code: public void fireServiceDeactivated() {
          if (!activated.compareAndSet(true, false)) {
              return;
          }
  
          try {
              for (IoServiceListener l : listeners) {
                  try {
                      l.serviceDeactivated(service);
                  } catch (Throwable e) {
                      ExceptionMonitor.getInstance().exceptionCaught(e);
                  }
              }
          } finally {
              disconnectSessions();
          }
      }
docs: Calls {@link IoServiceListener#serviceDeactivated(IoService)}
  for all registered listeners.