On Fri, 4 Dec 2020 21:22:53 GMT, Chris Plummer <[email protected]> wrote:
>> src/jdk.jdwp.agent/share/native/libjdwp/commonRef.c line 632:
>>
>>> 630: if (weakRef == NULL) {
>>> 631:
>>> EXIT_ERROR(AGENT_ERROR_NULL_POINTER,"NewWeakGlobalRef");
>>> 632: }
>>
>> I'm not so sure I agree that having a fatal error here is the right thing to
>> do. The only other user of `weakenNode()` is
>> `ObjectReference.disableCollection()`. It returns an error to the debugger
>> if `weakenNode()` returns `NULL`. However, I'm not so sure that's a good
>> thing to do here either, since it means the `VM.resume()` will need to fail.
>> Possibly the error should just be ignored, and we live with the ref staying
>> strong.
>
> Another options is to save away the weakref in the node when strengthening.
> This would benefit `ObjectReference.disableCollection()` also, since it would
> no longer need to deal with a potential OOM. However, I'm not so sure it's
> actually worth doing. Trying to keep the debug session alive will having
> allocation errors is probably a fools errand.
I agree a fatal error here seems excessive. Simply maintaining the strong ref
seems reasonable.
-------------
PR: https://git.openjdk.java.net/jdk/pull/1595
