question: private void updateLru ( CacheItem < K , V > item ) { long lruCounter = _lruCounter ; long itemCounter = item . _lruCounter ; long delta = ( lruCounter - itemCounter ) & 0x3fffffff ; if ( _lruTimeout < delta || delta < 0 ) { updateLruImpl ( item ) ; } }
target:  Put item at the head of the used-twice lru list. This is always called while synchronized.