Oh, I see. We have to give up on the MerseneTwisterRNG in tests and just use the JRE. Is that OK?
On Sat, Jan 16, 2010 at 5:44 PM, Olivier Grisel <olivier.gri...@ensta.org> wrote: > 2010/1/16 Drew Farris <drew.far...@gmail.com>: >> On Sat, Jan 16, 2010 at 4:42 PM, Benson Margulies <bimargul...@gmail.com> >> wrote: >>> . Running through strace showed >>>> that something was attempting to reading from /dev/random. Sometimes >>>> it ran fine, but at least 25-30% it ended up blocking until the >>>> entropy pool is refilled. To test I moved /dev/random, and created a >>>> link from /dev/urandom to /dev/random (the former doesn't block, but >>>> isn't cryptographically secure). It looks as if this could be related >>>> to the loading of the SecureRandomSeedGenerator class. >>> >>> Why not use a fixed random seed for unit tests? That would make them >>> more repeatable and avoid this problem, no? >>> >> >> It appears we are. in RandomUtils: >> >> public static Random getRandom() { >> return testSeed ? new MersenneTwisterRNG(STANDARD_SEED) : new >> MersenneTwisterRNG(); >> } >> >> But something somewhere is forcing SecureRandomSeedGenerator to get >> loaded by the classloader which in turn does a 'new SecureRandom()' in >> a private static final field assignment. Trying to track down what is >> causing the generator to get loaded in the first place. >> >> But something is forcing the SecureRandomSeedGenerator class to get >> loaded, which I suspect >> > > > MersenneTwisterRNG constructor calls: > > this(DefaultSeedGenerator.getInstance().generateSeed(SEED_SIZE_BYTES)); > > Which in turn calls: > > private static final SeedGenerator[] GENERATORS = new SeedGenerator[] > { > new DevRandomSeedGenerator(), > new RandomDotOrgSeedGenerator(), > new SecureRandomSeedGenerator() > }; > > In the definition of the class: DefaultSeedGenerator > > Unless the forking tests are disabled I don't see how to prevent the > MersenneTwisterRNG to inderctly fetch entropy from /dev/random / > SecureRandom. > -- > Olivier > http://twitter.com/ogrisel - http://code.oliviergrisel.name >