Re: question on implementing an atomic operation in GP Pari

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.
>