RFR (XS) CR 8014233: java.lang.Thread should be @Contended

Doug Lea dl at cs.oswego.edu
Thu May 9 10:38:30 UTC 2013

On 05/09/13 05:39, David Holmes wrote:
> Hi Aleksey
> Well the code change is easy enough to review :)
> As to the effects ... no way to judge that: time and testing will tell.

For some initial sanity-check testing, I just built lambda with
the added @Contended annotation on Thread and ran a few
of our jsr166 performance tests involving classes that
somehow frequently touch Thread fields. It seems to be
a strictly positive change. Not a dramatic one on average, but
the main benefit is avoiding occasional really terrible performance
due to the GC colocating all Thread objects, or locating them
near busy ThreadLocals etc.


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