C++ - Thread for socket server
<p>I'm trying to implement a server, which runs in his own thread.
Later, the server should work together with another thread.
Is that even possible?</p>

<p>My current attempt to implement this:</p>

<p>main</p>

<pre><code>#include "EtherServer.h"

int main(int argc, char *argv[])
{
    EtherServer* es = new EtherServer();
    es-&gt;init();
    return 0;
}
</code></pre>

<p>Server.h</p>

<pre><code>#include &lt;stdio.h&gt;
#include &lt;stdlib.h&gt;
#include &lt;unistd.h&gt;
#include &lt;errno.h&gt;
#include &lt;string.h&gt;
#include &lt;sys/types.h&gt;
#include &lt;sys/socket.h&gt;
#include &lt;netinet/in.h&gt;
#include &lt;netdb.h&gt;
#include &lt;arpa/inet.h&gt;
#include &lt;sys/wait.h&gt;
#include &lt;signal.h&gt;
#include &lt;pthread.h&gt;

#ifndef ETHERSERVER_H_
#define ETHERSERVER_H_

class EtherServer
{
    public:
        bool init();
        static void* runServer(void *arg);
        static void sigchld_handler(int s);
        static void* get_in_addr(struct sockaddr *sa);

        static int s_sockfd;

    private:

};

#endif /* ETHERSERVER_H_ */
</code></pre>

<p>Server.cpp</p>

<pre><code>#include "EtherServer.h"

#define PORT "31107"  // the port users will be connecting to

#define BACKLOG 10     // how many pending connections queue will hold

int EtherServer::s_sockfd = 0;

void EtherServer::sigchld_handler(int s)
{
    // waitpid() might overwrite errno, so we save and restore it:
    int saved_errno = errno;

    while(waitpid(-1, NULL, WNOHANG) &gt; 0);

    errno = saved_errno;
}


// get sockaddr, IPv4 or IPv6:
void* EtherServer::get_in_addr(struct sockaddr *sa)
{
    if (sa-&gt;sa_family == AF_INET) {
        return &amp;(((struct sockaddr_in*)sa)-&gt;sin_addr);
    }

    return &amp;(((struct sockaddr_in6*)sa)-&gt;sin6_addr);
}

bool EtherServer::init()
{
    int rv;
    int yes=1;
    struct addrinfo hints, *servinfo, *p;

    memset(&amp;hints, 0, sizeof hints);
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags = AI_PASSIVE; // use my IP
    if ((rv = getaddrinfo(NULL, PORT, &amp;hints, &amp;servinfo)) != 0) {
        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
    }

    // loop through all the results and bind to the first we can
    for(p = servinfo; p != NULL; p = p-&gt;ai_next)
    {
        if ((EtherServer::s_sockfd = socket(p-&gt;ai_family, p-&gt;ai_socktype,
                p-&gt;ai_protocol)) == -1) {
            perror("server: socket");
            continue;
        }

        if (setsockopt(EtherServer::s_sockfd, SOL_SOCKET, SO_REUSEADDR, yes,                      
            sizeof(int)) == -1) 
        {
            perror("setsockopt");
            exit(1);
        }

        if (bind(EtherServer::s_sockfd, p-&gt;ai_addr, p-&gt;ai_addrlen) == -1) 
        {
            close(EtherServer::s_sockfd);
            perror("server: bind");
            continue;
        }

        break;
    }

    freeaddrinfo(servinfo); // all done with this structure
    if (p == NULL)  {
        fprintf(stderr, "server: failed to bind\n");
        exit(1);

    }

    if (listen(EtherServer::s_sockfd, BACKLOG) == -1) {
        perror("listen");
        exit(1);
    }

    struct sigaction sa;

    sa.sa_handler = EtherServer::sigchld_handler;
    sigemptyset(&amp;sa.sa_mask);
    sa.sa_flags = 0;
    if (sigaction(SIGCHLD, &amp;sa, NULL) == -1) {
        perror("sigaction");
        exit(1);
    }

    pthread_attr_t attr_baseb;
    (void)pthread_attr_init(&amp;attr_baseb);
    (void)pthread_attr_setdetachstate(&amp;attr_baseb, PTHREAD_CREATE_DETACHED);
    (void)pthread_create(NULL, &amp;attr_baseb, &amp;runServer, (void *)this);
}

void* EtherServer::runServer(void *arg)
{
    int new_fd;  // listen on sock_fd, new connection on new_fd
    //struct addrinfo hints, *servinfo, *p;
    struct sockaddr_storage their_addr; // connector's address information
    socklen_t sin_size;
    char s[INET6_ADDRSTRLEN];

    printf("server: waiting for connections...\n");

    while(1) {  // main accept() loop
        sin_size = sizeof their_addr;
        sleep(1);
        new_fd = accept(EtherServer::s_sockfd, (struct sockaddr *)&amp;their_addr, &amp;sin_size);
        if (new_fd == -1) {
            perror("accept");
            continue;
        }

        inet_ntop(their_addr.ss_family, EtherServer::get_in_addr((struct sockaddr *)&amp;their_addr), s, sizeof s);
        printf("server: got connection from %s\n", s);

        if (!fork()) { // this is the child process
            int n;
            char buffer[256];
            bzero(buffer, 256);
            close(EtherServer::s_sockfd); // child doesn't need the listener

            while (n = read(new_fd, buffer, 255) &gt; 0)
            {

                if (send(new_fd, buffer, 255, 0) == -1)
                    perror("send");
            }
            close(new_fd);
            exit(0);
            sleep(1);
        }
        close(new_fd);  // parent doesn't need this
    }
}
</code></pre>