June 2013 - Pharo-users - lists.pharo.org

Re: [Pharo-users] implementing #release in a domain object

by Sven Van Caekenberghe

Paul, On 26 Jun 2013, at 23:47, Paul DeBruicker <pdebruic(a)gmail.com> wrote: > Lets say I'm modeling a navy that is comprised of many ships each with > their own soldiers and jobs. If I want one of the ships to be GC'd do I > need to implement #release in the soldier and job objects and send it to > each of those soldiers and jobs that live and work on the ship I want > GC'd or is removing the references between the ship and the navy enough > to have the whole ship (including its soldiers and jobs) GC'd? GC is automatic memory management. Whenever something is no longer reachable by following pointers from a a know starting set, the system dictionary, the stack and some other places, it automatically becomes garbage and the memory it occupies will be reused. Of course, if you keep a reference to an object, on purpose or by accident, the object will never become garbage and it will keep on occupying memory. Especially circular references can be hard to track. There are indeed a couple of common messages that are sometimes used to break possible references by nilling out instance variables etc. #close, #stop, #unregister and indeed #release. Often, these are also used to manage external resources (open files, sockets â¦). You can use any message to do this, there is no framework that you have to follow. And then there are also finalization and weak references, which are related, but more advanced. Sven

June 26, 2013

Re: [Pharo-users] implementing #release in a domain object

by Camillo Bruni

ok I was not sure of how much you were aware of how the GC works :) second try: In your example it would be enough to cut the connection the ship, everything "aboard" will be GC'ed as well. Once you cut the connection to a subgraph of objects, and they are no longer reachable from the outside (root objects) the whole subgraph get's garbage collected. In your example: as soon as nobody references a ship anymore it gets garbage collected, as well as all objects that were only reachable via that ship. clearer? If not I suggest you quickly make your own little example. Note that with #allInstances you can see which objects are still around of a certain class, for instance: Dictionary allInstances On 2013-06-27, at 00:13, Paul DeBruicker <pdebruic(a)gmail.com> wrote: > In Pharo2 Object (and many other classes) implement #release and > #release has many senders. So I don't understand how 'there is no such > thing as #release in Pharo'. I understand that the GC is a VM thing and > it does not send #release to the objects in the image. > > > IF in my hypothetical question the Navy object contains an ordered > collection of ships, and each ship is referenced in that collection and > also by all of its soldiers and jobs, to have my ship GC'd do I only > need to remove the reference to the ship in the Navy object (at which > point the ship becomes detached and self contained amalgamation of > soldiers and jobs) or do I have to have each soldier and job dereference > the ship too? > > > > > On 06/26/2013 03:05 PM, Camillo Bruni wrote: >> There is no such thing as #release in Pharo. If you want your objects >> to be garbage collected just make sure to remove all references to it. >> You simply assign nil to instance variables which previously held such >> and object. >> >> Does that answer your question? >> >> On 2013-06-26, at 23:47, Paul DeBruicker <pdebruic(a)gmail.com> wrote: >>> Lets say I'm modeling a navy that is comprised of many ships each with >>> their own soldiers and jobs. If I want one of the ships to be GC'd do I >>> need to implement #release in the soldier and job objects and send it to >>> each of those soldiers and jobs that live and work on the ship I want >>> GC'd or is removing the references between the ship and the navy enough >>> to have the whole ship (including its soldiers and jobs) GC'd? >> > >

June 26, 2013

Re: [Pharo-users] implementing #release in a domain object

by Paul DeBruicker

In Pharo2 Object (and many other classes) implement #release and #release has many senders. So I don't understand how 'there is no such thing as #release in Pharo'. I understand that the GC is a VM thing and it does not send #release to the objects in the image. IF in my hypothetical question the Navy object contains an ordered collection of ships, and each ship is referenced in that collection and also by all of its soldiers and jobs, to have my ship GC'd do I only need to remove the reference to the ship in the Navy object (at which point the ship becomes detached and self contained amalgamation of soldiers and jobs) or do I have to have each soldier and job dereference the ship too? On 06/26/2013 03:05 PM, Camillo Bruni wrote: > There is no such thing as #release in Pharo. If you want your objects > to be garbage collected just make sure to remove all references to it. > You simply assign nil to instance variables which previously held such > and object. > > Does that answer your question? > > On 2013-06-26, at 23:47, Paul DeBruicker <pdebruic(a)gmail.com> wrote: >> Lets say I'm modeling a navy that is comprised of many ships each with >> their own soldiers and jobs. If I want one of the ships to be GC'd do I >> need to implement #release in the soldier and job objects and send it to >> each of those soldiers and jobs that live and work on the ship I want >> GC'd or is removing the references between the ship and the navy enough >> to have the whole ship (including its soldiers and jobs) GC'd? >

June 26, 2013

Re: [Pharo-users] implementing #release in a domain object

by Camillo Bruni

There is no such thing as #release in Pharo. If you want your objects to be garbage collected just make sure to remove all references to it. You simply assign nil to instance variables which previously held such and object. Does that answer your question? On 2013-06-26, at 23:47, Paul DeBruicker <pdebruic(a)gmail.com> wrote: > Lets say I'm modeling a navy that is comprised of many ships each with > their own soldiers and jobs. If I want one of the ships to be GC'd do I > need to implement #release in the soldier and job objects and send it to > each of those soldiers and jobs that live and work on the ship I want > GC'd or is removing the references between the ship and the navy enough > to have the whole ship (including its soldiers and jobs) GC'd?

June 26, 2013

implementing #release in a domain object

by Paul DeBruicker

Lets say I'm modeling a navy that is comprised of many ships each with their own soldiers and jobs. If I want one of the ships to be GC'd do I need to implement #release in the soldier and job objects and send it to each of those soldiers and jobs that live and work on the ship I want GC'd or is removing the references between the ship and the navy enough to have the whole ship (including its soldiers and jobs) GC'd?

June 26, 2013

Slide share

by StÃ©phane Ducasse

Hi guys we created a slideshare acount for pharo I added 2009 smalltalks slides 2011 ESUG 2013 Pharo Conference a new lecture Intro Model Syntax http://www.slideshare.net/pharoproject/ Can you tell me if you can see the 2013 pharo conference? Do you know if there are limits on the number of presentations that we can upload, because I see (get public on this presentation => go pro). So I wonder if I want to invest in slideshare.

June 26, 2013

Motecello repository not committing methods(resources) of WAFileLibrary subclass

by Thushar G R

I find that WAFileLibrary subclasses resource methods cannot be committed to Monticello repository. Is this normal? These resources have been added by the WAFileLibrary->addFilesIn:method. But when i try to create another method and then commit, i find that the new method gets committed and that i can load it on a different image without issues. So then i filed out the WAFileLibrary subclass , and removed it from the image, and then i again filed it in. After when i commit, all the resource method gets committed and its seems things are fine. But why am i not able to commit it soon after creating the class , adding resources by addFilesIn: as such? Also i find that someone else have reported same issue in squeak list. http://permalink.gmane.org/gmane.comp.lang.smalltalk.squeak.seaside/27891 Thanks, Thushar

June 26, 2013

Re: [Pharo-users] ODBC Maintainer? was: Re: Pharo 2.0 and ODBC

by Mariano Martinez Peck

Actually, I don't know how is the maintainer of ODBC. Now sure if there is one. As a comment, notice that OpenDBXDriver can also talk to ODBC backend. The thing here is that instead of doing: Pharo -> ODBC you are doing: Pharo -> openDBX -> ODBC OpenDBX author recommends to use ODBC directly or any of the other drivers when connecting when to a particular DB. But anyway, you could use OpenDBX with ODBC if you want. I didn't try myself so I cannot tell much. I know some people did it, but I think it was on Windows. Cheers, On Wed, Jun 26, 2013 at 4:06 AM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > > On 26 Jun 2013, at 08:59, Friedrich Dominicus < > frido(a)q-software-solutions.de> wrote: > > > Can anyone point me to the current ODBC maintainers? > > I would start searching here: http://dbxtalk.smallworks.com.ar > > > Regards > > Friedrich > > -- > > Q-Software Solutions GmbH; Sitz: Bruchsal; Registergericht: Mannheim > > Registriernummer: HRB232138; Geschaeftsfuehrer: Friedrich Dominicus > > > > > -- Mariano http://marianopeck.wordpress.com

June 26, 2013

Error âCant Find EOCD positionâ while loading project from Monticello

by Thushar G R

I Have set up an Monticello HTTP repository in my Windows pc. After i published my project in pharo 2.0 on to the repository from my Mac. Later i tried to load the project on another 2.0 image in windows and i found this error. Cant Find EOCD position. But i am able to load the project in another image in mac. Anybody have some idea what must be missing?

June 26, 2013

Re: [Pharo-users] ODBC Maintainer? was: Re: Pharo 2.0 and ODBC

by Sven Van Caekenberghe

On 26 Jun 2013, at 08:59, Friedrich Dominicus <frido(a)q-software-solutions.de> wrote: > Can anyone point me to the current ODBC maintainers? I would start searching here: http://dbxtalk.smallworks.com.ar > Regards > Friedrich > -- > Q-Software Solutions GmbH; Sitz: Bruchsal; Registergericht: Mannheim > Registriernummer: HRB232138; Geschaeftsfuehrer: Friedrich Dominicus >

June 26, 2013