private void tryFlush() {
      if (heapLock.tryLock()) {
        try {
          doNotifyUnderHeapLock(count, buffers);
        } finally {
          count = 0;
          heapLock.unlock();
        }
      }
    }
Wraps around the structures used in thread locals and buffers instances of LlapCachableBuffers in order to prevent
lock contention in LRFU during buffer ingress initiated heap access.
llap-server/src/java/org/apache/hadoop/hive/llap/cache/LowLevelLrfuCachePolicy.java