On 15/11/2012 05:28, Mike Duigou wrote:
This bug appears to have been present as far back as Java 6 when NavigableSet
was introduced. I could only check 6u33 but it seems unlikely to have been
broken during the course of Java 6 maintenance releases.
As these are views which pass through mutation to the parent object I believe
there are fewer compatibility concerns than might be expected.
Compatibility concern would mostly involve use of the returned entrySetView for
synchronization. Previously synchronization on the returned views would have
been partially ineffectual because a new view object was returned every time.
Sharing the returned views would have synchronized correctly but any other
access to the source object either directly or through other views would have
led to problems with concurrent modification of the source treemap.
In the repaired implementation where a single view object is returned
synchronization on the views would now be more effective and prevent concurrent
race errors. It's possible that new deadlock conditions might be introduced but
this seems unlikely.
Mike
It does look like it has been there from the NS were added.
I think it's safe to fix this and the change looks fine to me.
-Alan
