Re: ConcurrentModificationException

[Brian W. <bwe...@xb...>]

On Thu, 10 Oct 2002, Brian Wellington wrote:

> > Just going through some servlet logs and found this:
> > 
> > java.util.ConcurrentModificationException
> > 	at java.util.HashMap$HashIterator.nextEntry(HashMap.java:750)
> > 	at java.util.HashMap$KeyIterator.next(HashMap.java:786)
> > 	at org.xbill.DNS.Cache$CacheCleaner.clean(Cache.java:120)
> > 	at org.xbill.DNS.Cache$CacheCleaner.run(Cache.java:152)
> > 
> > I'm using the 1.3.0 beta; I have no context information and no idea what 
> > it was I did that led to this (sorry), but I thought it might be useful 
> > if I passed this info on.
> > 
> > For what it's worth, I've got lots of little threads doing DNS lookups 
> > at various times, but this exception seems to be a lower level problem.
> 
> Thanks.  I can reproduce this by running a program which does a lot of 
> queries in combination with aggressive cache cleaning, so it shouldn't be 
> too hard to fix.

OK, fixed.  You can either get the current code from CVS, or just modify 
Cache.java::CacheCleaner::clean() to catch ConcurrentModificationException 
around the iterator.

Brian