2009/5/7 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
> Wait, there is a bug in scanFor: fixCollisionsFrom: does not recycle
> the first nil and scanFor: then loops indefinitely :( see
> http://bugs.squeak.org/view.php?id=7350 for update
>
> 2009/5/7 Andreas Raab <andreas.raab at gmx.de>:
>> Nicolas Cellier wrote:
>>>
>>> Created http://bugs.squeak.org/view.php?id=7350
>>
>> Thanks, this is great. Is this approach applicable to weak dictionaries as
>> well?
>>
>
> Should inquire, but it's getting late...

Oh yes, it could...
but WeakRegistry will not appreciate those assoc values being garbaged
out without calling #finalize first...
Maybe #finalize could be sent directly by WeakKeyDictionary ?

WeakRegistry are protected forMutualExclusion, WeakKeyDictionary is not.
So WeakRegistry must stay.
There might be more subtle things you know better than me...
... like finalizeValues is two folds:
1) clean-up valueDictionary in a protected block
2) finalize outside this block
Didn't get why... could #finalize have a chance to modify valueDictionary ?

Nicolas

>
>> Cheers,
>>  - Andreas
>>
>>> 2009/5/6 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
>>>>
>>>> Ah, I forgot to accept one change!
>>>> It's even better if we decrease the tally when recycling a nil slot in
>>>> #fixCollisionsFrom:
>>>>
>>>> Nicolas
>>>>
>>>> 2009/5/6 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
>>>>>
>>>>> Though I have tried to attack it with some tricky combinations, I did
>>>>> not found a problem with current implementation.
>>>>> It was funny to see how nil is handled as any other object in WeakSet
>>>>> fixCollisionsFrom: (scanFor: nil works).
>>>>>
>>>>> However, it's a pity not to recycle all those nils until next grow!
>>>>> Here comes a little trial for recycling reclaimed nil slots in Pharo
>>>>> (seems compatible with 3.10.2).
>>>>> No guarantee... Note there is no WeakSet tests in Pharo nor 3.10.2
>>>>> currently :(
>>>>>
>>>>> Nicolas
>>>>>
>>>>> 2009/5/6 Andreas Raab <andreas.raab at gmx.de>:
>>>>>>
>>>>>> Nicolas Cellier wrote:
>>>>>>>
>>>>>>> Take this example:
>>>>>>
>>>>>> Ah, good point. (it works fine with o1 = 'g' and o2 = o3 = o4 = 'd').
>>>>>> The
>>>>>> thing is that the test in WeakSet>>add: was misleading - it tests for
>>>>>> nil
>>>>>> where scanFor: searches only for flag.
>>>>>>
>>>>>> Cheers,
>>>>>>  - Andreas
>>>>>>
>>>>>>> ws := WeakSet new.
>>>>>>> array := WeakSet new instVarAt: (WeakSet allInstVarNames indexOf:
>>>>>>> 'array').
>>>>>>> o1 hash \\ array size + 1 -> 1.
>>>>>>> o2 hash \\ array size + 1 -> 2.
>>>>>>> o3 hash \\ array size + 1 -> 1.
>>>>>>> ws add: o1; add: o2; add: o3.
>>>>>>>
>>>>>>> o1 := o2 := nil.
>>>>>>> Smalltalk garbageCollect.
>>>>>>> "o1 and o2 are reclaimed."
>>>>>>> (array at: 1) -> nil.
>>>>>>> (array at: 2) -> nil.
>>>>>>>
>>>>>>> o4 hash \\ array size + 1 -> 1.
>>>>>>> ws add o4.
>>>>>>> (array at: 1) -> o4.
>>>>>>>
>>>>>>> (ws includes: o3) -> false.
>>>>>>>
>>>>>>> I will try and build a test case. Should be easy with Fractions.
>>>>>>>
>>>>>>> 2009/5/6 Andreas Raab <andreas.raab at gmx.de>:
>>>>>>>>
>>>>>>>> Nicolas Cellier wrote:
>>>>>>>>>
>>>>>>>>> Isn't that dangerous if you don't fixCollisionsFrom: index ?
>>>>>>>>
>>>>>>>> Why would it? All this does is avoiding to update the tally ivar if
>>>>>>>> we're
>>>>>>>> replacing a previously reclaimed entry with a new value. And I don't
>>>>>>>> think
>>>>>>>> that #fixCollisionsFrom: even looks at tally.
>>>>>>>>
>>>>>>>> Cheers,
>>>>>>>>  - Andreas
>>>>>>>>
>>>>>>>>> Nicolas
>>>>>>>>>
>>>>>>>>> 2009/5/6 Andreas Raab <andreas.raab at gmx.de>:
>>>>>>>>>>
>>>>>>>>>> Adrian Lienhard wrote:
>>>>>>>>>>>
>>>>>>>>>>> I haven't had time to look into this very closely yet but maybe
>>>>>>>>>>> somebody
>>>>>>>>>>> else already knows what is going on. My guess is that the
>>>>>>>>>>> NewSymbols
>>>>>>>>>>> weak
>>>>>>>>>>> set is repeatedly grown since tally is not decreased if the GC
>>>>>>>>>>> removes
>>>>>>>>>>> a
>>>>>>>>>>> weak element.
>>>>>>>>>>
>>>>>>>>>> That's an excellent guess. Try changing WeakSet to e.g.,
>>>>>>>>>>
>>>>>>>>>> WeakSet>>atNewIndex: index put: aValue
>>>>>>>>>>  "Add newValue at the given index. Don't increment tally
>>>>>>>>>>  if current slot is nil since a previous value has been collected"
>>>>>>>>>>  (array at: index) ifNil:[^array at: index put: aValue].
>>>>>>>>>>  ^super atNewIndex: index put: aValue
>>>>>>>>>>
>>>>>>>>>> Cheers,
>>>>>>>>>>  - Andreas
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>
>>>
>>
>>
>>
>