The JVM is preventing Ehcache from accessing the subgraph

[aghasemi]

Hello,

I get this message when trying the sizeOf method:

The JVM is preventing Ehcache from accessing the subgraph beneath 'private final byte[] java.lang.String.value' - cache sizes may be underestimated as a result

, followed by a stack trace but then actually an estimated number. I suspect this has to do something with newer Java versions. I use Java 21.

Is there any possibility to avoid this issue?

Thanks for the work, by the way.

P.S. Another question: Does sizeOf work on a "class" that contains static Objects?

[henri-tremblay]

Static fields do not matter since they are static. So they are not considered as part of the cache. Only objects can be added to a cache.

sizeof, when doing deep reflection, is limited to what it can do reflection on. I suspect that in this case, you need some --add-open on java.base/java.lang (not sure of the syntax, I'm going by heart here)

[aghasemi]

Thank you for the information.

Yes, the subgraph issues go away by adding proper add-opens arguments, but eventually I get this exception:

java.lang.UnsupportedOperationException: can't get field offset on a record class: private final java.security.CodeSource java.security.SecureClassLoader$CodeSourceKey.cs

, which is actually not caught and prevents the computation (Java 21). Is there a workaround for this as well?

[Rattlyy]

, which is actually not caught and prevents the computation (Java 21). Is there a workaround for this as well?
JOL has the same issue and they fixed it in this way: https://bugs.openjdk.org/browse/CODETOOLS-7902931