private void releaseDirectBufferMemory() {
    SystemInfo.getInstance().decreaseDirectBufferMemoryCost(directBufferMemoryCost);
    // avoid repeated deletion
    this.directBufferMemoryCost = 0;
  }
Release all threads waiting for this data region successfully deleted
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/DataRegion.java