private boolean tableFull( int reprobe_cnt, int len ) {
      return
        // Do the cheap check first: we allow some number of reprobes always
        reprobe_cnt >= REPROBE_LIMIT &&
        (reprobe_cnt >= reprobe_limit(len) ||
         // More expensive check: see if the table is > 1/2 full.
         _slots.estimate_get() >= (len>>1));
    }
Auto-boxing version of {@link #replace}.
jctools-core/src/main/java/org/jctools/maps/NonBlockingHashMapLong.java