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

Aleksey Shipilev aleksey.shipilev at oracle.com
Thu May 9 10:20:46 UTC 2013


On 05/09/2013 02:15 PM, David Holmes wrote:
> On 9/05/2013 7:53 PM, Aleksey Shipilev wrote:
>> On 05/09/2013 01:39 PM, David Holmes wrote:
>>> Well the code change is easy enough to review :)
>>
>> Ha! Bike-shed opportunity: to use fully quailified class name in the
>> annotation, or not. (I'm following the suit for j.u.c.ForkJoinPool and
>> friends).
>>
>>> As to the effects ... no way to judge that: time and testing will tell.
>                                ^for me
>> What exactly do you mean by this?
> 
> Only that I can't validate the utility of this from simple code
> inspection. As time goes by and the code is put to the test we will find
> out if there are any performance issues/surprises and if there still
> lurk any hidden bugs in the @Contended implementation.

Ah, sure, that's why we have benchmarks :) There is a hidden step in
this logic: we've seen how troubling false sharing can be, and so even
if the microbenchmark raises the red flag, it's time to act.

Also, I was watching carefully with this experiment if @Contended breaks
my intuition about things. So far it is does not raise the red flags on
its own.

-Aleksey.




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