[11u] [JFR] RFR 8225797: OldObjectSample event creates unexpected amount of checkpoint data

[Jaroslav Bachorík]

Hi,

I would like to get this non-trivial JFR related backport reviewed. This
backport is required because OldObjectSample event in the current (JDK 11)
form will cause unlimited growth of the recording thus making this event
unsuitable in production memory leak detection - which is its main purpose.

The backport for 8225797 requires several other changes to be backported as
well. I am listing the changes and the related webrevs here in order to
have all the pieces in one place. The webrevs, unfortunately, are showing
cumulative changes, so please, disregard that information. Each webrev is
generated for that particular commit.

The following tests were run successfully:
- jdk_tier1
- jdk_tier2
- jdk_jfr
- jdk_core

---

Prerequisites:
# 8209850 : Allow NamedThreads to use GlobalCounter critical sections
- applied almost cleanly with only minimal changes to account for slightly
different code structure (patch diff -
http://cr.openjdk.java.net/~jbachorik/8209850/webrev.00/patch.diff)
JIRA .   : https://bugs.openjdk.java.net/browse/JDK-8209850
Webrev : http://cr.openjdk.java.net/~jbachorik/8209850/webrev.00/

# 8209976: Improve iteration over non-JavaThreads
- applied almost cleanly with only minimal changes to account for slightly
different code structure  (patch diff -
http://cr.openjdk.java.net/~jbachorik/8209976/webrev.00/patch.diff)
- JIRA . : https://bugs.openjdk.java.net/browse/JDK-8209976
- Webrev : http://cr.openjdk.java.net/~jbachorik/8209976/webrev.00/
<http://cr.openjdk.java.net/~jbachorik/8209850/webrev.00/>

# 8210024: JFR calls virtual is_Java_thread from ~Thread()
- applied almost cleanly with only minimal changes to account for slightly
different code structure  (patch diff -
http://cr.openjdk.java.net/~jbachorik/8210024/webrev.00/patch.diff)
- JIRA . : https://bugs.openjdk.java.net/browse/JDK-8210024
- Webrev : http://cr.openjdk.java.net/~jbachorik/8210024/webrev.00/

# 8214850: Rename vm_operations.?pp files to vmOperations.?pp files
- applied almost cleanly with only minimal changes to account for slightly
different code structure  (patch diff -
http://cr.openjdk.java.net/~jbachorik/8214850/webrev.00/patch.diff)
- JIRA . : https://bugs.openjdk.java.net/browse/JDK-8214850
- Webrev : http://cr.openjdk.java.net/~jbachorik/8214850/webrev.00/

# 8209802: Garbage collectors should register JFR types themselves to avoid
build errors.
- applied almost cleanly with only minimal changes to account for slightly
different code locations for g1 sources (patch diff -
http://cr.openjdk.java.net/~jbachorik/8209802/webrev.00/patch.diff)
- JIRA . : https://bugs.openjdk.java.net/browse/JDK-8209802
- Webrev : http://cr.openjdk.java.net/~jbachorik/8209802/webrev.00/


Backport:
# 8225797: OldObjectSample event creates unexpected amount of checkpoint
data
- the original patch had to be accommodated to the JDK 11 status of JFR to
minimize the number of prerequisite backports and therefore it is slightly
more complex (patch diff -
http://cr.openjdk.java.net/~jbachorik/8225797/webrev.00/patch.diff)
- JIRA . : https://bugs.openjdk.java.net/browse/JDK-8225797
- Webrev : http://cr.openjdk.java.net/~jbachorik/8225797/webrev.00/


Thanks!

-JB-