title: Is MFC UpdateAllViews blocking or non blocking?
body: <p>I have a MFC code based on Document View framework. I use UpdateAllViews(nullptr,0,nullptr) from Document class to invoke the View's OnDraw member function. </p>
  
  <pre><code>void MyDocumentClass::MyFunction()
  {
      //.. Document code to create and process data
      UpdateAllViews(nullptr,0,nullptr) // Invokes OnDraw
      // When does program control reach this line? 
  }
  </code></pre>
  
  <p>My question is, please tell me if the UpdateAllViews function is blocking or non blocking, when does program control reach the line next to UpdateAllViews()? Does it reach there after all the code in OnDraw() has finished executing, or does it reach there sooner?</p>