Main     Thread     Thread
  |         |          |
  |         |          |
  |      Critical   Blocked
  |      Section    Blocked
  |         |          |
  |      Blocked    Critical
  |      Blocked    Section
  |        |           |




Main     Thread     Thread
  |         |          |
  |     Call Sync      |
  |_________/          |
  |                    |
Blocked                |
Running                |
Thread                 |
 Code                  |
  |                    |
  \_________           |
            |          |
            |          |