@Override
  public void regionReinitialized(Region<?, ?> region) {
    String regionName = region.getFullPath();
    FutureResult<InternalRegion> future = reinitializingRegions.get(regionName);
    if (future == null) {
      throw new IllegalStateException(
          String.format("Could not find a reinitializing region named %s",
              regionName));
    }
    future.set((InternalRegion) region);
    unregisterReinitializingRegion(regionName);
  }
Return true if the region is initializing.
geode-core/src/main/java/org/apache/geode/internal/cache/GemFireCacheImpl.java