Map<Integer, NodePort> reassignment = new HashMap<Integer, NodePort>();
List<NodePort> reassignSlots=null;
List<NodePort> sortedFreeSlots = sortSlots(freedSlots);
//��ȡ�������Ҫ�������slots�ڵ�
if (customAssignment != null) {
reassignSlots = customAssignment.slotsAssignment(sortedFreeSlots, reassign_num,reassignIds);
} else {
if (sortedFreeSlots != null) {
reassignSlots = sortedFreeSlots.subList(0, reassign_num);
}