#include <iostream>
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/thread.hpp> 
using boost::asio::ip::tcp;
typedef boost::shared_ptr <tcp::socket> socket_ptr;
void client_session(socket_ptr);
int main()
{
 boost::asio::io_service io;
//Here is a simple synchronous server:using boost::asio;

tcp::endpoint ep( tcp::v4(), 2001); // listen on 2001
tcp::acceptor acc(io, ep);
while ( true) 
{
    socket_ptr sock(new tcp::socket(io));
    acc.accept(*sock);
    boost::thread (boost::bind(&client_session, sock));
    std::cout<<"Start thread"<<std::endl;
}
}
void client_session(socket_ptr sock)
{
while ( true)
{
  char data[512];
  size_t len = sock->read_some(boost::asio::buffer(data));
  if ( len > 0) 
      write(*sock, boost::asio::buffer("ok", 2));
}
}