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

[Chris Plummer]

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.

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

I don't think EventSetImpl.toString() is involved at all, although if called it can suffer the same ObjectCollectedException, which would be fixed if the issue is addressed in the toString() method of the Event sub-classes instead.

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PR Comment: https://git.openjdk.org/jdk/pull/28666#issuecomment-3614843314