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

   1 //
   2 // detail/select_reactor.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2017 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/select_interrupter.hpp>
  34 #include <boost/asio/detail/socket_types.hpp>
  35 #include <boost/asio/detail/timer_queue_base.hpp>
  36 #include <boost/asio/detail/timer_queue_set.hpp>
  37 #include <boost/asio/detail/wait_op.hpp>
  38 #include <boost/asio/execution_context.hpp>
  39
  40 #if defined(BOOST_ASIO_HAS_IOCP)
  41 # include <boost/asio/detail/thread.hpp>
  42 #endif // defined(BOOST_ASIO_HAS_IOCP)
  43
  44 #include <boost/asio/detail/push_options.hpp>
  45
  46 namespace boost {
  47 namespace asio {
  48 namespace detail {
  49
  50 class select_reactor
  51   : public execution_context_service_base<select_reactor>
  52 {
  53 public:
  54 #if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  55   enum op_types { read_op = 0, write_op = 1, except_op = 2,
  56     max_select_ops = 3, connect_op = 3, max_ops = 4 };
  57 #else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  58   enum op_types { read_op = 0, write_op = 1, except_op = 2,
  59     max_select_ops = 3, connect_op = 1, max_ops = 3 };
  60 #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
  61
  62   // Per-descriptor data.
  63   struct per_descriptor_data
  64   {
  65   };
  66
  67   // Constructor.
  68   BOOST_ASIO_DECL select_reactor(boost::asio::execution_context& ctx);
  69
  70   // Destructor.
  71   BOOST_ASIO_DECL ~select_reactor();
  72
  73   // Destroy all user-defined handler objects owned by the service.
  74   BOOST_ASIO_DECL void shutdown();
  75
  76   // Recreate internal descriptors following a fork.
  77   BOOST_ASIO_DECL void notify_fork(
  78       boost::asio::execution_context::fork_event fork_ev);
  79
  80   // Initialise the task, but only if the reactor is not in its own thread.
  81   BOOST_ASIO_DECL void init_task();
  82
  83   // Register a socket with the reactor. Returns 0 on success, system error
  84   // code on failure.
  85   BOOST_ASIO_DECL int register_descriptor(socket_type, per_descriptor_data&);
  86
  87   // Register a descriptor with an associated single operation. Returns 0 on
  88   // success, system error code on failure.
  89   BOOST_ASIO_DECL int register_internal_descriptor(
  90       int op_type, socket_type descriptor,
  91       per_descriptor_data& descriptor_data, reactor_op* op);
  92
  93   // Post a reactor operation for immediate completion.
  94   void post_immediate_completion(reactor_op* op, bool is_continuation)
  95   {
  96     scheduler_.post_immediate_completion(op, is_continuation);
  97   }
  98
  99   // Start a new operation. The reactor operation will be performed when the
 100   // given descriptor is flagged as ready, or an error has occurred.
 101   BOOST_ASIO_DECL void start_op(int op_type, socket_type descriptor,
 102       per_descriptor_data&, reactor_op* op, bool is_continuation, bool);
 103
 104   // Cancel all operations associated with the given descriptor. The
 105   // handlers associated with the descriptor will be invoked with the
 106   // operation_aborted error.
 107   BOOST_ASIO_DECL void cancel_ops(socket_type descriptor, per_descriptor_data&);
 108
 109   // Cancel any operations that are running against the descriptor and remove
 110   // its registration from the reactor. The reactor resources associated with
 111   // the descriptor must be released by calling cleanup_descriptor_data.
 112   BOOST_ASIO_DECL void deregister_descriptor(socket_type descriptor,
 113       per_descriptor_data&, bool closing);
 114
 115   // Remove the descriptor's registration from the reactor. The reactor
 116   // resources associated with the descriptor must be released by calling
 117   // cleanup_descriptor_data.
 118   BOOST_ASIO_DECL void deregister_internal_descriptor(
 119       socket_type descriptor, per_descriptor_data&);
 120
 121   // Perform any post-deregistration cleanup tasks associated with the
 122   // descriptor data.
 123   BOOST_ASIO_DECL void cleanup_descriptor_data(per_descriptor_data&);
 124
 125   // Move descriptor registration from one descriptor_data object to another.
 126   BOOST_ASIO_DECL void move_descriptor(socket_type descriptor,
 127       per_descriptor_data& target_descriptor_data,
 128       per_descriptor_data& source_descriptor_data);
 129
 130   // Add a new timer queue to the reactor.
 131   template <typename Time_Traits>
 132   void add_timer_queue(timer_queue<Time_Traits>& queue);
 133
 134   // Remove a timer queue from the reactor.
 135   template <typename Time_Traits>
 136   void remove_timer_queue(timer_queue<Time_Traits>& queue);
 137
 138   // Schedule a new operation in the given timer queue to expire at the
 139   // specified absolute time.
 140   template <typename Time_Traits>
 141   void schedule_timer(timer_queue<Time_Traits>& queue,
 142       const typename Time_Traits::time_type& time,
 143       typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op);
 144
 145   // Cancel the timer operations associated with the given token. Returns the
 146   // number of operations that have been posted or dispatched.
 147   template <typename Time_Traits>
 148   std::size_t cancel_timer(timer_queue<Time_Traits>& queue,
 149       typename timer_queue<Time_Traits>::per_timer_data& timer,
 150       std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)());
 151
 152   // Move the timer operations associated with the given timer.
 153   template <typename Time_Traits>
 154   void move_timer(timer_queue<Time_Traits>& queue,
 155       typename timer_queue<Time_Traits>::per_timer_data& target,
 156       typename timer_queue<Time_Traits>::per_timer_data& source);
 157
 158   // Run select once until interrupted or events are ready to be dispatched.
 159   BOOST_ASIO_DECL void run(long usec, op_queue<operation>& ops);
 160
 161   // Interrupt the select loop.
 162   BOOST_ASIO_DECL void interrupt();
 163
 164 private:
 165 #if defined(BOOST_ASIO_HAS_IOCP)
 166   // Run the select loop in the thread.
 167   BOOST_ASIO_DECL void run_thread();
 168 #endif // defined(BOOST_ASIO_HAS_IOCP)
 169
 170   // Helper function to add a new timer queue.
 171   BOOST_ASIO_DECL void do_add_timer_queue(timer_queue_base& queue);
 172
 173   // Helper function to remove a timer queue.
 174   BOOST_ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue);
 175
 176   // Get the timeout value for the select call.
 177   BOOST_ASIO_DECL timeval* get_timeout(long usec, timeval& tv);
 178
 179   // Cancel all operations associated with the given descriptor. This function
 180   // does not acquire the select_reactor's mutex.
 181   BOOST_ASIO_DECL void cancel_ops_unlocked(socket_type descriptor,
 182       const boost::system::error_code& ec);
 183
 184   // The scheduler implementation used to post completions.
 185 # if defined(BOOST_ASIO_HAS_IOCP)
 186   typedef class win_iocp_io_context scheduler_type;
 187 # else // defined(BOOST_ASIO_HAS_IOCP)
 188   typedef class scheduler scheduler_type;
 189 # endif // defined(BOOST_ASIO_HAS_IOCP)
 190   scheduler_type& scheduler_;
 191
 192   // Mutex to protect access to internal data.
 193   boost::asio::detail::mutex mutex_;
 194
 195   // The interrupter is used to break a blocking select call.
 196   select_interrupter interrupter_;
 197
 198   // The queues of read, write and except operations.
 199   reactor_op_queue<socket_type> op_queue_[max_ops];
 200
 201   // The file descriptor sets to be passed to the select system call.
 202   fd_set_adapter fd_sets_[max_select_ops];
 203
 204   // The timer queues.
 205   timer_queue_set timer_queues_;
 206
 207 #if defined(BOOST_ASIO_HAS_IOCP)
 208   // Helper class to run the reactor loop in a thread.
 209   class thread_function;
 210   friend class thread_function;
 211
 212   // Does the reactor loop thread need to stop.
 213   bool stop_thread_;
 214
 215   // The thread that is running the reactor loop.
 216   boost::asio::detail::thread* thread_;
 217 #endif // defined(BOOST_ASIO_HAS_IOCP)
 218
 219   // Whether the service has been shut down.
 220   bool shutdown_;
 221 };
 222
 223 } // namespace detail
 224 } // namespace asio
 225 } // namespace boost
 226
 227 #include <boost/asio/detail/pop_options.hpp>
 228
 229 #include <boost/asio/detail/impl/select_reactor.hpp>
 230 #if defined(BOOST_ASIO_HEADER_ONLY)
 231 # include <boost/asio/detail/impl/select_reactor.ipp>
 232 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 233
 234 #endif // defined(BOOST_ASIO_HAS_IOCP)
 235        //   || (!defined(BOOST_ASIO_HAS_DEV_POLL)
 236        //       && !defined(BOOST_ASIO_HAS_EPOLL)
 237        //       && !defined(BOOST_ASIO_HAS_KQUEUE)
 238        //       && !defined(BOOST_ASIO_WINDOWS_RUNTIME))
 239
 240 #endif // BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP