select_reactor.hpp 8.6 KB

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  1. //
  2. // detail/select_reactor.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2021 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. #ifndef BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP
  11. #define BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP
  12. #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  13. # pragma once
  14. #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  15. #include <boost/asio/detail/config.hpp>
  16. #if defined(BOOST_ASIO_HAS_IOCP) \
  17. || (!defined(BOOST_ASIO_HAS_DEV_POLL) \
  18. && !defined(BOOST_ASIO_HAS_EPOLL) \
  19. && !defined(BOOST_ASIO_HAS_KQUEUE) \
  20. && !defined(BOOST_ASIO_WINDOWS_RUNTIME))
  21. #include <cstddef>
  22. #include <boost/asio/detail/fd_set_adapter.hpp>
  23. #include <boost/asio/detail/limits.hpp>
  24. #include <boost/asio/detail/mutex.hpp>
  25. #include <boost/asio/detail/op_queue.hpp>
  26. #include <boost/asio/detail/reactor_op.hpp>
  27. #include <boost/asio/detail/reactor_op_queue.hpp>
  28. #include <boost/asio/detail/select_interrupter.hpp>
  29. #include <boost/asio/detail/socket_types.hpp>
  30. #include <boost/asio/detail/timer_queue_base.hpp>
  31. #include <boost/asio/detail/timer_queue_set.hpp>
  32. #include <boost/asio/detail/wait_op.hpp>
  33. #include <boost/asio/execution_context.hpp>
  34. #if defined(BOOST_ASIO_HAS_IOCP)
  35. # include <boost/asio/detail/thread.hpp>
  36. #endif // defined(BOOST_ASIO_HAS_IOCP)
  37. #include <boost/asio/detail/push_options.hpp>
  38. namespace boost {
  39. namespace asio {
  40. namespace detail {
  41. class select_reactor
  42. : public execution_context_service_base<select_reactor>
  43. {
  44. public:
  45. #if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  46. enum op_types { read_op = 0, write_op = 1, except_op = 2,
  47. max_select_ops = 3, connect_op = 3, max_ops = 4 };
  48. #else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  49. enum op_types { read_op = 0, write_op = 1, except_op = 2,
  50. max_select_ops = 3, connect_op = 1, max_ops = 3 };
  51. #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  52. // Per-descriptor data.
  53. struct per_descriptor_data
  54. {
  55. };
  56. // Constructor.
  57. BOOST_ASIO_DECL select_reactor(boost::asio::execution_context& ctx);
  58. // Destructor.
  59. BOOST_ASIO_DECL ~select_reactor();
  60. // Destroy all user-defined handler objects owned by the service.
  61. BOOST_ASIO_DECL void shutdown();
  62. // Recreate internal descriptors following a fork.
  63. BOOST_ASIO_DECL void notify_fork(
  64. boost::asio::execution_context::fork_event fork_ev);
  65. // Initialise the task, but only if the reactor is not in its own thread.
  66. BOOST_ASIO_DECL void init_task();
  67. // Register a socket with the reactor. Returns 0 on success, system error
  68. // code on failure.
  69. BOOST_ASIO_DECL int register_descriptor(socket_type, per_descriptor_data&);
  70. // Register a descriptor with an associated single operation. Returns 0 on
  71. // success, system error code on failure.
  72. BOOST_ASIO_DECL int register_internal_descriptor(
  73. int op_type, socket_type descriptor,
  74. per_descriptor_data& descriptor_data, reactor_op* op);
  75. // Post a reactor operation for immediate completion.
  76. void post_immediate_completion(reactor_op* op, bool is_continuation)
  77. {
  78. scheduler_.post_immediate_completion(op, is_continuation);
  79. }
  80. // Start a new operation. The reactor operation will be performed when the
  81. // given descriptor is flagged as ready, or an error has occurred.
  82. BOOST_ASIO_DECL void start_op(int op_type, socket_type descriptor,
  83. per_descriptor_data&, reactor_op* op, bool is_continuation, bool);
  84. // Cancel all operations associated with the given descriptor. The
  85. // handlers associated with the descriptor will be invoked with the
  86. // operation_aborted error.
  87. BOOST_ASIO_DECL void cancel_ops(socket_type descriptor, per_descriptor_data&);
  88. // Cancel any operations that are running against the descriptor and remove
  89. // its registration from the reactor. The reactor resources associated with
  90. // the descriptor must be released by calling cleanup_descriptor_data.
  91. BOOST_ASIO_DECL void deregister_descriptor(socket_type descriptor,
  92. per_descriptor_data&, bool closing);
  93. // Remove the descriptor's registration from the reactor. The reactor
  94. // resources associated with the descriptor must be released by calling
  95. // cleanup_descriptor_data.
  96. BOOST_ASIO_DECL void deregister_internal_descriptor(
  97. socket_type descriptor, per_descriptor_data&);
  98. // Perform any post-deregistration cleanup tasks associated with the
  99. // descriptor data.
  100. BOOST_ASIO_DECL void cleanup_descriptor_data(per_descriptor_data&);
  101. // Move descriptor registration from one descriptor_data object to another.
  102. BOOST_ASIO_DECL void move_descriptor(socket_type descriptor,
  103. per_descriptor_data& target_descriptor_data,
  104. per_descriptor_data& source_descriptor_data);
  105. // Add a new timer queue to the reactor.
  106. template <typename Time_Traits>
  107. void add_timer_queue(timer_queue<Time_Traits>& queue);
  108. // Remove a timer queue from the reactor.
  109. template <typename Time_Traits>
  110. void remove_timer_queue(timer_queue<Time_Traits>& queue);
  111. // Schedule a new operation in the given timer queue to expire at the
  112. // specified absolute time.
  113. template <typename Time_Traits>
  114. void schedule_timer(timer_queue<Time_Traits>& queue,
  115. const typename Time_Traits::time_type& time,
  116. typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op);
  117. // Cancel the timer operations associated with the given token. Returns the
  118. // number of operations that have been posted or dispatched.
  119. template <typename Time_Traits>
  120. std::size_t cancel_timer(timer_queue<Time_Traits>& queue,
  121. typename timer_queue<Time_Traits>::per_timer_data& timer,
  122. std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)());
  123. // Move the timer operations associated with the given timer.
  124. template <typename Time_Traits>
  125. void move_timer(timer_queue<Time_Traits>& queue,
  126. typename timer_queue<Time_Traits>::per_timer_data& target,
  127. typename timer_queue<Time_Traits>::per_timer_data& source);
  128. // Run select once until interrupted or events are ready to be dispatched.
  129. BOOST_ASIO_DECL void run(long usec, op_queue<operation>& ops);
  130. // Interrupt the select loop.
  131. BOOST_ASIO_DECL void interrupt();
  132. private:
  133. #if defined(BOOST_ASIO_HAS_IOCP)
  134. // Run the select loop in the thread.
  135. BOOST_ASIO_DECL void run_thread();
  136. #endif // defined(BOOST_ASIO_HAS_IOCP)
  137. // Helper function to add a new timer queue.
  138. BOOST_ASIO_DECL void do_add_timer_queue(timer_queue_base& queue);
  139. // Helper function to remove a timer queue.
  140. BOOST_ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue);
  141. // Get the timeout value for the select call.
  142. BOOST_ASIO_DECL timeval* get_timeout(long usec, timeval& tv);
  143. // Cancel all operations associated with the given descriptor. This function
  144. // does not acquire the select_reactor's mutex.
  145. BOOST_ASIO_DECL void cancel_ops_unlocked(socket_type descriptor,
  146. const boost::system::error_code& ec);
  147. // The scheduler implementation used to post completions.
  148. # if defined(BOOST_ASIO_HAS_IOCP)
  149. typedef class win_iocp_io_context scheduler_type;
  150. # else // defined(BOOST_ASIO_HAS_IOCP)
  151. typedef class scheduler scheduler_type;
  152. # endif // defined(BOOST_ASIO_HAS_IOCP)
  153. scheduler_type& scheduler_;
  154. // Mutex to protect access to internal data.
  155. boost::asio::detail::mutex mutex_;
  156. // The interrupter is used to break a blocking select call.
  157. select_interrupter interrupter_;
  158. // The queues of read, write and except operations.
  159. reactor_op_queue<socket_type> op_queue_[max_ops];
  160. // The file descriptor sets to be passed to the select system call.
  161. fd_set_adapter fd_sets_[max_select_ops];
  162. // The timer queues.
  163. timer_queue_set timer_queues_;
  164. #if defined(BOOST_ASIO_HAS_IOCP)
  165. // Helper class to run the reactor loop in a thread.
  166. class thread_function;
  167. friend class thread_function;
  168. // Does the reactor loop thread need to stop.
  169. bool stop_thread_;
  170. // The thread that is running the reactor loop.
  171. boost::asio::detail::thread* thread_;
  172. #endif // defined(BOOST_ASIO_HAS_IOCP)
  173. // Whether the service has been shut down.
  174. bool shutdown_;
  175. };
  176. } // namespace detail
  177. } // namespace asio
  178. } // namespace boost
  179. #include <boost/asio/detail/pop_options.hpp>
  180. #include <boost/asio/detail/impl/select_reactor.hpp>
  181. #if defined(BOOST_ASIO_HEADER_ONLY)
  182. # include <boost/asio/detail/impl/select_reactor.ipp>
  183. #endif // defined(BOOST_ASIO_HEADER_ONLY)
  184. #endif // defined(BOOST_ASIO_HAS_IOCP)
  185. // || (!defined(BOOST_ASIO_HAS_DEV_POLL)
  186. // && !defined(BOOST_ASIO_HAS_EPOLL)
  187. // && !defined(BOOST_ASIO_HAS_KQUEUE)
  188. // && !defined(BOOST_ASIO_WINDOWS_RUNTIME))
  189. #endif // BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP