使用ConcurrentSkipListMap的并发测试队列(Concurrent Testing Queue using ConcurrentSkipListMap)

 我最近不得不完成其中一个面试编码练习。 基本上它需要实现一个消息队列类： 
 
 
 
 根据传入消息中的优先级字段维护项目。 
 
 
 消息可以通过message.priorityField值范围在高，中，低三个优先级类别之一中控制。 
 
 
 有一个getSize和isEmpty方法。 
 
 
 有一个地方（消息）方法。 
 
 
 有一个删除方法。 
 
 
 有getFront（）方法（返回最高优先级的消息） 
 
 
 我最后没有详细介绍的是实现一个MessageQueue类，它在内部使用ConcurrentSkipListMap（一个并发和有序的映射）来保存消息。 
 
 我还实现了一个基本的JUnit测试用例，用于测试基本的业务需求。 
 
 现在因为它是一个消息传递队列，因此消息可以同时进入，我需要测试实现的当前方面。 
 
 我现在越来越接近问题的核心了。 
 
 我的想法是，当单个线程与实现交互时，基本的JUnit测试用例应该验证代码是否有效。 
 
 然后，我实现了一个并发测试用例，该测试用例应验证实现的当前方面。 
 
 现在问题是：我应该测试哪些并发方面？ 
 
 我唯一能想到的是让多个生产者线程在队列中注入方法，以及多个消费者线程来删除消息（通过getFront（））。 这里验证的是队列中的任何消息最终都会消失。 
 
 但那够了吗？ 可以在这里测试哪些其他并发方面？ 
 
 另外值得注意的是，我已经提交了解决方案，所以无论你提出什么建议都不会对我申请这份工作的机会产生任何影响。 

I recently had to complete one of these job interview coding exercises. Basically it required implementing a message queue class that:
 
 
 
maintains items based on a priority field in the incoming message.
 
 
the message can be in one of three priority categories high, medium, low controlled via message.priorityField value range.
 
 
has a getSize and isEmpty methods.
 
 
has a place(message) method.
 
 
has a remove method.
 
 
has getFront() method (which returns highest priority message)
 
 
What I did in the end without going into too much detail is implement a MessageQueue class that internally uses ConcurrentSkipListMap (a concurrent and ordered map) to hold the messages.
 
I also implemented a basic JUnit test case that tests for basic business requirements.
 
Now as its a messaging queue and hence messages can come in concurrently of course I need to test the occurrent aspect of the implementation.
 
I'm getting closer to the heart of the question now.
 
My thinking is that the basic JUnit test case should verify the code works when a single thread is interacting with the implementation.
 
I then implemented a concurrent test case which should verify the occurrent aspect of the implementation.
 
Now here is the question: What concurrent aspects should I be testing for?
 
The only thing I can think of is having multiple producer threads that inject methods in the queue and multiple consumer threads that remove the messages (via getFront()) . What is being verified here is that whatever messages went in the queue will eventually come out.
 
But is that enough? what other concurrent aspects could be tested for here?
 
Also worth noting that I have already submitted the solution so whatever you suggested will not have any impact on my chances for this job I applied for.

原文：https://stackoverflow.com/questions/14618982