Java - 在 ConcurrentSkipListMap 上同步线程是否可以接受？

Question

我有一个程序，其中许多线程将其请求发送到 PriorityQueue 。随后，他们等待 ConcurrentSkipListMap 的回复。 。有一个线程发布了 ConcurrentSkipListMap 的答案.

以下代码行说明了这一点:

在程序初始化时

PriorityQueue<Request> requests = new PriorityQueue<Request>();
ConcurrentSkipListMap<Long, Reponse> responsesReceived = new ConcurrentSkipListMap<Long, Reponse>();

在调用者线程中

// Send request ...
Request r = ... // Elaborate the request 
requests.add(r);

// ... then wait for an answer
Long id = r.getId();
while (responsesReceived.containsKey(id) == false) {
    synchronized (responsesReceived) {
         responsesReceived.wait();
    }
}

Answer a = responsesReceived.take(id);

// Do other things ...

在响应处理程序线程中

// Wait for a remote answer
Answer answer = ...;

// Once received publish it in ConcurrentSkipListMap
responsesReceived.put(answer.getRequestId(), answer);

synchronized (responsesReceived) {
    responsesReceived.notify();
}

// Go back and wait for a new answer...

问题

• 在ConcurrentSkipListMap上同步调用者线程和响应处理程序线程是否安全？ ？
• 我应该使用锁进行同步吗？
• 我应该使用 HashMap锁(HashMap<Long,Object>)？

我对 java.util.concurrent API 还很陌生，我有一些疑问......

Answer 1

通过synchronized/wait/notify，你可以使用任何对象作为锁。至于将作业提交到队列并等待其结果，请查看 ExcutorService、Future 和 CompletionService。