Locking pattern for proper use of .NET MemoryCache

Question

I assume this code has concurrency issues:

const string CacheKey = \"CacheKey\";
static string GetCachedData()
{
    string expensiveString =null;
    if (Me         


        

Answer 1

There is an open source library [disclaimer: that I wrote]: LazyCache that IMO covers your requirement with two lines of code:

IAppCache cache = new CachingService();
var cachedResults = cache.GetOrAdd("CacheKey", 
  () => SomeHeavyAndExpensiveCalculation());

It has built in locking by default so the cacheable method will only execute once per cache miss, and it uses a lambda so you can do "get or add" in one go. It defaults to 20 minutes sliding expiration.

There's even a NuGet package ;)