Socket FD + Select

#include <stdio.h>
#include <sys/select.h>
#include <sys/time.h>
#include <vector>

#include <error.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

using namespace std;

//-----------------------------------------
int createServer_FD( int portno ) {

        int sockfd = socket(AF_INET, SOCK_STREAM, 0);
        if (sockfd < 0) {
                perror("ERROR opening socket");
        }

        struct sockaddr_in serv_addr;

        bzero((char *) &serv_addr, sizeof(serv_addr));
        serv_addr.sin_family = AF_INET;
        serv_addr.sin_addr.s_addr = INADDR_ANY;
        serv_addr.sin_port = htons(portno);
        if ( bind( sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
              perror("ERROR on binding");
        }
        listen(sockfd,5);
        return sockfd;
}


//---------------------------------------
int main() {

        fd_set                  readfds;
        struct timeval          tmTimeout;
        tmTimeout.tv_sec = 0;
        tmTimeout.tv_usec = 500000;
        char buffer[1024];

        int server_fd = createServer_FD(10000);
        vector <int> client_list;

        printf("Sock server fd: %d ready, Entering Loop...\n", server_fd );

        for (;;) {
                FD_ZERO(&readfds);
                FD_SET( server_fd , &readfds);
                for ( int i = 0 ; i < client_list.size() ; i++ ) {
                        FD_SET( client_list[i] , &readfds);
                }

                int readsocks = select( server_fd + 1 +  client_list.size() , &readfds, (fd_set*)0, (fd_set*)0, &tmTimeout);
                if ( readsocks == -1 ) {
                        perror("Socket Error");
                }

                if ( readsocks == 0) {
                        /* Nothing ready to read, just show that
                           we're alive */
                } else {

                        // The sock server is in one of the ISSET in ReadSet
                        // This means it receives some connection request.
                        if ( FD_ISSET( server_fd, &readfds )) {

                                // Accept the client's connection request 
                                printf( "Incoming Connection...\n");
                                int connection = accept( server_fd, NULL, NULL);
                                if (connection == -1) {
                                        perror("Accept error: Invalid socket!");
                                } else {
                                        printf("Connection accepted. Client fd %d\n", connection);
                                        client_list.push_back( connection );
                                }
                        }

                        for ( int i = 0 ; i < client_list.size() ; i++ ) {
                            if ( FD_ISSET( client_list[i] , &readfds ) ) {

                                // If it is , read and print
                                int n = recv( client_list[i], buffer, 1024, 0 );
                                buffer[n] = 0;
                                printf("Received: %s", buffer) ;
                            }
                        }
                }

                //svc_getreqset( &readfds );
        }
}