Do i need boost strand - c++11

Question

I modified echo example but I have issues understanding boost strand.
Do I need or not?
I yes please be kind and give code for.
I searched examples but I can not understand (Im just stupid..)
Thank you
#include <cstdlib>
#include <iostream>
#include <memory>
#include <utility>
#include <boost/asio.hpp>
#include <boost/thread.hpp>
#include "mingw.thread.h"
#include <boost/bind.hpp>
class session
: public std::enable_shared_from_this<session>
{
public:
session(boost::asio::ip::tcp::socket socket)
: socket_(std::move(socket))
{
}
void start()
{
input_buffer_str = "[2J[H[A\r\n*ServerV8*\r\nSCAN_BADGE:\r\n";
out_msg =input_buffer_str;
do_write(out_msg.length());
}
private:
void do_read()
{
// std::cout << "do_read" <<"" <<std::endl;
auto self(shared_from_this());
//async_read_until for Telnet client
async_read_until(socket_,input_buffer_,'\r',
[this, self](boost::system::error_code ec, std::size_t length)
{
if (!ec)
{
do_write(length);
}
else
{
// std::cout<<ec <<"Disconection?"<<std::endl;
input_buffer_str.clear();
out_msg.clear();
input_buffer_.consume(length);
// Some Cleanup
}
});
}
// async_write back to Telnet client based on received
// will be result on SQL Query
void do_write(std::size_t length)
{
auto self(shared_from_this());
std::istream(&input_buffer_) >> input_buffer_str;
input_buffer_.consume(length);
std::cout << input_buffer_str <<std::endl;
if (input_buffer_str == "c") close();
if (input_buffer_str == "a") out_msg = "test_a\r\n";
if (input_buffer_str == "t")
{
Sleep(30000);
out_msg = "test_t\r\n";
}
if(input_buffer_str.length()>0 && out_msg.length()>0)
{
input_buffer_str.clear();
boost::asio::async_write(socket_, boost::asio::buffer(out_msg, out_msg.length()),
[this, self](boost::system::error_code ec, std::size_t length)
{
if (!ec) do_read();
else
{
out_msg.clear();
input_buffer_.consume(length);
// Some Cleanup
}
out_msg.clear();
});
}else do_read();
}
// close() Telnet client will be when user pushes F2 (Handheld scanner)
void close()
{
std::cout <<"Closing..."<<std::endl;
boost::system::error_code ec;
input_buffer_str.clear();
out_msg.clear();
socket_.shutdown(boost::asio::ip::tcp::socket::shutdown_both);
Sleep(250);
socket_.close(ec);
// delete data_;
if (ec)
{
std::cout<<ec << std::endl;
// An error occurred.
}
std::cout <<"Closed..."<<std::endl;
}
boost::asio::streambuf input_buffer_;
std::string input_buffer_str;
std::string out_msg ;
boost::asio::ip::tcp::socket socket_;
//enum { max_length = 1024 };
//char data_[max_length];
//std::string ClearScreen= "[2J[H[A"; "\r\n*ServerV8*\r\nSCAN_BADGE:\r\n";
};
Copy paste from example
class server
{
public:
server(boost::asio::io_context& io_context, short port)
: acceptor_(io_context, boost::asio::ip::tcp::endpoint(boost::asio::ip::tcp::v4(), port))
{
do_accept();
}
private:
void do_accept()
{
acceptor_.async_accept(
[this](boost::system::error_code ec, boost::asio::ip::tcp::socket socket)
{
if (!ec)
{
std::make_shared<session>(std::move(socket))->start();
}
do_accept();
});
}
boost::asio::ip::tcp::acceptor acceptor_;
};
added Threads Some queries to sql might take depends on Network
int main(int argc, char* argv[])
{
auto thread_count = std::thread::hardware_concurrency(); // for multi core
boost::thread_group m_Threads;
boost::asio::io_context m_io_context;
server srv(m_io_context, 23);
for(unsigned int i = 0; i < thread_count; ++i)
m_Threads.create_thread( [&](){m_io_context.run();});
m_Threads.join_all();
return 0;
}