This code seems to do a good job of caching async method results. I would like to add some sort of expiration to it. I have tried Tuple but I was not successful in getting it to fully work / compile.
private static readonly ConcurrentDictionary<object, SemaphoreSlim> _keyLocks = new ConcurrentDictionary<object, SemaphoreSlim>();
private static readonly ConcurrentDictionary<object, Tuple<List<UnitDTO>, DateTime>> _cache = new ConcurrentDictionary<object, Tuple<List<UnitDTO>, DateTime>>();
public async Task<string> GetSomethingAsync(string key)
{
string value;
// get the semaphore specific to this key
var …