Mutex locking an individual queue inside a vector (or list) container of queues in C++ [closed]

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As the question suggested, I have a vector or a list of queues

template <typename T> 
class queue { 
private: 
    std::queue<T> m_queue;
    std::mutex m_mutex;
public
    void push(T item);
    T pop();
}


std::vector<queue<DefinedDataStructure>> QueueList;
std::list<queue<DefinedDataStructure>> QueueList2;

Is it possible to mutex a lock a single element like QueueList[0], which is also a queue?
If not, could you please suggest a way how I can link the individual queues together and still able to lock some of them when necessary?

I appreciate all the ideas.

  • 1

    What is queue in this example? std::queue does not have a mutex lock. If you need that, you have to add it yourself, such as by storing a std::queue and a std::mutex in a struct or class. Please clarify your situation.

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  • @RemyLebeau Let me clarify. Queue is a thread-safe class implementation of queues. “` template <typename T> class queue { private: std::queue<T> m_queue; std::mutex m_mutex; “` I’m wondering if I lock down a queue object, would it make the whole vector container inaccessible to other threads?

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  • No, it would not. You would need a separate mutex for the vector itself

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  • You could make a threadsafe vector in the same way. Make a class with a mutex like your queue class and expose methods on that new class you need. And in the implementation use std::scope_lock lock{mutex}. (do NOT inherit from std::vector it is not designed to be inherited from).

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  • Note that you cannot create a vector with your queue as its value type, since its member variable of type std::mutex does provide neither copy constructor nor move constructor. Relevant question: stackoverflow.com/q/16465633/580083.

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