The Trunk: Kernel-ul.1153.mcz

Levente Uzonyi uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-ul.1153.mcz

==================== Summary ====================

Name: Kernel-ul.1153
Author: ul
Time: 25 February 2018, 1:02:44.121313 am
UUID: 647960c4-9e41-4ad0-9190-9cac3a97f7ad
Ancestors: Kernel-tonyg.1152

-  When CroquetPlugin's primitiveGatherEntropy is available, use it to initialize the states array of Random instances.

=============== Diff against Kernel-tonyg.1152 ===============

Item was added:
+ ----- Method: Random class>>gatherEntropyInto: (in category 'entropy source') -----
+ gatherEntropyInto: aByteArray
+ "Gather good random entropy from a system source and fill up aByteArray with it. Return true upon success, else false."
+
+ <primitive: 'primitiveGatherEntropy' module: 'CroquetPlugin'>
+ ^false!

Item was changed:
  ----- Method: Random>>seed: (in category 'initialization') -----
  seed: anIntegerOrNil
  "Use the given integer as the seed, or generate one if it's nil."
 
+ (anIntegerOrNil isNil and: [ self seedWithRandomBytes ]) ifFalse: [
+ | newSeed |
+ newSeed := anIntegerOrNil ifNil: [
+ (Time utcMicrosecondClock bitShift: 28) bitXor: self hash hashMultiply ].
+ (newSeed between: 0 and: 16rFFFFFFFF) ifFalse: [
+ newSeed := self hashSeed: newSeed ].
+ self initializeStatesWith: newSeed ].
+ self generateStates!
- | newSeed |
- newSeed := anIntegerOrNil ifNil:
- [(Time utcMicrosecondClock bitShift: 28) bitXor: self hash hashMultiply].
- (newSeed between: 0 and: 16rFFFFFFFF) ifFalse:
- [newSeed := self hashSeed: newSeed].
- self
- initializeStatesWith: newSeed;
- generateStates!

Item was added:
+ ----- Method: Random>>seedWithRandomBytes (in category 'private') -----
+ seedWithRandomBytes
+ "Initialize the states array with random bytes from the VM. Return true on success, false on failure."
+
+ | randomBytes |
+ randomBytes := ByteArray new: MTn * 4.
+ (self class gatherEntropyInto: randomBytes) ifFalse: [
+ "Primitive not available"
+ ^false ].
+ states := Array new: MTn.
+ 1 to: MTn do: [ :i |
+ states at: i put: (
+ "The below code assumes that MTwordMask is 1 << 30 - 1. It avoids LargeInteger operations on 32-bit platforms. It's equivalent to:
+ (randomBytes unsignedLongAt: 1 bigEndian: true) bitAnd: MTwordMask"
+ ((randomBytes at: i * 4 - 3) bitAnd: 16r3F) * 256 +
+ (randomBytes at: i * 4 - 2) * 256 +
+ (randomBytes at: i * 4 - 1) * 256 +
+ (randomBytes at: i * 4)) ].
+ ^true!