[9] RFR (S): 8148940: java/lang/ref/FinalizeOverride.java can time out due to frequent safepointing

[Zoltán Majó]

Hi,


please review the patch for 8148940:

https://bugs.openjdk.java.net/browse/JDK-8148940

Problem: Since Indify String Concatenation (JDK-8148483) was pushed, the 
execution time of the FinalizeOverride.java test increased by 2-89X.

The increase can be measured both with -Xmixed and -Xcomp and it results 
from a combination of two main factors:
(1) The test spends an increased amount of time in the VM (e.g., because 
an ISC-enabled build can trigger up to 2X more compilations than a 
non-ISC-enabled build);
(2) The test triggers safepointing frequently.

Here are more details on these factors and the exact cause of the failure:
https://bugs.openjdk.java.net/browse/JDK-8148940?focusedCommentId=13904102&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13904102


Possible solutions: Update the test to give more chance to the VM to 
progress. I see two ways of doing that:
Solution #1: Reduce the freqency of triggering GCs
http://cr.openjdk.java.net/~zmajo/8148940/webrev.00/

Solution #2: Remove string operations from finalizers.
http://cr.openjdk.java.net/~zmajo/8148940/webrev.01/

Solution #2 is faster, but it makes more difficult to monitor the 
progress of the test than in the case of Solution #1.

Here are the execution times for both solutions on two platforms:
https://bugs.openjdk.java.net/browse/JDK-8148940?focusedCommentId=13904104&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13904104


Testing: Executed the updated test on the both platforms used for 
evaluation.

Thank you!

Best regards,


Zoltan

<https://bugs.openjdk.java.net/browse/JDK-8150349>