[Pharo-project] FreeType and finalization

Igor Stasenko siguctua at gmail.com
Tue Oct 12 08:21:14 EDT 2010


2010/10/12 Gary Chambers <gazzaguru2 at btinternet.com>:
> Hi all, I've encountered a problem with FreeType with respect to the new
> finalization scheme.
> http://code.google.com/p/pharo/issues/detail?id=3096
> Regards, Gary
>

FT2HandleRegistry overrides following method:

add: anObject
	"Add anObject to the receiver. Store the object as well as the
associated executor."
	| executor dup |
	executor := anObject executor.
	dup := nil.
	self protected:[
		dup := valueDictionary detect: [ :v | v handle = executor handle ]
ifNone: [ ].
		valueDictionary at: anObject put: executor.
	].
	dup ifNotNil: [ self error: 'Duplicate object added!'. self remove: anObject ].
	^anObject


As i see, the intent is to prevent registering a same handle twice,
so in own turn, when time will come, a #finalize won't attempt to
destroy same handle twice.

The proposed fix (as you wrote in issue tracker)

registry
	^Registry ifNil: [ Registry := WeakRegistry new]

appears to fix the problem...

But apparently its not the same as in original.
Okay, but since we never seen  the error: 'Duplicate object added!',
then i think it may work without it :)

Still, it would be good to know, how handles are created, and what the
chances that they could be duplicated.

-- 
Best regards,
Igor Stasenko AKA sig.




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