asio/src/examples/cpp11/multicast/sender.cpp

//
// sender.cpp
// ~~~~~~~~~~
//
// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#include <iostream>
#include <sstream>
#include <string>
#include "asio.hpp"

constexpr short multicast_port = 30001;
constexpr int max_message_count = 10;

class sender
{
public:
  sender(asio::io_context& io_context,
      const asio::ip::address& multicast_address)
    : endpoint_(multicast_address, multicast_port),
      socket_(io_context, endpoint_.protocol()),
      timer_(io_context),
      message_count_(0)
  {
    do_send();
  }

private:
  void do_send()
  {
    std::ostringstream os;
    os << "Message " << message_count_++;
    message_ = os.str();

    socket_.async_send_to(
        asio::buffer(message_), endpoint_,
        [this](std::error_code ec, std::size_t /*length*/)
        {
          if (!ec && message_count_ < max_message_count)
            do_timeout();
        });
  }

  void do_timeout()
  {
    timer_.expires_after(std::chrono::seconds(1));
    timer_.async_wait(
        [this](std::error_code ec)
        {
          if (!ec)
            do_send();
        });
  }

private:
  asio::ip::udp::endpoint endpoint_;
  asio::ip::udp::socket socket_;
  asio::steady_timer timer_;
  int message_count_;
  std::string message_;
};

int main(int argc, char* argv[])
{
  try
  {
    if (argc != 2)
    {
      std::cerr << "Usage: sender <multicast_address>\n";
      std::cerr << "  For IPv4, try:\n";
      std::cerr << "    sender 239.255.0.1\n";
      std::cerr << "  For IPv6, try:\n";
      std::cerr << "    sender ff31::8000:1234\n";
      return 1;
    }

    asio::io_context io_context;
    sender s(io_context, asio::ip::make_address(argv[1]));
    io_context.run();
  }
  catch (std::exception& e)
  {
    std::cerr << "Exception: " << e.what() << "\n";
  }

  return 0;
}