C# Memory & Types.

Where C# values live, when they are copied, and what the runtime does with them afterwards. Covers 10 sub-skills.

• C# Memory & Types · 1 of 3

  Struct layout

  What does an empty value type still take?

  Aa single byte of roomBno room of any kindCno fields of any kindDa single field of room

• C# Memory & Types · 2 of 3

  Garbage collection

  What does a large allocation skip?

  Athe oldest generation entirelyBthe younger generations entirelyCthe same younger generation at firstDthe oldest generation at first

• C# Memory & Types · 3 of 3

  Weak references

  A memory leak hunt finds objects alive that only a weak handle should reach. What does the measurement point at?

  static WeakReference<List<int>> Make() => new WeakReference<List<int>>(new List<int> { 1, 2 });var w = Make();Console.WriteLine(w.TryGetTarget(out var before) + " " + (before?.Count.ToString() ?? "none"));GC.Collect();GC.WaitForPendingFinalizers();GC.Collect();Console.WriteLine(w.TryGetTarget(out var after) + " " + (after?.Count.ToString() ?? "none"));

  Aa weak handle still in some scopeBa fetched value still in some handleCa fetched value still in some scopeDa weak handle still in some table