const UnicodeString& ICULocaleService::validateFallbackLocale() const { const Locale& loc = Locale::getDefault(); ICULocaleService* ncThis = (ICULocaleService*)this; { Mutex mutex(&ncThis->llock); if (loc != fallbackLocale) { ncThis->fallbackLocale = loc; LocaleUtility::initNameFromLocale(loc, ncThis->fallbackLocaleName); ncThis->clearServiceCache(); } } return fallbackLocaleName; }