Smantha,

Please use the eclipse.tools.emf newsgroup/forum for questions about EMF.

More comments below.

Samantha Chan wrote:
> Hi,
>
> I have created a table view based on an EMF model.
>
> In my view, I have a label provider that extends from
> AbstractFactoryLabelProvider. I have a custom implementation of the
> content provider that does not extend from
> AbstractFactoryContentProvider. I passed a ComposedAdapterFactory to
> the label provider, so eventually it delegates to my model's item
> provider to retrieve labels and images. I believe this is pretty
> standard.
Yep.
>
> My model is updated every 3 seconds. When the model is refreshed, we
> remove one instance of a model object, and add a new one in.
Remove meaning?
> The view is updated correctly to show these changes.
>
> We expect that when the object is removed from our model, the object
> is no longer referenced by anything and it should be garbage collected.
The item providers are adapters that are attached to your objects. They
are not automatically removed.
>
> However, we have noticed that this is not the case, We found that
> none of the model objects are cleaned up after they are removed. I
> tracked it down to the item provider for the object. Our item
> providers are singleton, so we have one item provider for each model
> type. When the label provider attempts to retrieve label, the
> AdapterFactoryLabelProvider calls the AdapterFactory to adapt the
> object to its item provider. Everytime this method gets called,
> eventually the object's item provider is called to add the "notifier"
> to a "target" list. - via ItemProviderAdapter.setTarget. However,
> the object is never removed from the item provider when it is removed
> from the model. (ItemProviderAdapter.unsetTarget is never called.) As
> a result, our model objects are never garbage collected, and
> eventually we run out of memory.
The item provider has no way of knowing what 'removed from your model"
means. Even if you delete an object in the editor, you could undo the
change so the object isn't removed at all...
>
> My question is... when are the notifiers supposed to be removed from
> the ItemProviderAdapter's target list?
When the adapter factory is disposed, it removes the adapters from all
the adapted objects.
> Is this removal handled automatically when the object is removed
> from the model (via some notification?)
No.
> If not, what is the best way of removing these references?
Depending on what's easier for you, you might just call
eObject.eAdapters().clear() on the removed object(s), or you might
dispose the factory and create new ones. (Note that if you unload a
resource, all the adapters on all the contained objects are cleared.)
> Thanks for your help.
> Samantha