025 21:00:41 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

> With JDI tracing enabled, an attempt to trace an event when using SUSPEND_NONE can result in an ObjectCollectedException because the thread is still running and objects that are part of the trace can be collected already. In this case were were dealing with trying to print the thread name for a VirtualThreadEndEvent, and the virtual thread has already exited and been gc'd.
> 
> Tested by running test case before change (verified failure) and after change (50 runs without a failure). Will also run tier1 and tier5 svc just to be sure.

> > I think better solution would be to catch `ObjectCollectedException` in `EventSetImpl.toString` implementations (and print al least event name).
> > But it might not be worth the effort, so it's up to you
> 
> I think your suggesting to implement it in all of the Event subclasses implemented as inner classes of EventSetImpl, right?

It would be more complete solution, but even fixing only `EventSetImpl.toString` (for each event, printing event name (or class name of the event) + "<got ObjectCollectedException>" on the exception ) should be good enough

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PR Comment: https://git.openjdk.org/jdk/pull/28666#issuecomment-3614827467