Lucee's function caching is quick and convenient. By specifying the cachedwithin parameter, a successful execution of the function has its results stored in the cache for the specified duration.

There is an issue though; if the cache is empty, all requests (concurrent or otherwise) execute that function. Once one of them 'wins', the cache is populated.

This creates unnecessary work. Overall, the system would be faster if all those other requests just waited for that first one to finish and cache the result.

Please can we make cold-cache calls to a function single threaded? I guess you'd need a `timeout` parameter as per the `lock` function.