C++线程安全队列

Posted on 2019-09-23 16:21  yacbo  阅读(2477)  评论(0编辑  收藏  举报

C++线程安全队列

#ifndef COMMON_SOURCE_CPP_THREADSAFE_QUEUE_H_
#define COMMON_SOURCE_CPP_THREADSAFE_QUEUE_H_
#include <queue>
#include <mutex>
#include <condition_variable>
#include <initializer_list>
namespace queueSpace {
        /*
        * 线程安全队列
        * T为队列元素类型
        * 因为有std::mutex和std::condition_variable类成员,所以此类不支持复制构造函数也不支持赋值操作符(=)
        * */
        template<typename T>
        class threadsafe_queue{
        private:
            //data_queue访问信号量
            mutable std::mutex mut;
            mutable std::condition_variable data_cond;
            using queue_type = std::queue<T>;
            queue_type data_queue;
        public:
            using value_type = typename queue_type::value_type;
            using container_type = typename queue_type::container_type;
            threadsafe_queue() = default;
            threadsafe_queue(const threadsafe_queue&) = delete;
            threadsafe_queue& operator=(const threadsafe_queue&) = delete;
            /*
            * 使用迭代器为参数的构造函数,适用所有容器对象
            * */
            template<typename _InputIterator>
            threadsafe_queue(_InputIterator first, _InputIterator last){
                for (auto itor = first; itor != last; ++itor){
                    data_queue.push(*itor);
                }
            }
            explicit threadsafe_queue(const container_type &c) :data_queue(c){}
            /*
            * 使用初始化列表为参数的构造函数
            * */
            threadsafe_queue(std::initializer_list<value_type> list) :threadsafe_queue(list.begin(), list.end()){
            }
            /*
            * 将元素加入队列
            * */
            void push(const value_type &new_value){
                std::lock_guard<std::mutex>lk(mut);
                    data_queue.push(std::move(new_value));
                    data_cond.notify_one();
            }

            /*
            * 从队列中弹出一个元素,如果队列为空就阻塞
            * */
            value_type wait_and_pop(){
                std::unique_lock<std::mutex>lk(mut);
                data_cond.wait(lk, [this]{return !this->data_queue.empty(); });
                auto value = std::move(data_queue.front());
                data_queue.pop();
                return value;
            }
            /*
            * 从队列中弹出一个元素,如果队列为空返回false
            * */
            bool try_pop(value_type& value){
                std::lock_guard<std::mutex>lk(mut);
                if (data_queue.empty())
                    return false;
                value = std::move(data_queue.front());
                data_queue.pop();
                return true;
            }
            /*
            * 返回队列是否为空
            * */
            auto empty() const->decltype(data_queue.empty()) {
                std::lock_guard<std::mutex>lk(mut);
                return data_queue.empty();
            }
            /*
            * 返回队列中元素数个
            * */
            auto size() const->decltype(data_queue.size()){
                std::lock_guard<std::mutex>lk(mut);
                return data_queue.size();
            }
        }; /* threadsafe_queue */
}/* namespace queueSpace */
#endif /* COMMON_SOURCE_CPP_THREADSAFE_QUEUE_H_ */

 

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