[OAK-9634] CacheLIRS: test failure with ARM processor (Apple M1)

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.42.0, 1.22.11
• Labels: arm
• Assignee: Thomas Mueller
• Reporter: Thomas Mueller
• Created: 03/Dec/21 16:11
• Updated: 09/Jun/22 15:27
• Resolved: 06/Dec/21 07:15

Description

In a ARM machine (MacBook with M1 chip) I get a "somewhat" reproducible failure as follows:

[ERROR] Tests run: 3, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 2.304 s <<< FAILURE! - in org.apache.jackrabbit.oak.cache.ConcurrentTest
[ERROR] testRandomOperations(org.apache.jackrabbit.oak.cache.ConcurrentTest)  Time elapsed: 1.068 s  <<< ERROR!
java.lang.NullPointerException
	at org.apache.jackrabbit.oak.cache.CacheLIRS$Segment.find(CacheLIRS.java:1323)
	at org.apache.jackrabbit.oak.cache.CacheLIRS.peek(CacheLIRS.java:263)
	at org.apache.jackrabbit.oak.cache.CacheLIRS.entrySet(CacheLIRS.java:545)
	at org.apache.jackrabbit.oak.cache.CacheLIRS$1.entrySet(CacheLIRS.java:1731)
	at org.apache.jackrabbit.oak.cache.ConcurrentTest$3.run(ConcurrentTest.java:210)

If I slightly change the code (e.g. add try-catch in the find method), then it no longer fails. I think the problem is the different memory model of ARM chips, and so e.key is assigned a bit after the entry is added to the array.

Making the key final resolved the issue for me.

Issue Links

• is cloned by: OAK-9796 oak-segment-remote and oak-segment-aws Redis tests fail with ARM processor (Apple M1)
• links to: GitHub Pull Request #432