C++11 半同步半异步线程池的实现

#include <list>
#include <mutex>
#include <thread>
#include <condition_variable>
#include <iostream>
#include <functional>
#include <memory>
#include <atomic>
using namespace std;

namespace itstation 
{
    template<typename T>
    class SynaQueue
    {
    public:
        SynaQueue(int maxSize)
            :m_maxSize(maxSize), m_needStop(false)
        {
        }

        void Put(const T& x)
        {
            Add(x);
        }
        void Put(T&& x)
        {
            Add(forward<T>(x)); //完美转发,不改变参数的类型
        }
        void Take(list<T>& list)
        {
            std::unique_lock<mutex> locker(m_mutex);
            // 判断式, 当都不满足条件时,条件变量会释放mutex, 并将线程置于waiting状态, 等待其他线程调用notify_one/all 将其唤醒。
            // 当满足其中一个条件时继续执行, 将队列中的任务取出,唤醒等待添加任务的线程
            // 当处于waiting状态的线程被唤醒时,先获取mutex,检查条件是否满足,满足-继续执行,否则释放mutex继续等待
            m_notEmpty.wait(locker, [this]{return m_needStop || NotEmpty(); });
            if (m_needStop)
                return;
            list = move(m_queue);
            m_notFull.notify_one();
        }
        void Take(T& t)
        {
            unique_lock<mutex> locker(m_mutex); //
            m_notEmpty.wait(locker, [this]{return m_needStop || NotEmpty(); });
            if (m_needStop)
                return;
            t = m_queue.front();
            m_queue.pop_front();
            m_notFull.notify_one();
        }
        void Stop()
        {
            {
                lock_guard<mutex> locker(m_mutex);
                m_needStop = true;
            }
            m_notFull.notify_all(); // 将所有等待的线程全部唤醒,被唤醒的进程检查m_needStop,为真,所有的线程退出执行
            m_notEmpty.notify_all();
        }

    private:
        bool NotFull() const
        {
            bool full = m_queue.size() >= m_maxSize;
            if (full)
                cout << "缓冲区满了,需要等待。。。。" << endl;
            return !full;
        }
        bool NotEmpty() const
        {
            bool empty = m_queue.empty();
            if (empty)
                cout << "缓冲区空了,需要等待,。。。异步层线程: " << this_thread::get_id() << endl;
            return !empty;
        }


        template<typename F>
        void Add(F&& x)
        {
            unique_lock<mutex> locker(m_mutex); // 通过m_mutex获得写锁
            m_notFull.wait(locker, [this]{return m_needStop || NotFull(); }); // 没有停止且满了,就释放m_mutex并waiting;有一个为真就继续执行
            if (m_needStop)
                return;
            m_queue.push_back(forward<F>(x));
            m_notEmpty.notify_one();
        }


    private:
        list<T> m_queue; //缓冲区
        mutex m_mutex;  // 互斥量
        condition_variable m_notEmpty; // 条件变量
        condition_variable m_notFull;
        int m_maxSize; //同步队列最大的size
        bool m_needStop; // 停止标识
    };

    const int MaxTaskCount = 100;
    class ThreadPool
    {
    public:
        using Task = function < void() >;
        ThreadPool(int numThread = thread::hardware_concurrency())
            :m_queue(MaxTaskCount)
        {
            Start(numThread);
        }

        virtual ~ThreadPool()
        {
            Stop();
        }

        void Stop()
        {
            call_once(m_flag, [this]{StopThreadGroup(); });
        }

        void AddTask(Task&& task)
        {
            m_queue.Put(forward<Task>(task));
        }

        void AddTask(const Task& task)
        {
            m_queue.Put(task);
        }

    private:
        void Start(int numThreads)
        {
            m_running = true;
            //创建线程组
            for (int i = 0; i < numThreads; i++)
            {
                m_threadgroup.emplace_back(make_shared<thread>(&ThreadPool::RunInThread, this));
            }
        }

        // 每个线程都执行这个函数
        void RunInThread()
        {
            while (m_running)
            {
                //取任务分别执行
                list<Task> list;
                m_queue.Take(list);
                for (auto& task : list)
                {
                    if (!m_running)
                        return;

                    task();
                }
            }
        }
        void StopThreadGroup()
        {
            m_queue.Stop(); // 同步队列中的线程停止
            m_running = false; // 让内部线程跳出循环并推出
            for (auto thread : m_threadgroup)
            {
                if (thread)
                    thread->join();
            }
            m_threadgroup.clear();
        }
    private:
        list<shared_ptr<thread>> m_threadgroup; // 处理任务的线程组, 链表中存储着指向线程的共享指针
        SynaQueue<Task> m_queue; //同步队列
        atomic_bool m_running; // 是否停止的标识
        once_flag m_flag;
    };
} // namespace itstation 

#include <stdio.h>
#include <iostream>
#include "ObjectPool.h"
#include <list>
using namespace std;
using namespace itstation;


void TestThreadPool()
{
    ThreadPool pool(2);
    thread thd1([&pool]{
        for (int i = 0; i < 10; i++)
        {
            auto thrID = this_thread::get_id();
            pool.AddTask([thrID, i]{cout << "同步层线程1的线程ID:" << thrID << "  这是任务 " << i << endl; this_thread::sleep_for(chrono::seconds(2)); });
        }
    });

    thread thd2([&pool]{
        for (int i = 0; i < 10; i++)
        {
            auto thrID = this_thread::get_id();
            pool.AddTask([thrID, i]{cout << "同步层线程2的线程ID:" << thrID << "  这是任务 " << i << endl; this_thread::sleep_for(chrono::seconds(2)); });
        }
    });

    this_thread::sleep_for(chrono::seconds(45));
    pool.Stop();
    thd1.join();
    thd2.join();
}
int main()
{
    TestThreadPool();



    getchar();
    return 0;
}
原文地址:https://www.cnblogs.com/kaishan1990/p/5273237.html