code: public synchronized void remove_async_request(final int id) {
  
          // Try to destroye Request object (added by PV 7/9/06)
          final AsyncCallObject aco =  async_request_table.get(id);
          if (aco != null) {
              removePendingRepliesOfRequest(aco.request);
              ((org.jacorb.orb.ORB) ApiUtil.getOrb()).removeRequest(aco.request);
              async_request_table.remove(id);
          }
      }
docs: GA: add synchronized