Re: [Vala] The behaviour of G.List and other containers.

[Jürg Billeter <j bitron ch>]

Hi Alexandre,

On Tue, 2007-09-18 at 22:38 -0300, Alexandre Moreira wrote:
> What is the correct way to deal with the assisted memory management
> and Containers, such as the G.List ? I noticed that whenever I add
> something to the list, it gets automatically ref()ed, but it seems I
> can't get it to automatically unref() it. Is this the intended
> behaviour ? Am I doing something stupid ? Or is it just that I am
> supposed to rely on automatic ref()ing and then unref() by myself
> (this last option I believe is a bit odd, though) ?

The intended behavior is that Vala should take care of ref() and unref()
when adding an object to resp. removing an object from a GList or other
container. GList doesn't support calling unref/free functions on removal
by itself as for example GHashTable, so valac needs some workarounds to
accomplish correct memory management.

Those workarounds are still lacking at the moment, so it's relatively
easy to get memory leaks when working with a GList. The simple case of
adding objects to an empty list and then automatically calling unref()
for each object when the list is destroyed should work fine, though.

Please post a test case where memory management doesn't work as it
should and we'll try to fix it as soon as possible.

> I didn't quite test, but I suppose the same behaviour is replicated
> across the other glib containers, as they all share the same style of
> API.

It works fine with GHashTable as long as you pass the right callbacks to
the full constructor.

Regards,

Jürg