Pop Catalin Sever wrote:
1) if LongRunningMethod() acceses fields on MyObject instance the "this" parameter is passed on the stack to the method meaning you have a rooted reference to the object instance, the method call practicaly is like this

newobj MyObject //Returns a reference in the stack

What you're not seeing is that the JITter helps the GC know when the reference is no longer needed. In this case the MyObject reference is needed only to invoke the call to LongRunningMethod, but isn't needed afterward. If a GC occurs during LongRunningMethod the instance may be collected if there are no other rooted references to the object.

See here if you want code to reproduce the behavior.