connect_to_event_source_one;
connect_to_event_source_two;
use Anyevent;


sleep($sometime);

if($internal_variable == $something_else){
      do_some_action;
      event_source_two recv;
     if($internal_variable2 == $new_expected_external_state)    {
     yet_another_action;
     }
}
Anyevent::condvar->recv;