Boost asio, single TCP server, many clients

Question

I am creating a TCP server that will use boost asio which will accept connections from many clients, receive data, and send confirmations. The thing is that I want to be abl

Answer 1

The includes you need. Some maybe are unnecessary:

boost/asio.hpp, boost/thread.hpp, boost/asio/io_service.hpp

boost/asio/spawn.hpp, boost/asio/write.hpp, boost/asio/buffer.hpp

boost/asio/ip/tcp.hpp, iostream, stdlib.h, array, string

vector, string.h, stdio.h, process.h, iterator

using namespace boost::asio;
using namespace boost::asio::ip;

io_service ioservice;

tcp::endpoint sim_endpoint{ tcp::v4(), 4066 };              //{which connectiontype, portnumber}
tcp::acceptor sim_acceptor{ ioservice, sim_endpoint };
std::vector sim_sockets;

static int iErgebnis;
int iSocket = 0;


void do_write(int a)                                        //int a is the postion of the socket in the vector
{
    int iWSchleife = 1;                                     //to stay connected with putty or something
    static char chData[32000];
    std::string sBuf = "Received!\r\n";

    while (iWSchleife > 0)          
    {
        boost::system::error_code error;
        memset(chData, 0, sizeof(chData));        //clear the char 

        iErgebnis = sim_sockets[a].read_some(boost::asio::buffer(chData), error);           //recv data from client
        iWSchleife = iErgebnis;                                                             //if iErgebnis is bigger then 0 it will stay in the loop. iErgebniss is always >0 when data is received

        if (iErgebnis > 0) {
            printf("%d data received from client : \n%s\n\n", iErgebnis, chData);
            write(sim_sockets[a], boost::asio::buffer(sBuf), error);  //send data to client
        }
        else {
            boost::system::error_code ec;
            sim_sockets[a].shutdown(boost::asio::ip::tcp::socket::shutdown_send, ec);       //close the socket when no data
            if (ec)
            {
                printf("studown error");                                                    // An error occurred.
            }
        }
    }
}

void do_accept(yield_context yield)
{
    while (1)                                                   //endless loop to accept limitless clients
    {
        sim_sockets.emplace_back(ioservice);                    //look to the link below for more info
        sim_acceptor.async_accept(sim_sockets.back(), yield);   //waits here to accept an client

        boost::thread dosome(do_write, iSocket);                //when accepted, starts the thread do_write and passes the parameter iSocket
        iSocket++;                                              //to know the position of the socket in the vector

    }
}

int main()
{
    sim_acceptor.listen();
    spawn(ioservice, do_accept);            //here you can learn more about Coroutines https://theboostcpplibraries.com/boost.coroutine
    ioservice.run();                        //from here you jump to do:accept
    getchar(); 
}