LRUCacheSemaphore_explicit_release.cs

    public class LRUCacheSemaphore<T>
    {
        ...
        
        public object Get(int key)
        {
                _sem.Wait();
                if (!_records.ContainsKey(key)) return null;

                _freq.Remove(key);
                _freq.AddLast(key);
                
                _sem.Release();

                return _records[key].CacheValue;
        }
        ...
   }