c++ non blocking thread for sockets

Question

I am new in the c++ programming and I have a question about threading. I have experienced in c# and java that; When you start a threading, it works independently and separates itself from the main thread. In other words child thread not blocks the main one.

However In c++ It seems that, it is not working in that way. When I use the join it blocks the code, when I use the detach it kills the thread.

I am using threading code sample for socket server thread, detach is killing the socket listening.

My aim, is to run the while looped listening socket independently and continuously run on the background. It shouldn't block the main thread flow.

How can be done? Is there a brief code sample for it.

I would be vey happy, if you help about this.

Here is my code below, I don't know what is wrong with it. I have to make: Thread has to run forever, It has to listen and answer.

#ifndef UNICODE
#define UNICODE 1
#endif

#pragma comment(lib, "Ws2_32.lib")
#include "soketSample.h"
    
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <ws2tcpip.h>
#include <winsock2.h>
//#include <MSWSock.h>
#include <share.h>
#include <atltypes.h>
#include <thread>





using namespace std;



string convertToString(char* a, int size)
{
    int i;
    string s = "";
    for (i = 0; i < size; i++) {
        s = s + a[i];
    }
    return s;
}



int socketSample() 
{
    WSADATA wsa;
    SOCKET s, new_socket;
    struct sockaddr_in server, client;
    int c;
    char *message, server_reply[2000];
    int recv_size;

    printf("\nInitialising Winsock...");
    if (WSAStartup(MAKEWORD(2, 2), &wsa) != 0)
    {
        printf("Failed. Error Code : %d", WSAGetLastError());
        return 1;
    }

    printf("Initialised.\n");

    //Create a socket
    if ((s = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
    {
        printf("Could not create socket : %d", WSAGetLastError());
    }


    printf("Socket created.\n");

    //Prepare the sockaddr_in structure
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY;
    server.sin_port = htons(30035);

    //Bind
    if (::bind(s, (struct sockaddr *)&server, sizeof(server)) == SOCKET_ERROR)
    {
        printf("Bind failed with error code : %d", WSAGetLastError());
    }

    puts("Bind done");

    

    //Listen to incoming connections
    listen(s, 3);

    //Accept and incoming connection
    puts("Waiting for incoming connections...");

    
    c = sizeof(struct sockaddr_in);
    new_socket = accept(s, (struct sockaddr*)&client, &c);
    if (new_socket == INVALID_SOCKET)
    {
        printf("accept failed with error code : %d", WSAGetLastError());
    }

    puts("Connection accepted");


    //Reply to client
    message = "Hello Client , Hello I will receive the connections from now on \n";
    send(new_socket, message, strlen(message), 0);


    //Declare and initialize variables.
    recv_size = 5;


    while (recv_size > 0)
    {
        recv_size = recv(new_socket, server_reply, 2000, 0);

        if (recv_size == 0 || recv_size == WSAECONNRESET)
        {
            printf("Client: Connection Closed.\n");
            break;
        }
        else
        {
            printf("Client: recv() is OK.\n");
            int server_reply_size = sizeof(server_reply);
            string result = convertToString(server_reply, server_reply_size);
            const char * k = result.c_str();
            //result = marshal_as<string>
            puts(k);
        }
        
                
    }


    puts("Data Send\n");
    getchar();

    closesocket(s);
    WSACleanup();

    return 0;
    
}

int main()
{
    std::thread thread_obj(socketSample);
    thread_obj.join();//if a I put join it blocks it.
    thread_obj.detach(); //in here detach kills my socket listen thread.
    puts("Thread is perfectly active..............");
    return 0;
}