expose reload executor from table data manager

Author: J-HowHuang

pinot-core/src/main/java/org/apache/pinot/core/data/manager/BaseTableDataManager.java

@@ -758,6 +758,11 @@ public ExecutorService getSegmentPreloadExecutor() {
     return _segmentPreloadExecutor;
   }
 
+  @Override
+  public ExecutorService getSegmentReloadRefreshExecutor() {
+    return _segmentReloadRefreshExecutor;
+  }
+
   @Override
   public boolean isDeleted() {
     return _isDeleted;

pinot-segment-local/src/main/java/org/apache/pinot/segment/local/data/manager/TableDataManager.java

@@ -297,6 +297,12 @@ default List<SegmentDataManager> acquireSegments(List<String> segmentNames,
    */
   ExecutorService getSegmentPreloadExecutor();
 
+  /**
+   * Returns the executor used for segment reload and refresh operations.
+   * Can be used to submit work that should run with the same concurrency controls as segment reloads.
+   */
+  ExecutorService getSegmentReloadRefreshExecutor();
+
   /**
    * Add error related to segment, if any. The implementation
    * is expected to cache last 'N' errors for the table, related to