RFR: 8319548: Unexpected internal name for Filler array klass causes error in VisualVM

[jjscl8888]

On Tue, 19 Dec 2023 10:08:14 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Hi all,
> 
>   please review this change that changes the filler array class name (again) after user feedback.
> 
> In particular, the previous name `Ljdk/internal/vm/FillerArray;` confuses some tools (https://github.com/oracle/visualvm/issues/523). I.e. it's not an array, but still variable sized.
> This change adds the `[` array bracket, and renames the element name to not have `Array` inside to not try to pretend that the element is some other kind of array.
> 
> Testing: tier1-6
> 
> Thanks,
>   Thomas

I observed a phenomenon on our application. When there is no traffic on a certain instance, the number of old generation objects suddenly increases at a certain moment. After dumping the object instances, I found a large number of jdk.internal.vm.FillerArray objects, occupying more than 10G of memory. Have you ever encountered this?
![image](https://github.com/openjdk/jdk/assets/32790117/c515dc81-ce21-4fdd-b132-c1723bbadc73)

-------------

PR Comment: https://git.openjdk.org/jdk/pull/17155#issuecomment-2081389482