RFR: JDK-8266431: Dual-Pivot Quicksort improvements (Radix sort)

iaroslavski github.com+43264149+iaroslavski at openjdk.java.net
Tue Sep 14 10:08:14 UTC 2021

On Tue, 14 Sep 2021 09:23:23 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> @richardstartin And one more addon: my first version of Radix sort, see my github https://github.com/iaroslavski/sorting/tree/master/radixsort uses another name, like skipBytes, then renamed to passLevel.
>> So, the common part is "skip". And this method has different number of parameters. I don't see any collision with your code.
>> Hi @iaroslavski I'm unconvinced that this work was from 14/06/2020 - I believe this work derives from an unsigned radix sort I implemented on 10/04/2021 [richardstartin/radix-sort-benchmark at ab4da23#diff-6c13d3fb74f38906677dbfa1a70a123c8e5baf4a39219c81ef121e078d0013bcR226](https://github.com/richardstartin/radix-sort-benchmark/commit/ab4da230e1d0ac68e5ee2cee38d71c7e7d50f49b#diff-6c13d3fb74f38906677dbfa1a70a123c8e5baf4a39219c81ef121e078d0013bcR226) which has numerous structural similarities to this work:
>> Moreover, @bourgesl forked my repository on 11/04/2021 and communicated with me about doing so. On 25/04/2021 there was a new implementation of `DualPivotQuicksort` with a signed radix sort but the same structural similarities, and with the same method and variable names in places [bourgesl/radix-sort-benchmark at 90ff7e4#diff-397ce8fd791e2ce508cf9127201bc9ab46264cd2a79fd0487a63569f2e4b59b2R607-R609](https://github.com/bourgesl/radix-sort-benchmark/commit/90ff7e427da0fa49f374bff0241fb2487bd87bde#diff-397ce8fd791e2ce508cf9127201bc9ab46264cd2a79fd0487a63569f2e4b59b2R607-R609)
> @iaroslavski The attribution is not clear here. Can you provide a summary as to who is contributing to this patch? I can't tell if all involved have signed the OCA or not. I'm sure there will be questions about space/time trade-offs with radix sort but I think it's important to first establish the origins of this patch first.

@AlanBateman There was discussion with Richard Startin, where Laurent and I explained the origin of my patch. There was misunderstanding based on git changes only. Finally Richard wrote comment in PR on May 13, 2021,
I duplicate it here:

"In private correspondence with Vladimir, it was explained that where Vladimir's code and Laurent's code are identical, including typos (Vladimir's code, Laurent's code) it is because Vladimir sent the code to Laurent, not the other way around, therefore Vladimir's code does not derive from Laurent's, and it does not derive from mine. I can only trust that this is the case, so please disregard my claim that this is derivative work when reviewing this PR."

@AlanBateman Vertical pipeline of PR hides comments in the middle and you have to click on "Show more..." to see all comments. There are no claims related to the origin of my patch, it doesn't violate any rights.


PR: https://git.openjdk.java.net/jdk/pull/3938

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