code: public void cancelAllReservations() {
      // Inform jobs which have reserved slots on this tasktracker
      if (jobForFallowMapSlot != null) {
        unreserveSlots(TaskType.MAP, jobForFallowMapSlot);
      }
      if (jobForFallowReduceSlot != null) {
        unreserveSlots(TaskType.REDUCE, jobForFallowReduceSlot);
      }
    }
docs: Cleanup when the {@link TaskTracker} is declared as 'lost/blacklisted'
  by the JobTracker.
  
  The method assumes that the lock on the {@link JobTracker} is obtained
  by the caller.