(WebRTC : Example) Example Server main

int main(int argc, char* argv[]) {
  absl::SetProgramUsageMessage(
      "Example usage: ./peerconnection_server --port=8888\n");
  absl::ParseCommandLine(argc, argv);

  // InitFieldTrialsFromString stores the char*, so the char array must outlive
  // the application.
  const std::string force_field_trials = absl::GetFlag(FLAGS_force_fieldtrials);
  webrtc::field_trial::InitFieldTrialsFromString(force_field_trials.c_str());

  int port = absl::GetFlag(FLAGS_port);

  // Abort if the user specifies a port that is outside the allowed
  // range [1, 65535].
  if ((port < 1) || (port > 65535)) {
    printf("Error: %i is not a valid port.\n", port);
    return -1;
  }

  ListeningSocket listener;
  if (!listener.Create()) {
    printf("Failed to create server socket\n");
    return -1;
  } else if (!listener.Listen(port)) {
    printf("Failed to listen on server socket\n");
    return -1;
  }

  printf("Server listening on port %i\n", port);

  PeerChannel clients;
  typedef std::vector<DataSocket*> SocketArray;
  SocketArray sockets;
  bool quit = false;
  while (!quit) {
    fd_set socket_set;
    FD_ZERO(&socket_set);
    if (listener.valid())
      FD_SET(listener.socket(), &socket_set);

    for (SocketArray::iterator i = sockets.begin(); i != sockets.end(); ++i)
      FD_SET((*i)->socket(), &socket_set);

    struct timeval timeout = {10, 0};
    if (select(FD_SETSIZE, &socket_set, NULL, NULL, &timeout) == SOCKET_ERROR) {
      printf("select failed\n");
      break;
    }

    for (SocketArray::iterator i = sockets.begin(); i != sockets.end(); ++i) {
      DataSocket* s = *i;
      bool socket_done = true;
      if (FD_ISSET(s->socket(), &socket_set)) {
        if (s->OnDataAvailable(&socket_done) && s->request_received()) {
          ChannelMember* member = clients.Lookup(s);
          if (member || PeerChannel::IsPeerConnection(s)) {
            if (!member) {
              if (s->PathEquals("/sign_in")) {
                clients.AddMember(s);
              } else {
                printf("No member found for: %s\n", s->request_path().c_str());
                s->Send("500 Error", true, "text/plain", "",
                        "Peer most likely gone.");
              }
            } else if (member->is_wait_request(s)) {
              // no need to do anything.
              socket_done = false;
            } else {
              ChannelMember* target = clients.IsTargetedRequest(s);
              if (target) {
                member->ForwardRequestToPeer(s, target);
              } else if (s->PathEquals("/sign_out")) {
                s->Send("200 OK", true, "text/plain", "", "");
              } else {
                printf("Couldn't find target for request: %s\n",
                       s->request_path().c_str());
                s->Send("500 Error", true, "text/plain", "",
                        "Peer most likely gone.");
              }
            }
          } else {
            HandleBrowserRequest(s, &quit);
            if (quit) {
              printf("Quitting...\n");
              FD_CLR(listener.socket(), &socket_set);
              listener.Close();
              clients.CloseAll();
            }
          }
        }
      } else {
        socket_done = false;
      }

      if (socket_done) {
        printf("Disconnecting socket\n");
        clients.OnClosing(s);
        assert(s->valid());  // Close must not have been called yet.
        FD_CLR(s->socket(), &socket_set);
        delete (*i);
        i = sockets.erase(i);
        if (i == sockets.end())
          break;
      }
    }

    clients.CheckForTimeout();

    if (FD_ISSET(listener.socket(), &socket_set)) {
      DataSocket* s = listener.Accept();
      if (sockets.size() >= kMaxConnections) {
        delete s;  // sorry, that's all we can take.
        printf("Connection limit reached\n");
      } else {
        sockets.push_back(s);
        printf("New connection...\n");
      }
    }
  }

  for (SocketArray::iterator i = sockets.begin(); i != sockets.end(); ++i)
    delete (*i);
  sockets.clear();

  return 0;
}