FL0011

GetOrAddValue is not threadsafe and should not be used with ConcurrentDictionary; use GetOrAdd instead.

GetOrAddValue is a Faithlife utility function that uses Add but doesn't use locks. This means it isn't safe for multithreading, even if you're calling it on a ConcurrentDictionary. In contrast, ConcurrentDictionary contains a GetOrAdd function that behaves well in multithreaded code (see here for details).

Consequently, GetOrAdd should be preferred over GetOrAddValue for ConcurrentDictionary.