K 10 svn:author V 3 jhb K 8 svn:date V 27 2009-01-28T19:05:18.336610Z K 7 svn:log V 346 Convert the global mutex protecting the directory lookup name cache from a mutex to a reader/writer lock. Lookup operations first grab a read lock and perform the lookup. If the operation results in a need to modify the cache, then it tries to do an upgrade. If that fails, it drops the read lock, obtains a write lock, and redoes the lookup. END