RFR: 8055416: Several vm/gc/heap/summary "After GC" events emitted for the same GC ID

[Stefan Karlsson]

Hi all,

Please review this patch to make sure that the "heap summary after gc" 
events  are only sent once.

http://cr.openjdk.java.net/~stefank/8055416/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8055416

This was found in one of our closed JFR tests. From the bug report:
---
For client VM and G1 GC several vm/gc/heap/summary events with property 
when='After GC' could be emitted for the same GC ID.
At the same time there will be only one 'Before GC' vm/gc/heap/summary 
event for the same GC ID.
---

thanks,
StefanK