Andreas L Delmelle wrote:
Hi Andreas,
<snip/>
Just looked closer, and I may have found a slightly better way of
dealing with it.
Since the cause of the problem is CacheCleaners interfering with
rehash(), maybe the below patch is a better approach.
Once rehash() has been entered, and has acquired the lock on the first
segment, set a flag. A CacheCleaner will then only be launched if there
is no rehash in progress.
Your patch has been running all day in my tests and I haven't seen the
NPE, so it looks good. Before I commit it I have one question: how does
this mechanism avoid CacheCleaner threads clearing the ref attribute if
they are already running when the rehash method is called. Having the
flag in rehash is a bit like a one way sync lock. I would have thought
it would be safer for cache cleaner threads and the rehash method to
synchronize on a common object so that neither interferes with each other.
WDYT?
Thanks,
Chris
