RFR: JDK-8163581: Heap Parameters in HSDB cannot handle G1CollectedHeap

[Yasumasa Suenaga]

Hi all,

When I chose "Heap Parameters" menu in HSDB, I got following value:
--------------------
Heap Parameters:
unknown subtype of CollectedHeap @ 0x00007f4d4c030510 (0x00000006c6e00000,0x00000007c0000000)
--------------------

I think it should not be "unknown subtype".

This value is shown by sun.jvm.hotspot.gc.shared.CollectedHeap#printOn().
This method is overrided in ParallelScavengeHeap and GenCollectedHeap. However, G1CollectedHeap does not override.

I think G1CollectedHeap should override this method.

I uploaded a webrev for this issue.
Could you review it?

   http://cr.openjdk.java.net/~ysuenaga/JDK-8163581/webrev.00/

I'm jdk 9 committer, but I cannot access JPRT.
So I need a sponsor.


Thanks,

Yasumasa