Collection 太快受不了 - 集合迭代稳定性

//所有注册实例集合
private final ConcurrentHashMap<String, Map<String, Lease<InstanceInfo>>> registry
           = new ConcurrentHashMap<String, Map<String, Lease<InstanceInfo>>>();
//被修改过的实例集合,用于增量更新实例是读取
private ConcurrentLinkedQueue<RecentlyChangedItem> recentlyChangedQueue = new ConcurrentLinkedQueue<RecentlyChangedItem>();


// 注册方法使用了读锁
public void register(InstanceInfo registrant, int leaseDuration, boolean isReplication){
   read.lock();
  ...
   gMap = registry.putIfAbsent(registrant.getAppName(), gNewMap); // 往注册表内添加实例
  ...
   recentlyChangedQueue.add(new RecentlyChangedItem(leaseToCancel)); //添加最近修改队列
}
// 取消实例的注册使用读锁
protected boolean internalCancel(String appName, String id, boolean isReplication) {
   read.lock();
   Map<String, Lease<InstanceInfo>> gMap = registry.get(appName);
   Lease<InstanceInfo> leaseToCancel = null;
   if (gMap != null) {
       leaseToCancel = gMap.remove(id); // 这里开始去注册表中移除 实例
  }
  .....
   recentlyChangedQueue.add(new RecentlyChangedItem(leaseToCancel)); //添加最近修改队列
}
//更新实例的状态。使用读锁
public boolean statusUpdate(String appName, String id,
                               InstanceStatus newStatus, String lastDirtyTimestamp,
                               boolean isReplication) {
    read.lock();
   Map<String, Lease<InstanceInfo>> gMap = registry.get(appName);
   Lease<InstanceInfo> lease = null;
   if (gMap != null) {
       lease = gMap.get(id); //获取要修改的实例
  }
  ....
   lease.serviceUp(); // 对要修改的实例进行某个状态的修改
....
    recentlyChangedQueue.add(new RecentlyChangedItem(leaseToCancel)); //添加最近修改队列
}
// 下线状态赋值给实例
public boolean deleteStatusOverride(String appName, String id,
                                       InstanceStatus newStatus,
                                       String lastDirtyTimestamp,
                                       boolean isReplication) {
   read.lock();
   // 对实例进行状态修改 , 修改为下线状态
   recentlyChangedQueue.add(new RecentlyChangedItem(leaseToCancel)); //添加最近修改队列
}


//获取所有 增量实例Applications (这里是用的写锁)
public Applications getApplicationDeltas(){
    write.lock();
   Iterator<RecentlyChangedItem> iter = this.recentlyChangedQueue.iterator(); //返回最近改变的队列, 即为增量的实例
}

//被修改过的实例集合,用于增量更新实例是读取
private ConcurrentLinkedQueue<Object> map = new ConcurrentLinkedQueue<>();


public ConcurrentLinkedQueue getMap(){
   return this.map;
}


public void uploadMap(Object o){
  ConcurrentLinkedQueue copyMap =  new ConcurrentLinkedQueue();
  copyMap.addAll(map); //将当前的map 拷贝一份
  for ( o in copyMap){
      // dosomething... 开始遍历迭代或者一些耗时较长的操作
  }
  this.map = copyMap; // 修改完成后直接替换 最新的 集合
}