Hi Johan,
Be careful, it is not the object that will execute the finalizing code but
a shallow copy of it.
It can lead to deep debugging session sometimes ;-)
o := Object new.
WeakRegistry default add: o. "a shallow copy of o is registered"
o := nil.
Smalltalk garbageCollect.
"the shallow copy of o will receive the finalize message"
Cheers,
Luc
2015-01-14 19:13 GMT+01:00 Johan Fabry <jfa...@dcc.uchile.cl>:
>
> Yes, adding it to the weak registry does the trick! Thank you Esteban for
> the pointer and Torsten for the magic line of code WeakRegistry default
> add: anObject.
> Being able to hook into the GC in this way is extremely cool, it saves me
> a lot of housekeeping work and I am very happy because of that !
>
> > On Jan 13, 2015, at 17:35, Torsten Bergmann <asta...@gmx.de> wrote:
> >
> > Esteban wrote:
> >> you also need to register the object for cleanup, in the WeakRegistry.
> >> (not on my machine, sorry I cannot put an example, but look around)
> >
> > It is simple and here is an example:
> >
> >
> > Create a class:
> >
> > Object subclass: #Bar
> > instanceVariableNames: 'id'
> > classVariableNames: ''
> > category: 'Foo'
> >
> > implemented an #initialize method
> >
> > initialize
> > super initialize.
> > id := UUID new.
> > Transcript show: 'Initialized ', id printString; cr
> >
> > and implemented a finalization method:
> >
> > finalize
> >
> > Transcript show: 'Finalized ', id printString; cr
> >
> > Now in the workspace I instantiate the object:
> >
> > |anObject|
> > Transcript open; clear.
> > anObject := Bar new.
> > Transcript flush.
> > WeakRegistry default add: anObject.
> >
> > and by forcing garbage collection in a second step I can
> > see that the finalization method is working:
> >
> > 3 timesRepeat: [ Smalltalk garbageCollect ].
> > Transcript flush.
> >
> >
> > And I get the following output
> >
> > Initialized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4
> > Finalized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4
> >
> > If it doesnt work check your VM for updates.
> >
> > I'm using Pharo4.0 Latest update: #40442 on Windows with the following
> VM:
> > Win32 built on Sep 4 2014 01:13:32 Compiler: 4.6.2 VMMaker
> versionString https://github.com/pharo-project/pharo-vm.git
> > Commit: c7bc23dd6053d5f9934f7dd427537f76fc96eb32 Jenkins build #14851
> >
>
>
>
> ---> Save our in-boxes! http://emailcharter.org <---
>
> Johan Fabry - http://pleiad.cl/~jfabry
> PLEIAD lab - Computer Science Department (DCC) - University of Chile
>
>
>
