private void makeDestroyed() {
    try {
      thread.shutdown();
      state = DESTROYED;
      if (logger.isTraceEnabled(LogMarker.DLS_VERBOSE)) {
        logger.trace(LogMarker.DLS_VERBOSE, "DLockGrantor {} state is DESTROYED",
            dlock.getName());
      }
      if (untilDestroyed.getCount() > 0) {
        untilDestroyed.countDown();
      }
      if (whileInitializing.getCount() > 0) {
        whileInitializing.countDown();
      }
      dlock.getDistributionManager().removeMembershipListener(membershipListener);
    } finally {
      dlock.getStats().incGrantors(-1);
    }
  }
Shuts down the grantor thread and changes internal state to destroyed.
geode-core/src/main/java/org/apache/geode/distributed/internal/locks/DLockGrantor.java