On Thu, 13 Aug 2026 12:21:16 GMT, Yasumasa Suenaga <[email protected]> wrote:
>> Value Object has been introduced since JDK 28 (as a preview feature),
>> however it cannot be handled in SA.
>>
>>
>> public value class Test{
>>
>> public static value record Rec(byte recA, byte recB){};
>>
>> byte a;
>>
>> byte b;
>>
>> Rec rec;
>>
>> byte c;
>> }
>>
>>
>> `rec` as `Test$Rec` can be inlined into the instance of `Test`, but it would
>> be shown as "Bad OOP" in "inspect" on SA. SA should show valid values in
>> `rec`.
>>
>> Note that his change would expand flattened object in below in `inspect`
>> CLHSDB command:
>>
>>
>> hsdb> inspect 0xc22419e8
>> instance of Oop for LingeredAppWithValueObject$ValueObj @ 0x00000000c22419e8
>> (size = 16)
>> _mark: 73201086130815105
>> a: 1
>> b: 2
>> rec:
>> recA: 10
>> recB: 20
>> c: 3
>>
>>
>> ---------
>> - [x] I confirm that I make this contribution in accordance with the
>> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai).
>
> Yasumasa Suenaga has updated the pull request incrementally with one
> additional commit since the last revision:
>
> Refactoring
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/oops/Inline.java line 37:
> 35:
> 36: public class Inline extends Instance {
> 37:
I think a comment here is needed that explains that instances of this class can
be used to represent instances of a class that is inline-able (InlineKlass),
both flattened instances and heap instances.
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/oops/Inline.java line 53:
> 51: super(handle, heap);
> 52: this.klass = klass;
> 53: isFlattened = klass != null; // Assumes this instance is
> flattened if klass is passed.
Is klass ever nulll? Seems that it is something that we should assert here, and
just always set isFlattened to true.
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/oops/OopField.java line 68:
> 66: var heap = obj.getHeap();
> 67: return isFlat() ?
> heap.newOop(obj.getHandle().addOffsetToAsOopHandle(getOffset()),
> (InlineKlass)getFieldKlass())
> 68: : heap.newOop(getValueAsOopHandle(obj));
This would be much more readable as an if/else block and if you assigned
`obj.getHandle().addOffsetToAsOopHandle(getOffset())` to a Handle local
variable.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/32310#discussion_r3832187282
PR Review Comment: https://git.openjdk.org/jdk/pull/32310#discussion_r3832168590
PR Review Comment: https://git.openjdk.org/jdk/pull/32310#discussion_r3832139012
