Re: question on implementing an atomic operation in GP Pari

[American Citizen <website.reader3@gmail.com>]

Thanks Bill, now all I have to do is write the correct gp pari code to 
kick off 6 cores


On 8/22/25 01:34, Bill Allombert wrote:
> On Thu, Aug 21, 2025 at 01:04:46PM -0700, American Citizen wrote:
> > Hello:
> >
> > Currently I am using 6 cores to run though a long list of primes or product
> > of primes congruent to 1 mod 4. (such as 5, 37, 65, etc)
> >
> > I split the list according to the assigned processor number 0..5 by using
> > modulus 6 values.
> >
> > While this method works, some of the processors are climbing up the list
> > faster than others.
> >
> > Currently I have
> >
> > n:88181
> > n:90889
> > n:87145
> > n:88285
> > n:88633
> > n:89245
> >
> > and you can see that the 2nd processor at 90,889 is ahead of the others. The
> > 3rd processor is behind at 87,145.
> >
> > I can use an alternate scheme, having all 6 cores access an atomic operator
> > and receiving just one unique number from the list, then incrementing the
> > index to the list, this would insure that all numbers are bunched closely
> > together.
> >
> > This requires an atomic "get and increment" operator. I do have C code which
> > does this, would this be the right way to go, to implement an external call
> > into the gp code?
> You can do that directly in GP using parfor or parforeach.
>
> Cheers,
> Bill.