RFR: 6988220: java.lang.ObjectName use of String.intern() causes major performance issues at scale

[Frederic Parain]

No particular reason. But after thinking more about it,
equals() should be a better choice, clearer code, and
the length check in equals() implementation is likely
to help performance of ObjectName's comparisons as
ObjectNames are often long with a common section at the
beginning.

I've updated the webrev:
http://cr.openjdk.java.net/~fparain/6988220/webrev.01/

Thanks,

Fred

On 2/23/12 4:58 PM, Vitaly Davidovich wrote:
> Hi Frederic,
>
> Just curious - why are you checking string equality via compareTo()
> instead of equals()?
>
> Thanks
>
> Sent from my phone
>
> On Feb 23, 2012 10:37 AM, "Frederic Parain" <frederic.parain at oracle.com
> <mailto:frederic.parain at oracle.com>> wrote:
>
>     This a simple fix to solve CR 6988220:
>     http://bugs.sun.com/__bugdatabase/view_bug.do?bug___id=6988220
>     <http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6988220>
>
>     The use of String.intern() in the ObjectName class prevents
>     the class the scale well when more than 20K ObjectNames are
>     managed. The fix simply removes the use of String.intern(),
>     and uses regular String instead. The Object.equals() method
>     is modified too to make a regular String comparison. The
>     complexity of this method now depends on the length of
>     the ObjectName's canonical name, and is not impacted any
>     more by the number of ObjectName instances being handled.
>
>     The Webrev:
>     http://cr.openjdk.java.net/~__fparain/6988220/webrev.00/
>     <http://cr.openjdk.java.net/~fparain/6988220/webrev.00/>
>
>     I've tested this fix with the jdk_lang and jdk_management
>     test suites.
>
>     Thanks,
>
>     Fred
>
>     --
>     Frederic Parain - Oracle
>     Grenoble Engineering Center - France
>     Phone: +33 4 76 18 81 17 <tel:%2B33%204%2076%2018%2081%2017>
>     Email: Frederic.Parain at oracle.com <mailto:Frederic.Parain at oracle.com>
>

-- 
Frederic Parain - Oracle
Grenoble Engineering Center - France
Phone: +33 4 76 18 81 17
Email: Frederic.Parain at oracle.com