LocalCache Threading Exception

Question

Hi,
When running a LocalCache (v. 3.5.3.465) and using a key extractor filter, I noticed internally (in Coherence.dll) it calls the Query method. The method tries to be “lock free” and only locks when it encounters a threading issue:
try
list = new ArrayList(cache.Keys);
catch (InvalidOperationException)
lock (cache.SyncRoot)
list = new ArrayList(cache.Keys);
The line new ArrayList(cache.Keys) calls the CopyTo method on the Keys collection. The CopyTo method generates the “Destination array to small” exception if the destination and target arrays do not match in length (which could happen with multiple threads):
if ((array.Length - index) < this.m_cache.Count)
throw new ArgumentException("Destination array is too small");
The first code then locks if an exception is thrown but catch (InvalidOperationException) catches the wrong exception. The ArgumentException is never caught and so the exception bubbles up and this brings down the local cache instance of Coherence. We have observed this behaviour multiple times.
Rgds

Answer 1

For clarification, I am referring to the Coherence.net Localcache implementation.