code: int getMaxActualSlots(JobConf conf, int numCpuOnTT, TaskType type) {
      return getMaxSlots(conf, numCpuOnTT, type);
    }
docs: Get the actual max number of tasks.  This may be different than
  get(Max|Reduce)CurrentMapTasks() since that is the number used
  for scheduling.  This allows the CoronaTaskTracker to return the
  real number of resources available.
  
  @param conf Configuration to look for slots
  @param numCpuOnTT Number of cpus on TaskTracker
  @param type Type of slot
  @return Actual number of map tasks, not what the TaskLauncher thinks.