async_tcp_echo_server.cpp 2.1 KB

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  1. //
  2. // async_tcp_echo_server.cpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
  6. //
  7. // Distributed under the Boost Software License, Version 1.0. (See accompanying
  8. // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  9. //
  10. #include <cstdlib>
  11. #include <iostream>
  12. #include <memory>
  13. #include <utility>
  14. #include <boost/asio.hpp>
  15. using boost::asio::ip::tcp;
  16. class session
  17. : public std::enable_shared_from_this<session>
  18. {
  19. public:
  20. session(tcp::socket socket)
  21. : socket_(std::move(socket))
  22. {
  23. }
  24. void start()
  25. {
  26. do_read();
  27. }
  28. private:
  29. void do_read()
  30. {
  31. auto self(shared_from_this());
  32. socket_.async_read_some(boost::asio::buffer(data_, max_length),
  33. [this, self](boost::system::error_code ec, std::size_t length)
  34. {
  35. if (!ec)
  36. {
  37. do_write(length);
  38. }
  39. });
  40. }
  41. void do_write(std::size_t length)
  42. {
  43. auto self(shared_from_this());
  44. boost::asio::async_write(socket_, boost::asio::buffer(data_, length),
  45. [this, self](boost::system::error_code ec, std::size_t /*length*/)
  46. {
  47. if (!ec)
  48. {
  49. do_read();
  50. }
  51. });
  52. }
  53. tcp::socket socket_;
  54. enum { max_length = 1024 };
  55. char data_[max_length];
  56. };
  57. class server
  58. {
  59. public:
  60. server(boost::asio::io_context& io_context, short port)
  61. : acceptor_(io_context, tcp::endpoint(tcp::v4(), port))
  62. {
  63. do_accept();
  64. }
  65. private:
  66. void do_accept()
  67. {
  68. acceptor_.async_accept(
  69. [this](boost::system::error_code ec, tcp::socket socket)
  70. {
  71. if (!ec)
  72. {
  73. std::make_shared<session>(std::move(socket))->start();
  74. }
  75. do_accept();
  76. });
  77. }
  78. tcp::acceptor acceptor_;
  79. };
  80. int main(int argc, char* argv[])
  81. {
  82. try
  83. {
  84. if (argc != 2)
  85. {
  86. std::cerr << "Usage: async_tcp_echo_server <port>\n";
  87. return 1;
  88. }
  89. boost::asio::io_context io_context;
  90. server s(io_context, std::atoi(argv[1]));
  91. io_context.run();
  92. }
  93. catch (std::exception& e)
  94. {
  95. std::cerr << "Exception: " << e.what() << "\n";
  96. }
  97. return 0;
  98. }