RFR [8011215] optimization of CopyOnWriteArrayList.addIfAbsent()

[Louis Wasserman]

I would be deeply suspicious of benchmarks that naive, especially for
benchmarks like this that involve lots of allocation -- you're most likely
benchmarking the GC, not the actual operation.


On Tue, Apr 2, 2013 at 3:33 PM, Ivan Gerasimov <ivan.gerasimov at oracle.com>wrote:

>
> On 03.04.2013 1:17, Martin Buchholz wrote:
>
>> Have you benchmarked the case where the element is never present?
>>
> That's the only case I've tested.
> If the element were in the array, my code would obviously win.
>
>
>  (with the usual caveats about micro-benchmarking - perhaps use google
>> caliper?)
>>
> The tests I wrote are quite simple - they just run a code snippet for
> several hundreds of times.
> I've just sent and archive with the tests in reply to the other message in
> the thread.
>
>
>
>> On Tue, Apr 2, 2013 at 2:11 PM, Ivan Gerasimov <ivan.gerasimov at oracle.com<mailto:
>> ivan.gerasimov at oracle.**com <ivan.gerasimov at oracle.com>>> wrote:
>>
>>
>>     I've done a little testing on my side.
>>     I used Integer as an underlying type and set length of the array
>>     to the values from 1 to 100.
>>     My code shows a little performance gain - approximately 9%.
>>     I understand it may not be there for all cases, but at least for
>>     some cases it is there.
>>
>>
>


-- 
Louis Wasserman