boolean startEvicting() {
    while (true) {
      int value = refCount.get();
      if (value != 1) return false;
      if (refCount.compareAndSet(value, EVICTING_REFCOUNT)) return true;
    }
  }
Class used for a single file in LowLevelCacheImpl, etc.
llap-server/src/java/org/apache/hadoop/hive/llap/cache/FileCache.java