code: def on_parent_exit(signame):
      
      signum = getattr(signal, signame)
      def set_parent_exit_signal():
          # http://linux.die.net/man/2/prctl
          result = cdll['libc.so.6'].prctl(PR_SET_PDEATHSIG, signum)
          if result != 0:
              raise PrCtlError('prctl failed with error code %s' % result)
      return set_parent_exit_signal
docs: Return a function to be run in a child process which will trigger SIGNAME
      to be sent when the parent process dies