C++实现一个简单消息队列的示例详解

void push(const T& msg);    

//等待消息
void wait(T& msg);

bool poll(T& msg);

#include<queue>
std::queue<T> _queue;

#include<mutex>
std::mutex _mtx;

#include<condition_variable>
std::condition_variable _cv;

#include<mutex>
#include<condition_variable>
#include<queue>
/// <summary>
/// 消息队列
/// </summary>
/// <typeparam name="T">消息类型</typeparam>
template<class T> class MessageQueue {
public:
    /// <summary>
    /// 推入消息
    /// </summary>
    /// <param name="msg">消息对象</param>
    void push(const T& msg) {
        std::unique_lock<std::mutex>lck(_mtx);
        _queue.push(msg);
        _cv.notify_one();
    }
    /// <summary>
    /// 轮询消息
    /// </summary>
    /// <param name="msg">消息对象</param>
    /// <returns>是否接收到消息</returns>
    bool poll(T& msg) {
        std::unique_lock<std::mutex>lck(_mtx);
        if (_queue.size())
        {
            msg = _queue.front();
            _queue.pop();
            return true;
        }
        return false;
    }
    /// <summary>
    /// 等待消息
    /// </summary>
    /// <param name="msg">消息对象</param>
    void wait(T& msg) {
        std::unique_lock<std::mutex>lck(_mtx);
        while (!_queue.size()) _cv.wait(lck);
        msg = _queue.front();
        _queue.pop();
    }
    //队列长度
    size_t size() {
        std::unique_lock<std::mutex>lck(_mtx);
        return _queue.size();
    }
private:
    //队列
    std::queue<T> _queue;
    //互斥变量
    std::mutex _mtx;
    //条件变量
    std::condition_variable _cv;
};

#include<thread>
//自定义消息对象
class MyMessage {
public:
    int type;
    void* param1;
    void* param2;
};
int main(int argc, char* argv[])
{
    //初始化消息队列
    MessageQueue<MyMessage> mq;
    //启动线程
    std::thread t1([&]() {
        MyMessage msg;
        while (1) {
            //等待队列的消息
            mq.wait(msg);
            printf("receive message type:%d\n", msg.type);
            if (msg.type == 1001)
                break;
        }
        printf("thread exited\n");
        });
    //发送消息给线程
    MyMessage msg;
    printf("send number message to thread.1001 exit\n");
    while (1)
    {
        scanf("%d", &msg.type);
        mq.push(msg);
        if (msg.type == 1001)
            break;
    }
    t1.join();
    return 0;
}

#include<thread>
//自定义消息对象
class MyMessage {
public:
    int type;
    void* param1;
    void* param2;
};
int main(int argc, char* argv[])
{
    //初始化消息队列
    MessageQueue<MyMessage> mq;
    //启动线程
    std::thread t1([&]() {
        MyMessage msg;
        while (1) {
            //轮询队列的消息
            if (mq.poll(msg))
            {
                printf("receive message type:%d\n", msg.type);
                if (msg.type == 1001)
                    break;
            }
            std::this_thread::sleep_for(std::chrono::milliseconds(10));
        }
        printf("thread exited\n");
        });
    //发送消息给线程
    MyMessage msg;
    printf("send number message to thread.1001 exit\n");
    while (1)
    {
        scanf("%d", &msg.type);
        mq.push(msg);
        if (msg.type == 1001)
            break;
    }
    t1.join();
    return 0;
}