C# to lock or not to lock

Question

Fearing I already know the answer. I have a class that handles services calls and caching. To avoid multiple calls to the service with the same request, I can of course use a lock around the code block but a lot of these methods have varying arguments which make up the cache key. It seems a shame to wait for a lock code block to execute when it could be for a completely different cache key (or multiple different cache keys).

I know I could do a lock on the cache key string itself but this is a no-no given that that string could potentially pop up anywhere.

So, I can either perform potential unnecessary calls to the service without the lock OR add potentially unnecessary delays within the method by waiting for the lock.

Are those my only 2 options or is there another?

Cheers

Answer 1

You could, potentially, switch your types around to use a thread safe class, such as a ConcurrentDictionary<T,U>, to handle your caching. Used appropriately, this would prevent the need for locking (of your own), as you could rely on the fine grained locking built into the concurrent collection itself.