C++实现安全队列

```cpp

#ifndef SAFEQUEUE
#define SAFEQUEUE

#include <iostream>
#include <queue>
#include <thread>
#include <mutex>
#include <condition_variable>

using namespace std;

template<typename T>
class SafeQueue {
public:
    SafeQueue() {}

    ~SafeQueue() {}

    void InitQueue()
    {
        work = 1;
    }


    void EnQueue(T value) 
    {
        lock_guard<mutex> lock(mt);
        if (work) {
            q.push(value);
            cv.notify_one();
        }
    }

    void Print()
    {
        lock_guard<mutex> lock(mt);
        queue<T> copy_queue = q;

        while (!q.empty())
        {
            copy_queue.push(q.front());
            q.pop();
        }
        while (!copy_queue.empty())
        {
            std::cout << copy_queue.front() << std::endl;
            copy_queue.pop();
        }
    }

    int DeQueue(T& value) 
    {
        int ret = 0;
        //占用空间相对lock_guard 更大一点且相对更慢一点，但是配合条件必须使用它，更灵活
        unique_lock<mutex> lock(mt);
        //第二个参数 lambda表达式：false则不阻塞 往下走
        cv.wait(lock, [this] {return !work || !q.empty(); });
        if (!q.empty()) {
            value = q.front();
            q.pop();
            ret = 1;
        }

        return ret;
    }

    void setWork(int work) 
    {
        lock_guard<mutex> lock(mt);
        this->work = work;
    }

    void Clear() 
    {
        lock_guard<mutex> lock(mt);
        while (!q.empty())
        {
            q.pop();
        }
    }

    int Find(T value)
    {
        return nullptr;
    }

private:
    mutex mt;
    condition_variable cv;

    queue<T> q;
    //是否工作的标记 1 ：工作 0：不接受数据 不工作
    int work;
};

#endif //SAFEQUEUE