private void _log(String logMsg) {

    if (_isCurrentlyOnMainThread()) {
      _logs.add(0, logMsg + " (main thread) ");
      _adapter.clear();
      _adapter.addAll(_logs);
    } else {
      _logs.add(0, logMsg + " (NOT main thread) ");

      // You can only do below stuff on main thread.
      new Handler(Looper.getMainLooper())
          .post(
              new Runnable() {

                @Override
                public void run() {
                  _adapter.clear();
                  _adapter.addAll(_logs);
                }
              });
    }
  }