[OLPC-devel] Re: [sugar] Pygtk and garbage collecting

[Federico Mena Quintero]

On Mon, 2006-07-31 at 17:32 +0200, Philip Van Hoof wrote:

> In case of tinymail the GtkTreeModel that holds a reference on all the
> headers of the current folder, is such an object. 
> 
> model = MsgHeaderListModel ()
> treeview.set_model (model)
> 
> newmodel = MsgHeaderListModel ()
> treeview.set_model (newmodel)
> 
> Will not immediately mark "model" for garbage collection (when model
> goes out of scope). Adding a gc.collect(), however, will. 

The usual idiom  is to have a way to explicitly dispose an object which
holds a reference to a non-GC resource.  In C# you do

  obj = new SomeObject ();
  treeview.set_model (obj);

  newobj = new SomeObject ();
  treeview.set_model (newobj);

  obj.Dispose ();

or use syntactic sugar:

  using (Gdk.Pixbuf pixbuf = new Gdk.Pixbuf ("foo.jpg")) {
      do_something_with_pixbuf (pixbuf);
  } /* exiting the "using" block disposes the pixbuf */

This is pretty useful for managed objects which maintain non-managed
data (file descriptors, memory buffers, database connections, etc.).

Does Python let you do something like this?

  Federico