what if the object stores a reference to itself? then you can access it from the shadow copy?
On Thu, Jan 15, 2015 at 4:39 AM, Johan Fabry <jfa...@dcc.uchile.cl> wrote: > > Yes, in the end it’s not working out for me, sadly. I think it’s because > of that, but I’m not sure as it’s complicated … I’ll show you next week if > you want to know more. > > On Jan 14, 2015, at 16:14, Luc Fabresse <luc.fabre...@gmail.com> wrote: > > 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 >> >> >> > > > > ---> Save our in-boxes! http://emailcharter.org <--- > > Johan Fabry - http://pleiad.cl/~jfabry > PLEIAD lab - Computer Science Department (DCC) - University of Chile > >
