title: Calling MPI_Init more than once
body: <p>I understand that MPI_init can only be called more than once per executable instance. Can anyone clarify the limits of this language: ie:</p>
  
  <ol>
  <li>I know multiple python exec on mpiexec can be run.</li>
  <li>Is there anything like fork() or threads that can lead to something that qualifies? Is the criterion that they have to happen first and then invoke mpiexec?</li>
  </ol>
  
  <p>Thanks!</p>