I'm not a developer, but to be honest, thought that's how all non-trivial caching implementations worked -- instead of going directly to the back end or having

I'm not a developer, but to be honest, thought that's how all non-trivial caching implementations worked -- instead of going directly to the back end or having each one trigger a read from the back end for a cache-miss, all of the threads that want that resource just waited on it to appear in the cache.