source: CIVL/examples/concurrency/mp_root.cvh

$input int NPROCS;
$proc __procs[NPROCS];
_Bool __start = 0;
$gcomm COMM_WORLD;

void MPI_Process (int rank);

void init() {
  for (int i=0; i<NPROCS; i++)
    __procs[i] = $spawn MPI_Process(i);
}

void finalize() {
  for (int i=0; i<NPROCS; i++) {
    $yield();
    $wait(__procs[i]);
  }
}

void main() {
  $atomic{
    init();
    COMM_WORLD = $gcomm_create($here, NPROCS);
    __start = 1;
    finalize();
    $gcomm_destroy(COMM_WORLD, NULL);
  }
}