protected void lockBucketCreationAndVisit(BucketVisitor visitor) {
    StoppableWriteLock lock = bucketCreationLock.writeLock();
    lock.lock();
    try {
      visitBuckets(visitor);
    } finally {
      lock.unlock();
    }
  }
sent by the partitioned region when its loader has changed
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegionDataStore.java