RFR: 8299234: JMX Repository.query performance

[Daniel Fuchs]

On Wed, 21 Dec 2022 18:50:52 GMT, Alexey Bakhtin <abakhtin at openjdk.org> wrote:

> Please find a patch to improve JMX Repository.query performance
> 
> Using ObjectName.apply() allows significantly decrease memory usage and the number of GC cycles:
> Before:
> 
> $ java test 1000000 1000000
> Test PASSED in 8943169791 ns.
> GC: G1 Young Generation getCollectionCount()=177 getCollectionTime()=118
> 
> 
> After:
> 
> $ java test 1000000 1000000
> Test PASSED in 4808213917 ns.
> GC: G1 Young Generation getCollectionCount()=88 getCollectionTime()=53
> 
> Private ObjectName.matchDomains() method is also updated to minimize unnecessary memory allocation.
> 
> All javax/management jtreg tests passed successfully.

I see several issues with the proposed changes: ObjectName is not final, so I'm not sure the changes proposed to ObjectName are safe when/if a subclass is supplied. And in addition, because it's not final, you will need to make a defensive copy of the input parameter in Repository::query and do the matching against the copy.

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PR: https://git.openjdk.org/jdk/pull/11758