Package io.github.pr0methean.betterrandom.prng.adapter

Class EntropyBlockingSplittableRandomAdapter

java.lang.Object

java.util.Random

io.github.pr0methean.betterrandom.prng.BaseRandom

io.github.pr0methean.betterrandom.prng.adapter.BaseSplittableRandomAdapter

io.github.pr0methean.betterrandom.prng.adapter.SplittableRandomAdapter

io.github.pr0methean.betterrandom.prng.adapter.EntropyBlockingSplittableRandomAdapter

All Implemented Interfaces:

ByteArrayReseedableRandom, EntropyCountingRandom, Java8CompatRandom, RepeatableRandom, Dumpable, Serializable

public class EntropyBlockingSplittableRandomAdapter
extends SplittableRandomAdapter

A SplittableRandomAdapter that blocks waiting to be reseeded if its entropy drops too low. Reseeding is done on a SimpleRandomSeeder if provided, and on the calling thread otherwise. Entropy count is thread-local, so consuming entropy on one thread won't directly cause blocking on another thread.

See Also:

Serialized Form

Field Summary

Fields inherited from class io.github.pr0methean.betterrandom.prng.adapter.SplittableRandomAdapter

threadLocal

Fields inherited from class io.github.pr0methean.betterrandom.prng.BaseRandom

ENTROPY_OF_DOUBLE, ENTROPY_OF_FLOAT, entropyBits, lock, randomSeeder, seed, superConstructorFinished

Constructor Summary

Constructors

Constructor	Description
EntropyBlockingSplittableRandomAdapter(SeedGenerator seedGenerator, SimpleRandomSeeder randomSeeder, long minimumEntropy)	Creates an instance.
EntropyBlockingSplittableRandomAdapter(SimpleRandomSeeder randomSeeder, long minimumEntropy)	Creates an instance.

Method Summary

Modifier and Type	Method	Description
protected BaseRandom	createDelegate()	Creates the delegate for the calling thread.
protected void	debitEntropy(long bits)	Record that entropy has been spent, and schedule a reseeding if this PRNG has now spent as much as it's been seeded with.
byte[]	getSeed()	Returns the calling thread's seed, not the master seed.
protected java8.util.SplittableRandom	getSplittableRandom()	Returns the SplittableRandom that is to be used to generate random numbers for the current thread.
void	setSeed(byte[] seed)	Reseed this PRNG.
void	setSeed(long seed)	Sets the seed of this random number generator using a single long seed, if this implementation supports that.

Methods inherited from class io.github.pr0methean.betterrandom.prng.adapter.SplittableRandomAdapter

addSubclassFields, equals, getEntropyBits, hashCode, nextGaussian, setRandomSeeder, setSeedInternal, toString, usesParallelStreams

Methods inherited from class io.github.pr0methean.betterrandom.prng.adapter.BaseSplittableRandomAdapter

getNewSeedLength, lockForNextGaussian, next, nextBoolean, nextBytes, nextDouble, nextDouble, nextDoubleNoEntropyDebit, nextFloat, nextInt, nextInt, nextInt, nextLong, nextLong, nextLongNoEntropyDebit, preferSeedWithLong, unlockForNextGaussian, withProbabilityInternal

Methods inherited from class io.github.pr0methean.betterrandom.prng.BaseRandom

checkLength, creditEntropyForNewSeed, doubles, doubles, doubles, doubles, dump, entropyOfInt, entropyOfLong, fallbackSetSeedIfInitialized, gaussians, gaussians, getRandomSeeder, initTransientFields, internalNextGaussian, ints, ints, ints, ints, longs, longs, longs, longs, needsReseedingEarly, nextDouble, nextElement, nextElement, nextEnum, nextLong, supportsMultipleSeedLengths, withProbability

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

EntropyBlockingSplittableRandomAdapter

public EntropyBlockingSplittableRandomAdapter(SimpleRandomSeeder randomSeeder,
                                              long minimumEntropy)

Creates an instance.

Parameters:

randomSeeder - the SimpleRandomSeeder that will reseed this. Its seed generator is also used on the calling thread to generate an initial seed when this EntropyBlockingSplittableRandomAdapter is used the first time on each thread.

minimumEntropy - the minimum entropy; operations that would drop the entropy below this amount will instead block until the calling thread's PRNG is reseeded. Should generally be zero or negative.

EntropyBlockingSplittableRandomAdapter

public EntropyBlockingSplittableRandomAdapter(@Nullable
                                              SeedGenerator seedGenerator,
                                              SimpleRandomSeeder randomSeeder,
                                              long minimumEntropy)

Creates an instance.

Parameters:

seedGenerator - the seed generator that will generate an initial PRNG seed for each thread

randomSeeder - the SimpleRandomSeeder that will reseed this

minimumEntropy - the minimum entropy; operations that would drop the entropy below this amount will instead block until the calling thread's PRNG is reseeded. Should generally be zero or negative.

Method Detail

createDelegate

protected BaseRandom createDelegate()

Description copied from class: SplittableRandomAdapter

Creates the delegate for the calling thread.

Overrides:

createDelegate in class SplittableRandomAdapter

Returns:

the thread-local delegate

setSeed

public void setSeed(byte[] seed)

Reseed this PRNG.

Most subclasses should override BaseRandom.setSeedInternal(byte[]) instead of this method, so that they will deserialize properly.

Applies only to the calling thread.

Specified by:

setSeed in interface ByteArrayReseedableRandom

Overrides:

setSeed in class BaseRandom

Parameters:

seed - The PRNG's new seed.

setSeed

public void setSeed(long seed)

Sets the seed of this random number generator using a single long seed, if this implementation supports that. If it is capable of using 64 bits or less of seed data (i.e. if {@link #getNewSeedLength()} <= {@link Long#BYTES}), then this method shall replace the entire seed as Random.setSeed(long) does; otherwise, it shall either combine the input with the existing seed as SecureRandom.setSeed(long) does, or it shall generate a new seed using the DefaultSeedGenerator. The latter is a backward-compatibility measure and can be very slow. Applies only to the calling thread.

Specified by:

setSeed in interface Java8CompatRandom

Overrides:

setSeed in class BaseRandom

getSplittableRandom

protected java8.util.SplittableRandom getSplittableRandom()

Description copied from class: BaseSplittableRandomAdapter

Returns the SplittableRandom that is to be used to generate random numbers for the current thread. (SplittableRandom isn't thread-safe.) Called by all the next* methods.

Overrides:

getSplittableRandom in class SplittableRandomAdapter

Returns:

the SplittableRandom to use with the current thread.

getSeed

public byte[] getSeed()

Returns the calling thread's seed, not the master seed.

Specified by:

getSeed in interface RepeatableRandom

Overrides:

getSeed in class SplittableRandomAdapter

Returns:

the seed for the calling thread

debitEntropy

protected void debitEntropy(long bits)

Description copied from class: BaseRandom

Record that entropy has been spent, and schedule a reseeding if this PRNG has now spent as much as it's been seeded with.

Overrides:

debitEntropy in class SplittableRandomAdapter

Parameters:

bits - The number of bits of entropy spent.