JDK 9 RFR of 8026236: Add PrimeTest for BigInteger [TEST-ONLY]

[Florian Weimer]

On 05/05/2014 11:17 PM, Brian Burkhalter wrote:
> Joe / Paul,
>
> Thanks for the comments. This an aggregate response to your two
> messages. An updated version of the patch is here:
>
> http://cr.openjdk.java.net/~bpb/8026236/webrev.03/

The command line parsing is off by one, I think, it should check for >= 
instead of >:

   54         // Prepare arguments
   55         int upperBound = args.length > 1 ? 
Integer.valueOf(args[0]) : DEFAULT_UPPER_BOUND;
   56         int certainty = args.length > 2 ? Integer.valueOf(args[1]) 
: DEFAULT_CERTAINTY;
   57         boolean parallel = args.length > 3 ? 
Boolean.valueOf(args[2]) : true;

I think this line should go, it doesn't match the shifted indexing:

   98         //bs.set(0, 2, true);

There are some very long lines:

  120         NavigableSet<BigInteger> primes = bs.stream().mapToObj(p 
-> BigInteger.valueOf(p + 2)).collect(toCollection(TreeSet::new));

  180         List<BigInteger> bigInts = (new 
SplittableRandom()).ints(NUM_NON_PRIMES, 2, 
maxPrime).mapToObj(BigInteger::valueOf).filter(b -> 
!b.isProbablePrime(certainty)).collect(toList());


The arithmetic in checkPrime() is unnecessary because isProbablePrime() 
will never report a prime as a non-prime (the Monte-Carlo vs Las Vegas 
thing), so the count will always be exact because you feed it only 
primes.  It is impossible to check for the expected number of failures 
(non-primes reported as primes) in checkNonPrimes() because this would 
result in a test that fails sporadically.

-- 
Florian Weimer / Red Hat Product Security Team