Method handle_timer

example/cpp11/porthopper/server.cpp:120–145

Every time the timer fires we will generate a new frame and send it to all subscribers.

  // Every time the timer fires we will generate a new frame and send it to all
  // subscribers.
  void handle_timer()
  {
    // Generate payload.
    double x = next_frame_number_ * 0.2;
    double y = std::sin(x);
    int char_index = static_cast<int>((y + 1.0) * (frame::payload_size / 2));
    std::string payload;
    for (int i = 0; i < frame::payload_size; ++i)
      payload += (i == char_index ? '*' : '.');

    // Create the frame to be sent to all subscribers.
    frame f(next_frame_number_++, payload);

    // Send frame to all subscribers. We can use synchronous calls here since
    // UDP send operations typically do not block.
    std::set<udp::endpoint>::iterator j;
    for (j = subscribers_.begin(); j != subscribers_.end(); ++j)
    {
      boost::system::error_code ec;
      udp_socket_.send_to(f.to_buffers(), *j, 0, ec);
    }

    // Wait for next timeout.
    timer_.expires_after(boost::asio::chrono::milliseconds(100));
    timer_.async_wait(std::bind(&server::handle_timer, this));
  }

private:
  // The acceptor used to accept incoming control connections.