RFR 8012647: Add Arrays.parallelPrefix (prefix sum, scan, cumulative sum)

[Chris Hegarty]

On 12/06/2013 16:38, Paul Sandoz wrote:
>
> On Jun 12, 2013, at 4:50 PM, Chris Hegarty<chris.hegarty at oracle.com>  wrote:
>
>> Add implementations of parallelPrefix() in Arrays for Object, int, long, and double arrays.
>>
>> Specdiff:
>> http://cr.openjdk.java.net/~chegar/8012647/ver.00/specdiff/java/util/Arrays.html
>> Webrev:
>>   http://cr.openjdk.java.net/~chegar/8012647/ver.00/webrev/
>>
>> This work was done over in the lambda forest mainly by Doug Lea, with some small spec updates by myself.
>>
>
> The API looks fine to me.

Thanks Paul.

> The example text could be moved to an @apiNote.

Yes, possibly.

>> Note: Some work still need to be done to clean up the test, but I would like to focus mainly on the API and try to get it finalized first.
>>
>
> OK, i will still note some comments on the test:
>
> 1) it could be better named;

Agreed.

> 2) uses random data, and if a test fails there is no way to reproduce from that data; and

Yes this is a problem, and needs to be fixed.

> 3) Could use a sprinkling of @DataProvider for various sizes, taking into account the threshold, minimum partition size and ForkJoinPool.getCommonPoolParallelism().

Good idea.

Let's finalize the API, start CCC, and I can refactor/cleanup the test 
in the lambda forest concurrently.

-Chris
>
> Paul.
>