The Trunk: Network-topa.166.mcz

Tobias Pape uploaded a new version of Network to project The Trunk:
http://source.squeak.org/trunk/Network-topa.166.mcz

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

Name: Network-topa.166
Author: topa
Time: 21 October 2015, 8:26:14.656 pm
UUID: d6d9910f-fa67-4c69-9a89-030c81233e90
Ancestors: Network-topa.165

UUIDGenerator
 - Use new Random>>#nextBytes:into:startingAt: (needs Kernel-ul.960) for even more speed
 - Fix UUIDGenerator class>>#initialize to correctly register at startup
 - Do not reset default on startup but rather reseed TheRandom

Timings improved:  '1,190,000 per second. 842 nanoseconds per run.' (0.25 times slower than primitive version)

=============== Diff against Network-topa.165 ===============

Item was changed:
  Object subclass: #UUIDGenerator
+ instanceVariableNames: ''
- instanceVariableNames: 'bits'
  classVariableNames: 'Default TheRandom TheSemaphore'
  poolDictionaries: ''
  category: 'Network-UUID'!
 
  !UUIDGenerator commentStamp: 'topa 10/19/2015 23:23:19' prior: 0!
  I generate a pseudo-random UUID by asking Random for a 128 bit value.
 
  See https://tools.ietf.org/html/rfc4122.html#section-4.4 for reference.!

Item was changed:
  ----- Method: UUIDGenerator class>>default (in category 'instance creation') -----
  default
+ ^ Default ifNil: [Default := self new]
+ !
- Default ifNil: [self generateDefault].
- ^Default!

Item was removed:
- ----- Method: UUIDGenerator class>>generateDefault (in category 'instance creation') -----
- generateDefault
- Default := self new!

Item was changed:
  ----- Method: UUIDGenerator class>>initialize (in category 'class initialization') -----
  initialize
  TheRandom := Random new.
  TheSemaphore := Semaphore forMutualExclusion.
+ Smalltalk addToStartUpList: self!
- Smalltalk addToStartUpList: self after: nil.!

Item was added:
+ ----- Method: UUIDGenerator class>>resetDefault (in category 'class initialization') -----
+ resetDefault
+ Default := nil.!

Item was changed:
  ----- Method: UUIDGenerator class>>startUp (in category 'class initialization') -----
  startUp
+ "Reseed the random"
+ TheSemaphore critical: [TheRandom seed: nil].!
- Default := nil!

Item was added:
+ ----- Method: UUIDGenerator>>fillRandomly: (in category 'instance creation') -----
+ fillRandomly: aUUID
+
+ TheSemaphore critical: [
+ TheRandom nextBytes: 16 "128 bit" into: aUUID startingAt: 1].!

Item was changed:
  ----- Method: UUIDGenerator>>generateBytes:forVersion: (in category 'instance creation') -----
+ generateBytes: aUUID forVersion: aVersion
+ | versionID fixedValue |
+
+ aVersion = 4 ifFalse: [^ self error: 'Unsupported version'].
+
+ self fillRandomly: aUUID.
+ versionID := ((aUUID at: 7) bitAnd: 16r0F) bitOr: 16r40. "Version 4"
+ fixedValue := ((aUUID at: 9) bitAnd: 16r3F) bitOr: 16r80. "Fixed 8..b value"
+ aUUID
+ at: 7 put: versionID;
+ at: 9 put: fixedValue.!
- generateBytes: aPlaceHolder forVersion: aVersion
- aVersion = 4 ifTrue: [self generateFieldsVersion4]
- ifFalse: [self error: 'Unsupported version'].
- self placeFields: aPlaceHolder.!

Item was removed:
- ----- Method: UUIDGenerator>>generateFieldsVersion4 (in category 'instance creation') -----
- generateFieldsVersion4
-  
- TheSemaphore critical: [
- bits := 16rffffffffffffffffffffffffffffffff atRandom: TheRandom. "128 bit"].!

Item was removed:
- ----- Method: UUIDGenerator>>placeFields: (in category 'instance creation') -----
- placeFields: aByteArray
-
- | version fixed |
- bits isLarge
- ifTrue: [ aByteArray replaceFrom: 1 to: bits size with: bits]
- ifFalse: [aByteArray unsignedLongAt: 1 put: bits bigEndian: false].
-
- version := ((aByteArray at: 7) bitAnd: 16r0F) bitOr: 16r40. "Version 4"
- fixed := ((aByteArray at: 9) bitAnd: 16r3F) bitOr: 16r80. "Fixed 8..b value"
- aByteArray
- at: 7 put: version;
- at: 9 put: fixed.!

On Thu, Oct 22, 2015 at 06:28:09AM +0000, [hidden email] wrote:
This is outstanding. The UUID plugin has long been a source of problems in
the VM, partly due to issues in various Linux distributions.

  http://bugs.squeak.org/view.php?id=7358

Making the plugin unnecessary is a big improvement.

Dave

On 22.10.2015, at 14:37, David T. Lewis <[hidden email]> wrote:

Thats what I thought.
Probably we want to present this (Mersenne PRNG + new UUID gen) to
the Pharo core developers (cc) so that we can just remove the UUID plugin
from the VMs (cc vm-dev)?

Best regards
        -Tobias

That sounds good!

        Marcus

I added an issue tracker entry so we do not forget:

        https://pharo.fogbugz.com/f/cases/16846/integrate-non-Plugin-UUIDGenerator-from-Squeak


        Marcus

--
Marcus Denker  —  2Denker GmbH
http://www.2denker.de 

In the release version of Squeak 5.0, the Mersenne Twister is initialized using a single seed restricted to 32bit.
Has this been changed since to use a wider ranged value?
Otherwise, you run into problems with potential collisions from separate image starts rather too fast for UUID uses... (IMHO)

Cheers,
Henry

On Thu, 22 Oct 2015, Henrik Johansen wrote:

No, that's still something to be done[1].

Levente

[1] http://lists.squeakfoundation.org/pipermail/squeak-dev/2015-October/186409.html

>
> Cheers,
> Henry
>