将boost-asio与KDB+基于文件描述符的套接字api集成

Question

我对boost-asio比较陌生，我想知道是否有可能让它与KDB+ api here一起工作。

我尝试了下面这样的方法，但似乎不能正常工作。

#include <iostream>
#include <string>
#include <boost/asio.hpp>
#include <boost/bind.hpp>

#define KXVER 3

#include "kx/k.h"

using boost::asio::ip::tcp;
namespace posix = boost::asio::posix;

class Feedhandler
{
public:
    Feedhandler(boost::asio::io_service &io_service) : m_qsvc(io_service) {

        char host[] = "localhost";
        int port = 6812;

        m_fd = khpu(host, port, "user:pass");
        m_qsvc.assign(m_fd);

        start_operations();

        K ret = k(m_fd, ".u.sub", ks(""), ks(""), (K)0);

    }

    void start_operations()
    {
        boost::asio::async_read(m_qsvc, boost::asio::null_buffers(),
                                boost::bind(&Feedhandler::handle_read, this, boost::asio::placeholders::error,
                                            boost::asio::placeholders::bytes_transferred));

    }

    void handle_read(const boost::system::error_code& error, size_t size)
    {
        K data = k(m_fd,(S)0);
        start_operations();
    }


private:
    int m_fd;
    posix::stream_descriptor m_qsvc;

};

int main(int argc, char* argv[])
{

    boost::asio::io_service io_service;

    Feedhandler fh(io_service);

    io_service.run();

    return 0;
}

handle_read方法被调用一次，然后就不再有回调了。

Answer 1

实际上，最好使用async_wait而不是async_read，如下所示：

m_qsvc.async_wait(boost::asio::posix::stream_descriptor::wait_read, 
   boost::bind(&Feedhandler::handle_read, this, boost::asio::placeholders::error) );