title: Is it possible to use mutex in multiprocessing case on Linux/UNIX ?
body: <p>This is an interview question. </p>
  
  <p>Is it possible to use mutex in multiprocessing  case on Linux/UNIX ? </p>
  
  <p>My idea:
  No, different processes have separate memory space. </p>
  
  <p>mutex is only used for multithreading. </p>
  
  <p>semaphore is used for multiprocessing to do synchronization. </p>
  
  <p>right ? </p>
  
  <p>Any comments are welcome. </p>
  
  <p>thanks</p>