[news.eclipse.newcomer] Re: Thread Safe EMF Collections

[Ed Merks <Ed.Merks@xxxxxxxxx>]

Fran,

It's best to ask about EMF on the EMF newsgroup, which I've added to the "to" list of the reply.   No there are no thread safe collections in EMF.   I suppose we could have things like Collections.synchronizedXyz but I'm convinced that having them is probably useless and if anything is actually more likely to cause problem than to solve problems.  Consider for example that code like this isn't thread safe even if the list itself is thread safe.

int index = list.indexOf(x);
list.remove(x);

The point being that higher level logic built on thread safe data structures will still not generally be thread safe.

Also consider that modifying a list produces notifications and the handling of those notifications could invoke arbitrary and long running logic. Holding a lock during this processing might well lead to deadlock.  In my opinion, the only way to achieve thread safety is at the application level with a carefully managed threading policy.

The EMF Transaction component might well appropriate for whatever problem you're trying to solve...


Fran wrote:

Which of the available EMF (EList etc.) collections is thread safe in the same way as java.util.Vector?