CPP异步队列

原创已于 2023-08-25 21:56:22 修改 · 196 阅读

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#c++

于 2023-08-25 20:42:08 首次发布

本文介绍了如何使用C++实现一个无容量限制的异步队列，通过`std::queue`模板类，利用`std::mutex`和`std::condition_variable`实现线程安全，支持任务添加和获取功能，同时提供停止操作以控制队列行为。

C Plus Plus implement of a Async Queue, the capacity is not limited.

#include <mutex>
#include <condition_variable>
#include <queue>

/*
    blocked task queue
    if is empty, the getTask is blocked
    TODO: limit the capcity of the queue
*/
template<class T>
class AsyncQueue: public std::queue<T>
{
public:
    ~AsyncQueue()
    {
        if(!m_stopped)
            stop();
    }

    void addTask(const T &task)
    {
        std::unique_lock<std::mutex> lock(m_mutex);
        this->push(task);
        m_cvNotEmpty.notify_one();
    }

    //return false when stopped, else block until not empty
    bool getTask(T &task)
    {
        std::unique_lock<std::mutex> lock(m_mutex);

        while (this->empty())
        {
            m_cvNotEmpty.wait(lock);

            if (m_stopped)
                return false;
        }

        task = std::move(this->front());
        this->pop();

        return true;
    }

    // stop even queue is not empty
    void stop()
    {
        m_stopped = true;
        m_cvNotEmpty.notify_all();
    }

private:
    bool                    m_stopped{false};
    std::mutex              m_mutex;
    std::condition_variable m_cvNotEmpty;
};