100218: BigInteger staticRandom field

[David Holmes]

Hi Paul,

For some reason this email, despite being dated Dec 14, only just 
appeared in my inbox on Jan 3!

On 14/12/2011 12:44 AM, Paul Ciprich wrote:
> All,
>
> I've created a bug report to address a scalability problem with
> BigInteger's staticRandom field. The problem is that the shared
> staticRandom field causes bottlenecks with parallel code. The proposed
> solution is to change the staticRandom field to a ThreadLocal and eliminate
> the bottleneck by giving each thread its own copy of the SecureRandom
> object. Bug 100218 contains a patch with the proposed change if it is
> deemed acceptable.

As I mention in the bug report we have to ensure that we don't add 
unacceptable overhead to the non-concurrent case. Also I'm wondering if 
anyone might be relying on the existing SecureRandom instance being shared?

Can you clarify the context for the proposed fix: what code is the 
bottleneck (isProbablePrime?), under what conditions - is it a 
microbenchmark or real code?

Thanks,
David Holmes