Performance of Object.GetType()

Question

We have lots of logging calls in our app. Our logger takes a System.Type parameter so it can show which component created the call. Sometimes, when we can be bothered, we

Answer 1

The GetType() function is marked with the special attribute [MethodImpl(MethodImplOptions.InternalCall)]. This means its method body doesn't contain IL but instead is a hook into the internals of the .NET CLR. In this case, it looks at the binary structure of the object's metadata and constructs a System.Type object around it.

EDIT: I guess I was wrong about something ...

I said that: "because GetType() requires a new Object to be build" but it seems this is not correct. Somehow, the CLR caches the Type and always returns the same object so it doesn't need to build a new Type object.

I'm based on the following test:

Object o1 = new Object();
Type t1 = o1.GetType();
Type t2 = o1.GetType();
if (object.ReferenceEquals(t1,t2))
    Console.WriteLine("same reference");

So, I don't expect much gain in your implementation.