8291733: Remove JFR events that expose hashtable

[GoeLin]

I backport this for parity with 17.0.18-oracle.

Resolved EventNames.java, probably clean anyways.

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Issue

• JDK-8291733: Remove JFR events that expose hashtable (Enhancement - P4)

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[openjdk]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 00: Full (11513439)

[egahlin]

Sorry about this. Oracle plans to back out the removal of these events, as the enhancement backport was a mistake. Instead, the events will be disabled in default.jfc, which is much less intrusive but still prevents excessive overhead in the out-of-the-box configuration.

In other words, only make this change:

diff --git a/src/jdk.jfr/share/conf/jfr/default.jfc b/src/jdk.jfr/share/conf/jfr/default.jfc
index 6faba56991c..6b5659a24b0 100644
--- a/src/jdk.jfr/share/conf/jfr/default.jfc
+++ b/src/jdk.jfr/share/conf/jfr/default.jfc
@@ -38,17 +38,17 @@
     </event>
 
     <event name="jdk.PlaceholderTableStatistics">
-      <setting name="enabled">true</setting>
+      <setting name="enabled">false</setting>
       <setting name="period">10 s</setting>
     </event>
 
     <event name="jdk.LoaderConstraintsTableStatistics">
-      <setting name="enabled">true</setting>
+      <setting name="enabled">false</setting>
       <setting name="period">10 s</setting>
     </event>
 
     <event name="jdk.ProtectionDomainCacheTableStatistics">
-      <setting name="enabled">true</setting>
+      <setting name="enabled">false</setting>
       <setting name="period">10 s</setting>
     </event>
 

[GoeLin]

Thanks for the patch above!