title: How to show MBProgressHUD on iPhone without spawning new threads?
body: <p>I want to show an <code>MBProgressHUD</code> in my iPhone app without spawning new threads. </p>
  
  <p>I have a very complicated set of business logic which sometimes (but not always) needs to wait for user input, and running on multiple threads ends up asking for user input multiple times at once, leading to crazy errors. Thus I would prefer to avoid running anything off of the main thread. However, due to this constraint, <code>MBProgressHUD</code> is not showing because the main thread is being blocked! Normally I would create my <code>MBProgressHUD</code> with the following code:</p>
  
  <pre><code>[HUD showWhileExecuting:@selector(myWorkerMethod) onTarget:self withObject:nil animated:YES];
  </code></pre>
  
  <p>But I would like to use the following code without blocking the main thread:</p>
  
  <pre><code>HUD = [[MBProgressHUD alloc] initWithView:self.view];
  [self.view addSubview:HUD];
  HUD.delegate = self;
  HUD.minShowTime = 0.0;
  HUD.labelText = @"some text";
  [HUD show:YES];
  </code></pre>
  
  <p>Any thoughts?</p>