private void initializeVisibleAsyncEventQueueIds(InternalRegionArguments internalRegionArgs) {
    Set<String> visibleAsyncEventQueueIds = new CopyOnWriteArraySet<>(getAsyncEventQueueIds());
    // Remove all internal aeqIds from internal region args if necessary
    if (internalRegionArgs.getInternalAsyncEventQueueIds() != null) {
      visibleAsyncEventQueueIds.removeAll(internalRegionArgs.getInternalAsyncEventQueueIds());
    }
    this.visibleAsyncEventQueueIds = visibleAsyncEventQueueIds;
  }
Use ONLY imSync for IndexManager get and set.

@return {@link IndexManager} lock.
geode-core/src/main/java/org/apache/geode/internal/cache/AbstractRegion.java