The Trunk: Tests-nice.142.mcz

Nicolas Cellier uploaded a new version of Tests to project The Trunk:
http://source.squeak.org/trunk/Tests-nice.142.mcz

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

Name: Tests-nice.142
Author: nice
Time: 21 February 2012, 3:00:38.727 pm
UUID: 6af7860f-3bab-4beb-890b-c8bebe9a2b31
Ancestors: Tests-nice.141

Depending on the VM, I have testBecomeIdentityHash sometimes failing...
As the test was not very expressive, I rewrote it to explain the purpose of identityHash preservation,.
Doing so, I also isolated the bad behaviour description previously tested:

   The VM is spawning too many equal identityHash to be honest

This happens on my COG version and this might require further analysis...

=============== Diff against Tests-nice.141 ===============

Item was changed:
  ----- Method: BecomeTest>>testBecomeIdentityHash (in category 'Testing') -----
  testBecomeIdentityHash
+ | a b c d numberOfRetry newAIdentityHash newBIdentityHash oldAIdentityHash oldBIdentityHash |
+ numberOfRetry := 0.
+
+ [a := 'ab' copy.
- "Note. The identity hash of both objects seems to change after the become:"
-
- | a b c d |
-
- a := 'ab' copy.
  b := 'cd' copy.
+ "Note: the sets are allocated with enough room to reduce probability that two different hash lead to same slot"
+ (c := IdentitySet new: 1000) add: a; add: b.
+ (d := IdentitySet new: 1000) add: a.
+ oldAIdentityHash := a identityHash.
+ oldBIdentityHash := b identityHash.
+ oldAIdentityHash = oldBIdentityHash and: [numberOfRetry < 10]]
+ whileTrue: [numberOfRetry := numberOfRetry + 1].
+ self assert: oldAIdentityHash ~= oldBIdentityHash description: 'The VM is spawning too many equal identityHash to be honest'.
- c := a.
- d := b.
-
  a become: b.
+ newAIdentityHash := a identityHash.
+ newBIdentityHash := b identityHash.
+ self
+ "The set c & d can still retrieve their elements because elements did not change their expected position"
+ assert: (c includes: a);
+ assert: (c includes: b);
+ assert: (d includes: a);
+ deny: (d includes: b);
+ "Elements didn't change their expected position because identityHash did not change"
+ assert: oldAIdentityHash = newAIdentityHash;
+ assert: oldBIdentityHash = newBIdentityHash!
-
- self
- assert: a identityHash = c identityHash;
- assert: b identityHash = d identityHash;
- deny: a identityHash = b identityHash.
- !