RFR: JDK-8277175 : Add a parallel multiply method to BigInteger [v3]

[Remi Forax]

----- Original Message -----
> From: "Bernd Eckenfels" <ecki at zusammenkunft.net>
> To: "core-libs-dev" <core-libs-dev at openjdk.java.net>
> Sent: Jeudi 18 Novembre 2021 12:07:19
> Subject: Re: RFR: JDK-8277175 : Add a parallel multiply method to BigInteger [v3]

> What about a new API multiply method which takes an forkjoinpool, and only if
> that is used/specified it will use the parallel mode (and only if Notsitzes
> threshold applies?). Most of the pool tuning can then done with this argument.
> It also avoids surprise threads.

You don't need it, here is the usual trick if you want to specify a specific fork join pool
https://stackoverflow.com/questions/21163108/custom-thread-pool-in-java-8-parallel-stream

> 
> Gruss
> Bernd

regards,
Rémi

> --
> http://bernd.eckenfels.net
> ________________________________
> Von: core-libs-dev <core-libs-dev-retn at openjdk.java.net> im Auftrag von kabutz
> <duke at openjdk.java.net>
> Gesendet: Thursday, November 18, 2021 11:41:40 AM
> An: core-libs-dev at openjdk.java.net <core-libs-dev at openjdk.java.net>
> Betreff: Re: RFR: JDK-8277175 : Add a parallel multiply method to BigInteger
> [v3]
> 
> On Thu, 18 Nov 2021 07:26:45 GMT, David Holmes <dholmes at openjdk.org> wrote:
> 
>> To add my 2c IMO a parallel version of this type absolutely **must** be opt-in.
>> There are simply far too many side-effects of using the FJP and multiple
>> threads to perform the calculation in parallel as if it is just a minor
>> implementation detail. A clear API is 1000x better than a "kill switch".
>>
>> And yes you may still need to expose some kind of tuning knob.
>>
>> David
> 
> Yes, it **must** be opt-in. However I'm not sure that a tuning knob will be
> necessary. BigInteger has thresholds for using different multiply algorithms
> and these are also not configurable.
> 
> -------------
> 
> PR: https://git.openjdk.java.net/jdk/pull/6409