[CASSANDRA-11517] o.a.c.utils.UUIDGen could handle contention better

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 3.8
• Component/s: Legacy/Core
• Assignee: Ariel Weisberg
• Reporter: Ariel Weisberg

Authors

Ariel Weisberg

Reviewers

Joel Knighton

• Created: 06/Apr/16 18:57
• Updated: 16/Apr/19 09:30
• Resolved: 09/May/16 00:23

Description

I noticed this profiling a query handler implementation that uses UUIDGen to get handles to track queries for logging purposes.

Under contention threads are being unscheduled instead of spinning until the lock is available. I would have expected intrinsic locks to be able to adapt to this based on profiling information.

Either way it's seems pretty straightforward to rewrite this to use a CAS loop and test that it generally produces unique values.