function test2_threadpool()
    local tp = Dll.MyTHdPool()
    local n =1
    local function f()
        n = n+1
        print('f ' .. n)
        if(n==50) then return end
        tp:sleep1(0, f)
    end
    
    f()
    tp:join()
end

#include "stdafx.h"
#include <luabind.hpp>
#include <vector>
#include <queue>
#include <boost/thread.hpp>

using namespace luabind;

#include "stdafx.h"

#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/thread/thread.hpp>

#include <deque>

class ThreadPool
{
    boost::asio::io_service ioService;
    boost::thread_group threadpool;
    boost::asio::io_service::work work;
public:
    ThreadPool() :work(ioService)
    {
        /*
        * This will start the ioService processing loop. All tasks
        * assigned with ioService.post() will start executing.
        */
        //boost::asio::io_service::work work(ioService);

        /*
        * This will add 2 threads to the thread pool. (You could just put it in a for loop)
        */
        threadpool.create_thread(
            boost::bind(&boost::asio::io_service::run, &ioService)
            );
        threadpool.create_thread(
            boost::bind(&boost::asio::io_service::run, &ioService)
            );

    }
    ~ThreadPool()
    {

    }

    void post(boost::function<void()> f)
    {
        ioService.post(f);
    }

    void join()
    {
        threadpool.join_all();
    }
private:

};

namespace bamthread
{
    typedef std::unique_ptr<boost::asio::io_service::work> asio_worker;

    struct ThreadPool {
        ThreadPool(size_t threads) :service(), working(new asio_worker::element_type(service)) {
            while (threads--)
            {
                auto worker = boost::bind(&boost::asio::io_service::run, &(this->service));
                g.add_thread(new boost::thread(worker));
            }
        }

        template<class F>
        void post(F f){
            service.post(f);
        }

        ~ThreadPool() {
            working.reset(); //allow run() to exit
            g.join_all();
            service.stop();
        }

    private:
        boost::asio::io_service service; //< the io_service we are wrapping
        asio_worker working;
        boost::thread_group g; //< need to keep track of threads so we can join them
    };
}

void my_task()
{
    Sleep(1000);
    printf("mytask");
}

void test1()
{
    bamthread::ThreadPool tp(3);
    tp.post(boost::bind(my_task));
    //tp.join();
}

void test()
{
    /*
    * Create an asio::io_service and a thread_group (through pool in essence)
    */
    boost::asio::io_service ioService;
    boost::thread_group threadpool;


    /*
    * This will start the ioService processing loop. All tasks
    * assigned with ioService.post() will start executing.
    */
    boost::asio::io_service::work work(ioService);

    /*
    * This will add 2 threads to the thread pool. (You could just put it in a for loop)
    */
    threadpool.create_thread(
        boost::bind(&boost::asio::io_service::run, &ioService)
        );
    threadpool.create_thread(
        boost::bind(&boost::asio::io_service::run, &ioService)
        );

    /*
    * This will assign tasks to the thread pool.
    * More about boost::bind: "http://www.boost.org/doc/libs/1_54_0/libs/bind/bind.html#with_functions"
    */
    ioService.post(boost::bind(my_task));

    /*
    * This will stop the ioService processing loop. Any tasks
    * you add behind this point will not execute.
    */
    ioService.stop();

    /*
    * Will wait till all the threads in the thread pool are finished with
    * their assigned tasks and 'join' them. Just assume the threads inside
    * the threadpool will be destroyed by this method.
    */
    threadpool.join_all();
}


template <typename T>
class queue
{
private:
    boost::mutex              d_mutex;
    boost::condition_variable d_condition;
    std::deque<T>           d_queue;
public:
    void push(T const& value) {
        {
            boost::unique_lock<boost::mutex> lock(this->d_mutex);
            d_queue.push_front(value);
        }
        this->d_condition.notify_one();
    }
    T pop() {
        boost::unique_lock<boost::mutex> lock(this->d_mutex);
        this->d_condition.wait(lock, [=]{ return !this->d_queue.empty(); });
        T rc(std::move(this->d_queue.back()));
        this->d_queue.pop_back();
        return rc;
    }
};

class MyTHdPool
{
    bamthread::ThreadPool tp;

    boost::mutex m;
    std::map<int, boost::function<void()> > f2s;    // key: taskid, value: post processing
    
    //boost::thread t_;

    queue<int> q_;
    int taskid_;

public:
    MyTHdPool() :tp(3), taskid_(0){}

    ~MyTHdPool(){
        join();
    }

    void Call(boost::function<void()> f1, boost::function<void()> f2)
    {
        int taskid = taskid_++;

        printf("begin call task %d\n", taskid);

        boost::function<void()> f = [=]() mutable {
            f1();

            q_.push(taskid);
            printf("done task %d\n", taskid);
        };

        {
            boost::lock_guard<boost::mutex> lock(m);
            f2s[taskid] = (f2);
        }

        tp.post(f);
        printf("end post task %d\n", taskid);
    }

    void join()
    {
        while (true)
        {
            boost::function<void()> f2;
            int taskid = 0;
            {
                {
                    boost::lock_guard<boost::mutex> lock(m);
                    if (f2s.empty())
                        return;
                }

                printf("start pop a task from queue\n");
                int taskid = q_.pop();
                printf("got a task %d from queue\n", taskid);

                {
                    boost::lock_guard<boost::mutex> lock(m);
                    auto it = f2s.find(taskid);
                    assert(it != f2s.end());
                    f2 = it->second;
                    f2s.erase(it);
                }
            }

            printf("exec task post ftn %d\n", taskid);
            f2();
        }
    }

    void sleep1(double n, object f2)
    {
        Call([n](){Sleep(n * 1000); }, [f2, this]() mutable {
            f2(); 
        });
    }

    void sleep2(double n)
    {
        Call([n](){Sleep(n * 1000); }, [](){});
    }
private:

};

void callback(object o)
{
    printf("before callback\n");
    o();
    printf("after callback\n");
}

int luaopen_Dll(lua_State* L)
{
    
    luaL_openlibs(L);
    open(L);

    // define a module in _G["t"]
    module(L, "Dll")[
        

        class_<MyTHdPool>("MyTHdPool")
        .def(constructor<>())
        .def("sleep1", &MyTHdPool::sleep1)
        .def("sleep2", &MyTHdPool::sleep2)
        .def("join", &MyTHdPool::join),

        def("test1", &test1),

        def("callback", &callback)
    ];

    // push _G["t"] to stack
    lua_getglobal(L, "Dll");

    // set _G["t"]=nil
    lua_pushnil(L);
    lua_setglobal(L, "Dll");

    return 1;
}