title: Unity "ContainerControlled" Singletons and multi-threaded method calling
body: <p>I'm using Microsoft Unity for Dependency Injection (DI).  My classes are basically static (in functionality but not coding/calling conventions) except that I want DI, so I use Unity and Constructors which auto-resolve other Unity classes.</p>
  
  <p>Since this is a singleton pattern, can multiple threads execute the same code block at the same time?  </p>
  
  <p>i.e. Let's say I have an Add method, which returns an int, and takes as input, two ints...</p>
  
  <p>Can multiple-threads invoke this Add method on the same singleton object, at the same time?  Or because it's the same instance, do threads block waiting to invoke?</p>
  
  <p>To put it another way, is there any difference between method calling for a static method, vs. a singleton instance method?</p>
  
  <p>(I know any shared data used from within the singleton instance methods must be made thread safe)</p>