Re: How to protect dynamic lookup content when it is changing?

I guess you could synchronize all access methods on a common lock, but
don't use the lookup itself for sync, as the actual underlying object might
change.

Or use a ReadWriteLock as usual.

But Steven's suggestion is probably the right way to go. Don't forget to
use weak listeners or unsubscribe listeners manually.

On Oct 11, 2016 09:27, "Steven Yi" <[email protected]> wrote:

> Not knowing the complete context, I'm wondering if you could change
> the architecture such that rather than have another thread that might
> poll the lookup data, you could modify the code to use a
> LookupListener and react when modifications have occurred.
>
> On Tue, Oct 11, 2016 at 7:33 AM, rsobies <[email protected]> wrote:
> > i would like to block accesing lookup content when another thread is
> puting into lookup.
> > here is an example
> >
> >
> > Code:
> >
> > public class MyNode extends AbstractNode {
> >
> >     private InstanceContent instanceContent = new InstanceContent();
> >
> >     public MyNode(SomeKey key) {
> >         this(key, new InstanceContent());
> >     }
> >
> >     private CarNode(SomeKey key, InstanceContent ic) {
> >         super(Children.LEAF, new AbstractLookup(ic));
> >
> >         this.instanceContent = ic;
> >         instanceContent.add(key);
> >     }
> >
> >     public void setNewKey(SomeKey key) {
> >         Collection<? extends SomeKey> lookupAll =
> getLookup().lookupAll(SomeKey.class);
> >         for (Object item : lookupAll) {
> >             remove(item);
> >         }
> >
> >  //at this time lookup is empty, if another thread tries to get content,
> it gets null
> >
> >         instanceContent.add(key);
> >     }
> > }
> > }
> >
> >
> >
> >
> > is there an elegant way to block getLookup().lookup(SomeKey.class)
> during execution of setNewKey()?
> >
> >
> >
> >
>