ceph/src/boost/boost/asio/detail/select_reactor.hpp

   1 //
   2 // detail/select_reactor.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2022 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
  11 #ifndef BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP
  12 #define BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19
  20 #if defined(BOOST_ASIO_HAS_IOCP) \
  21   || (!defined(BOOST_ASIO_HAS_DEV_POLL) \
  22       && !defined(BOOST_ASIO_HAS_EPOLL) \
  23       && !defined(BOOST_ASIO_HAS_KQUEUE) \
  24       && !defined(BOOST_ASIO_WINDOWS_RUNTIME))
  25
  26 #include <cstddef>
  27 #include <boost/asio/detail/fd_set_adapter.hpp>
  28 #include <boost/asio/detail/limits.hpp>
  29 #include <boost/asio/detail/mutex.hpp>
  30 #include <boost/asio/detail/op_queue.hpp>
  31 #include <boost/asio/detail/reactor_op.hpp>
  32 #include <boost/asio/detail/reactor_op_queue.hpp>
  33 #include <boost/asio/detail/scheduler_task.hpp>
  34 #include <boost/asio/detail/select_interrupter.hpp>
  35 #include <boost/asio/detail/socket_types.hpp>
  36 #include <boost/asio/detail/timer_queue_base.hpp>
  37 #include <boost/asio/detail/timer_queue_set.hpp>
  38 #include <boost/asio/detail/wait_op.hpp>
  39 #include <boost/asio/execution_context.hpp>
  40
  41 #if defined(BOOST_ASIO_HAS_IOCP)
  42 # include <boost/asio/detail/thread.hpp>
  43 #endif // defined(BOOST_ASIO_HAS_IOCP)
  44
  45 #include <boost/asio/detail/push_options.hpp>
  46
  47 namespace boost {
  48 namespace asio {
  49 namespace detail {
  50
  51 class select_reactor
  52   : public execution_context_service_base<select_reactor>
  53 #if !defined(BOOST_ASIO_HAS_IOCP)
  54     , public scheduler_task
  55 #endif // !defined(BOOST_ASIO_HAS_IOCP)
  56 {
  57 public:
  58 #if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  59   enum op_types { read_op = 0, write_op = 1, except_op = 2,
  60     max_select_ops = 3, connect_op = 3, max_ops = 4 };
  61 #else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  62   enum op_types { read_op = 0, write_op = 1, except_op = 2,
  63     max_select_ops = 3, connect_op = 1, max_ops = 3 };
  64 #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  65
  66   // Per-descriptor data.
  67   struct per_descriptor_data
  68   {
  69   };
  70
  71   // Constructor.
  72   BOOST_ASIO_DECL select_reactor(boost::asio::execution_context& ctx);
  73
  74   // Destructor.
  75   BOOST_ASIO_DECL ~select_reactor();
  76
  77   // Destroy all user-defined handler objects owned by the service.
  78   BOOST_ASIO_DECL void shutdown();
  79
  80   // Recreate internal descriptors following a fork.
  81   BOOST_ASIO_DECL void notify_fork(
  82       boost::asio::execution_context::fork_event fork_ev);
  83
  84   // Initialise the task, but only if the reactor is not in its own thread.
  85   BOOST_ASIO_DECL void init_task();
  86
  87   // Register a socket with the reactor. Returns 0 on success, system error
  88   // code on failure.
  89   BOOST_ASIO_DECL int register_descriptor(socket_type, per_descriptor_data&);
  90
  91   // Register a descriptor with an associated single operation. Returns 0 on
  92   // success, system error code on failure.
  93   BOOST_ASIO_DECL int register_internal_descriptor(
  94       int op_type, socket_type descriptor,
  95       per_descriptor_data& descriptor_data, reactor_op* op);
  96
  97   // Post a reactor operation for immediate completion.
  98   void post_immediate_completion(reactor_op* op, bool is_continuation);
  99
 100   // Start a new operation. The reactor operation will be performed when the
 101   // given descriptor is flagged as ready, or an error has occurred.
 102   BOOST_ASIO_DECL void start_op(int op_type, socket_type descriptor,
 103       per_descriptor_data&, reactor_op* op, bool is_continuation, bool);
 104
 105   // Cancel all operations associated with the given descriptor. The
 106   // handlers associated with the descriptor will be invoked with the
 107   // operation_aborted error.
 108   BOOST_ASIO_DECL void cancel_ops(socket_type descriptor, per_descriptor_data&);
 109
 110   // Cancel all operations associated with the given descriptor and key. The
 111   // handlers associated with the descriptor will be invoked with the
 112   // operation_aborted error.
 113   BOOST_ASIO_DECL void cancel_ops_by_key(socket_type descriptor,
 114       per_descriptor_data& descriptor_data,
 115       int op_type, void* cancellation_key);
 116
 117   // Cancel any operations that are running against the descriptor and remove
 118   // its registration from the reactor. The reactor resources associated with
 119   // the descriptor must be released by calling cleanup_descriptor_data.
 120   BOOST_ASIO_DECL void deregister_descriptor(socket_type descriptor,
 121       per_descriptor_data&, bool closing);
 122
 123   // Remove the descriptor's registration from the reactor. The reactor
 124   // resources associated with the descriptor must be released by calling
 125   // cleanup_descriptor_data.
 126   BOOST_ASIO_DECL void deregister_internal_descriptor(
 127       socket_type descriptor, per_descriptor_data&);
 128
 129   // Perform any post-deregistration cleanup tasks associated with the
 130   // descriptor data.
 131   BOOST_ASIO_DECL void cleanup_descriptor_data(per_descriptor_data&);
 132
 133   // Move descriptor registration from one descriptor_data object to another.
 134   BOOST_ASIO_DECL void move_descriptor(socket_type descriptor,
 135       per_descriptor_data& target_descriptor_data,
 136       per_descriptor_data& source_descriptor_data);
 137
 138   // Add a new timer queue to the reactor.
 139   template <typename Time_Traits>
 140   void add_timer_queue(timer_queue<Time_Traits>& queue);
 141
 142   // Remove a timer queue from the reactor.
 143   template <typename Time_Traits>
 144   void remove_timer_queue(timer_queue<Time_Traits>& queue);
 145
 146   // Schedule a new operation in the given timer queue to expire at the
 147   // specified absolute time.
 148   template <typename Time_Traits>
 149   void schedule_timer(timer_queue<Time_Traits>& queue,
 150       const typename Time_Traits::time_type& time,
 151       typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op);
 152
 153   // Cancel the timer operations associated with the given token. Returns the
 154   // number of operations that have been posted or dispatched.
 155   template <typename Time_Traits>
 156   std::size_t cancel_timer(timer_queue<Time_Traits>& queue,
 157       typename timer_queue<Time_Traits>::per_timer_data& timer,
 158       std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)());
 159
 160   // Cancel the timer operations associated with the given key.
 161   template <typename Time_Traits>
 162   void cancel_timer_by_key(timer_queue<Time_Traits>& queue,
 163       typename timer_queue<Time_Traits>::per_timer_data* timer,
 164       void* cancellation_key);
 165
 166   // Move the timer operations associated with the given timer.
 167   template <typename Time_Traits>
 168   void move_timer(timer_queue<Time_Traits>& queue,
 169       typename timer_queue<Time_Traits>::per_timer_data& target,
 170       typename timer_queue<Time_Traits>::per_timer_data& source);
 171
 172   // Run select once until interrupted or events are ready to be dispatched.
 173   BOOST_ASIO_DECL void run(long usec, op_queue<operation>& ops);
 174
 175   // Interrupt the select loop.
 176   BOOST_ASIO_DECL void interrupt();
 177
 178 private:
 179 #if defined(BOOST_ASIO_HAS_IOCP)
 180   // Run the select loop in the thread.
 181   BOOST_ASIO_DECL void run_thread();
 182 #endif // defined(BOOST_ASIO_HAS_IOCP)
 183
 184   // Helper function to add a new timer queue.
 185   BOOST_ASIO_DECL void do_add_timer_queue(timer_queue_base& queue);
 186
 187   // Helper function to remove a timer queue.
 188   BOOST_ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue);
 189
 190   // Get the timeout value for the select call.
 191   BOOST_ASIO_DECL timeval* get_timeout(long usec, timeval& tv);
 192
 193   // Cancel all operations associated with the given descriptor. This function
 194   // does not acquire the select_reactor's mutex.
 195   BOOST_ASIO_DECL void cancel_ops_unlocked(socket_type descriptor,
 196       const boost::system::error_code& ec);
 197
 198   // The scheduler implementation used to post completions.
 199 # if defined(BOOST_ASIO_HAS_IOCP)
 200   typedef class win_iocp_io_context scheduler_type;
 201 # else // defined(BOOST_ASIO_HAS_IOCP)
 202   typedef class scheduler scheduler_type;
 203 # endif // defined(BOOST_ASIO_HAS_IOCP)
 204   scheduler_type& scheduler_;
 205
 206   // Mutex to protect access to internal data.
 207   boost::asio::detail::mutex mutex_;
 208
 209   // The interrupter is used to break a blocking select call.
 210   select_interrupter interrupter_;
 211
 212   // The queues of read, write and except operations.
 213   reactor_op_queue<socket_type> op_queue_[max_ops];
 214
 215   // The file descriptor sets to be passed to the select system call.
 216   fd_set_adapter fd_sets_[max_select_ops];
 217
 218   // The timer queues.
 219   timer_queue_set timer_queues_;
 220
 221 #if defined(BOOST_ASIO_HAS_IOCP)
 222   // Helper class to run the reactor loop in a thread.
 223   class thread_function;
 224   friend class thread_function;
 225
 226   // Does the reactor loop thread need to stop.
 227   bool stop_thread_;
 228
 229   // The thread that is running the reactor loop.
 230   boost::asio::detail::thread* thread_;
 231 #endif // defined(BOOST_ASIO_HAS_IOCP)
 232
 233   // Whether the service has been shut down.
 234   bool shutdown_;
 235 };
 236
 237 } // namespace detail
 238 } // namespace asio
 239 } // namespace boost
 240
 241 #include <boost/asio/detail/pop_options.hpp>
 242
 243 #include <boost/asio/detail/impl/select_reactor.hpp>
 244 #if defined(BOOST_ASIO_HEADER_ONLY)
 245 # include <boost/asio/detail/impl/select_reactor.ipp>
 246 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 247
 248 #endif // defined(BOOST_ASIO_HAS_IOCP)
 249        //   || (!defined(BOOST_ASIO_HAS_DEV_POLL)
 250        //       && !defined(BOOST_ASIO_HAS_EPOLL)
 251        //       && !defined(BOOST_ASIO_HAS_KQUEUE)
 252        //       && !defined(BOOST_ASIO_WINDOWS_RUNTIME))
 253
 254 #endif // BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP