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

   1 //
   2 // detail/win_iocp_socket_service_base.hpp
   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
  11 #ifndef BOOST_ASIO_DETAIL_WIN_IOCP_SOCKET_SERVICE_BASE_HPP
  12 #define BOOST_ASIO_DETAIL_WIN_IOCP_SOCKET_SERVICE_BASE_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
  22 #include <boost/asio/error.hpp>
  23 #include <boost/asio/execution_context.hpp>
  24 #include <boost/asio/socket_base.hpp>
  25 #include <boost/asio/detail/bind_handler.hpp>
  26 #include <boost/asio/detail/buffer_sequence_adapter.hpp>
  27 #include <boost/asio/detail/fenced_block.hpp>
  28 #include <boost/asio/detail/handler_alloc_helpers.hpp>
  29 #include <boost/asio/detail/handler_invoke_helpers.hpp>
  30 #include <boost/asio/detail/memory.hpp>
  31 #include <boost/asio/detail/mutex.hpp>
  32 #include <boost/asio/detail/operation.hpp>
  33 #include <boost/asio/detail/reactor_op.hpp>
  34 #include <boost/asio/detail/select_reactor.hpp>
  35 #include <boost/asio/detail/socket_holder.hpp>
  36 #include <boost/asio/detail/socket_ops.hpp>
  37 #include <boost/asio/detail/socket_types.hpp>
  38 #include <boost/asio/detail/win_iocp_io_context.hpp>
  39 #include <boost/asio/detail/win_iocp_null_buffers_op.hpp>
  40 #include <boost/asio/detail/win_iocp_socket_connect_op.hpp>
  41 #include <boost/asio/detail/win_iocp_socket_send_op.hpp>
  42 #include <boost/asio/detail/win_iocp_socket_recv_op.hpp>
  43 #include <boost/asio/detail/win_iocp_socket_recvmsg_op.hpp>
  44 #include <boost/asio/detail/win_iocp_wait_op.hpp>
  45
  46 #include <boost/asio/detail/push_options.hpp>
  47
  48 namespace boost {
  49 namespace asio {
  50 namespace detail {
  51
  52 class win_iocp_socket_service_base
  53 {
  54 public:
  55   // The implementation type of the socket.
  56   struct base_implementation_type
  57   {
  58     // The native socket representation.
  59     socket_type socket_;
  60
  61     // The current state of the socket.
  62     socket_ops::state_type state_;
  63
  64     // We use a shared pointer as a cancellation token here to work around the
  65     // broken Windows support for cancellation. MSDN says that when you call
  66     // closesocket any outstanding WSARecv or WSASend operations will complete
  67     // with the error ERROR_OPERATION_ABORTED. In practice they complete with
  68     // ERROR_NETNAME_DELETED, which means you can't tell the difference between
  69     // a local cancellation and the socket being hard-closed by the peer.
  70     socket_ops::shared_cancel_token_type cancel_token_;
  71
  72     // Per-descriptor data used by the reactor.
  73     select_reactor::per_descriptor_data reactor_data_;
  74
  75 #if defined(BOOST_ASIO_ENABLE_CANCELIO)
  76     // The ID of the thread from which it is safe to cancel asynchronous
  77     // operations. 0 means no asynchronous operations have been started yet.
  78     // ~0 means asynchronous operations have been started from more than one
  79     // thread, and cancellation is not supported for the socket.
  80     DWORD safe_cancellation_thread_id_;
  81 #endif // defined(BOOST_ASIO_ENABLE_CANCELIO)
  82
  83     // Pointers to adjacent socket implementations in linked list.
  84     base_implementation_type* next_;
  85     base_implementation_type* prev_;
  86   };
  87
  88   // Constructor.
  89   BOOST_ASIO_DECL win_iocp_socket_service_base(execution_context& context);
  90
  91   // Destroy all user-defined handler objects owned by the service.
  92   BOOST_ASIO_DECL void base_shutdown();
  93
  94   // Construct a new socket implementation.
  95   BOOST_ASIO_DECL void construct(base_implementation_type& impl);
  96
  97   // Move-construct a new socket implementation.
  98   BOOST_ASIO_DECL void base_move_construct(base_implementation_type& impl,
  99       base_implementation_type& other_impl) BOOST_ASIO_NOEXCEPT;
 100
 101   // Move-assign from another socket implementation.
 102   BOOST_ASIO_DECL void base_move_assign(base_implementation_type& impl,
 103       win_iocp_socket_service_base& other_service,
 104       base_implementation_type& other_impl);
 105
 106   // Destroy a socket implementation.
 107   BOOST_ASIO_DECL void destroy(base_implementation_type& impl);
 108
 109   // Determine whether the socket is open.
 110   bool is_open(const base_implementation_type& impl) const
 111   {
 112     return impl.socket_ != invalid_socket;
 113   }
 114
 115   // Destroy a socket implementation.
 116   BOOST_ASIO_DECL boost::system::error_code close(
 117       base_implementation_type& impl, boost::system::error_code& ec);
 118
 119   // Release ownership of the socket.
 120   BOOST_ASIO_DECL socket_type release(
 121       base_implementation_type& impl, boost::system::error_code& ec);
 122
 123   // Cancel all operations associated with the socket.
 124   BOOST_ASIO_DECL boost::system::error_code cancel(
 125       base_implementation_type& impl, boost::system::error_code& ec);
 126
 127   // Determine whether the socket is at the out-of-band data mark.
 128   bool at_mark(const base_implementation_type& impl,
 129       boost::system::error_code& ec) const
 130   {
 131     return socket_ops::sockatmark(impl.socket_, ec);
 132   }
 133
 134   // Determine the number of bytes available for reading.
 135   std::size_t available(const base_implementation_type& impl,
 136       boost::system::error_code& ec) const
 137   {
 138     return socket_ops::available(impl.socket_, ec);
 139   }
 140
 141   // Place the socket into the state where it will listen for new connections.
 142   boost::system::error_code listen(base_implementation_type& impl,
 143       int backlog, boost::system::error_code& ec)
 144   {
 145     socket_ops::listen(impl.socket_, backlog, ec);
 146     return ec;
 147   }
 148
 149   // Perform an IO control command on the socket.
 150   template <typename IO_Control_Command>
 151   boost::system::error_code io_control(base_implementation_type& impl,
 152       IO_Control_Command& command, boost::system::error_code& ec)
 153   {
 154     socket_ops::ioctl(impl.socket_, impl.state_, command.name(),
 155         static_cast<ioctl_arg_type*>(command.data()), ec);
 156     return ec;
 157   }
 158
 159   // Gets the non-blocking mode of the socket.
 160   bool non_blocking(const base_implementation_type& impl) const
 161   {
 162     return (impl.state_ & socket_ops::user_set_non_blocking) != 0;
 163   }
 164
 165   // Sets the non-blocking mode of the socket.
 166   boost::system::error_code non_blocking(base_implementation_type& impl,
 167       bool mode, boost::system::error_code& ec)
 168   {
 169     socket_ops::set_user_non_blocking(impl.socket_, impl.state_, mode, ec);
 170     return ec;
 171   }
 172
 173   // Gets the non-blocking mode of the native socket implementation.
 174   bool native_non_blocking(const base_implementation_type& impl) const
 175   {
 176     return (impl.state_ & socket_ops::internal_non_blocking) != 0;
 177   }
 178
 179   // Sets the non-blocking mode of the native socket implementation.
 180   boost::system::error_code native_non_blocking(base_implementation_type& impl,
 181       bool mode, boost::system::error_code& ec)
 182   {
 183     socket_ops::set_internal_non_blocking(impl.socket_, impl.state_, mode, ec);
 184     return ec;
 185   }
 186
 187   // Wait for the socket to become ready to read, ready to write, or to have
 188   // pending error conditions.
 189   boost::system::error_code wait(base_implementation_type& impl,
 190       socket_base::wait_type w, boost::system::error_code& ec)
 191   {
 192     switch (w)
 193     {
 194     case socket_base::wait_read:
 195       socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
 196       break;
 197     case socket_base::wait_write:
 198       socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
 199       break;
 200     case socket_base::wait_error:
 201       socket_ops::poll_error(impl.socket_, impl.state_, -1, ec);
 202       break;
 203     default:
 204       ec = boost::asio::error::invalid_argument;
 205       break;
 206     }
 207
 208     return ec;
 209   }
 210
 211   // Asynchronously wait for the socket to become ready to read, ready to
 212   // write, or to have pending error conditions.
 213   template <typename Handler, typename IoExecutor>
 214   void async_wait(base_implementation_type& impl,
 215       socket_base::wait_type w, Handler& handler, const IoExecutor& io_ex)
 216   {
 217     bool is_continuation =
 218       boost_asio_handler_cont_helpers::is_continuation(handler);
 219
 220     // Allocate and construct an operation to wrap the handler.
 221     typedef win_iocp_wait_op<Handler, IoExecutor> op;
 222     typename op::ptr p = { boost::asio::detail::addressof(handler),
 223       op::ptr::allocate(handler), 0 };
 224     p.p = new (p.v) op(impl.cancel_token_, handler, io_ex);
 225
 226     BOOST_ASIO_HANDLER_CREATION((context_, *p.p, "socket",
 227           &impl, impl.socket_, "async_wait"));
 228
 229     switch (w)
 230     {
 231       case socket_base::wait_read:
 232         start_null_buffers_receive_op(impl, 0, p.p);
 233         break;
 234       case socket_base::wait_write:
 235         start_reactor_op(impl, select_reactor::write_op, p.p);
 236         break;
 237       case socket_base::wait_error:
 238         start_reactor_op(impl, select_reactor::except_op, p.p);
 239         break;
 240       default:
 241         p.p->ec_ = boost::asio::error::invalid_argument;
 242         iocp_service_.post_immediate_completion(p.p, is_continuation);
 243         break;
 244     }
 245
 246     p.v = p.p = 0;
 247   }
 248
 249   // Send the given data to the peer. Returns the number of bytes sent.
 250   template <typename ConstBufferSequence>
 251   size_t send(base_implementation_type& impl,
 252       const ConstBufferSequence& buffers,
 253       socket_base::message_flags flags, boost::system::error_code& ec)
 254   {
 255     buffer_sequence_adapter<boost::asio::const_buffer,
 256         ConstBufferSequence> bufs(buffers);
 257
 258     return socket_ops::sync_send(impl.socket_, impl.state_,
 259         bufs.buffers(), bufs.count(), flags, bufs.all_empty(), ec);
 260   }
 261
 262   // Wait until data can be sent without blocking.
 263   size_t send(base_implementation_type& impl, const null_buffers&,
 264       socket_base::message_flags, boost::system::error_code& ec)
 265   {
 266     // Wait for socket to become ready.
 267     socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
 268
 269     return 0;
 270   }
 271
 272   // Start an asynchronous send. The data being sent must be valid for the
 273   // lifetime of the asynchronous operation.
 274   template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
 275   void async_send(base_implementation_type& impl,
 276       const ConstBufferSequence& buffers, socket_base::message_flags flags,
 277       Handler& handler, const IoExecutor& io_ex)
 278   {
 279     // Allocate and construct an operation to wrap the handler.
 280     typedef win_iocp_socket_send_op<
 281         ConstBufferSequence, Handler, IoExecutor> op;
 282     typename op::ptr p = { boost::asio::detail::addressof(handler),
 283       op::ptr::allocate(handler), 0 };
 284     p.p = new (p.v) op(impl.cancel_token_, buffers, handler, io_ex);
 285
 286     BOOST_ASIO_HANDLER_CREATION((context_, *p.p, "socket",
 287           &impl, impl.socket_, "async_send"));
 288
 289     buffer_sequence_adapter<boost::asio::const_buffer,
 290         ConstBufferSequence> bufs(buffers);
 291
 292     start_send_op(impl, bufs.buffers(), bufs.count(), flags,
 293         (impl.state_ & socket_ops::stream_oriented) != 0 && bufs.all_empty(),
 294         p.p);
 295     p.v = p.p = 0;
 296   }
 297
 298   // Start an asynchronous wait until data can be sent without blocking.
 299   template <typename Handler, typename IoExecutor>
 300   void async_send(base_implementation_type& impl, const null_buffers&,
 301       socket_base::message_flags, Handler& handler, const IoExecutor& io_ex)
 302   {
 303     // Allocate and construct an operation to wrap the handler.
 304     typedef win_iocp_null_buffers_op<Handler, IoExecutor> op;
 305     typename op::ptr p = { boost::asio::detail::addressof(handler),
 306       op::ptr::allocate(handler), 0 };
 307     p.p = new (p.v) op(impl.cancel_token_, handler, io_ex);
 308
 309     BOOST_ASIO_HANDLER_CREATION((context_, *p.p, "socket",
 310           &impl, impl.socket_, "async_send(null_buffers)"));
 311
 312     start_reactor_op(impl, select_reactor::write_op, p.p);
 313     p.v = p.p = 0;
 314   }
 315
 316   // Receive some data from the peer. Returns the number of bytes received.
 317   template <typename MutableBufferSequence>
 318   size_t receive(base_implementation_type& impl,
 319       const MutableBufferSequence& buffers,
 320       socket_base::message_flags flags, boost::system::error_code& ec)
 321   {
 322     buffer_sequence_adapter<boost::asio::mutable_buffer,
 323         MutableBufferSequence> bufs(buffers);
 324
 325     return socket_ops::sync_recv(impl.socket_, impl.state_,
 326         bufs.buffers(), bufs.count(), flags, bufs.all_empty(), ec);
 327   }
 328
 329   // Wait until data can be received without blocking.
 330   size_t receive(base_implementation_type& impl, const null_buffers&,
 331       socket_base::message_flags, boost::system::error_code& ec)
 332   {
 333     // Wait for socket to become ready.
 334     socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
 335
 336     return 0;
 337   }
 338
 339   // Start an asynchronous receive. The buffer for the data being received
 340   // must be valid for the lifetime of the asynchronous operation.
 341   template <typename MutableBufferSequence,
 342       typename Handler, typename IoExecutor>
 343   void async_receive(base_implementation_type& impl,
 344       const MutableBufferSequence& buffers, socket_base::message_flags flags,
 345       Handler& handler, const IoExecutor& io_ex)
 346   {
 347     // Allocate and construct an operation to wrap the handler.
 348     typedef win_iocp_socket_recv_op<
 349         MutableBufferSequence, Handler, IoExecutor> op;
 350     typename op::ptr p = { boost::asio::detail::addressof(handler),
 351       op::ptr::allocate(handler), 0 };
 352     p.p = new (p.v) op(impl.state_, impl.cancel_token_,
 353         buffers, handler, io_ex);
 354
 355     BOOST_ASIO_HANDLER_CREATION((context_, *p.p, "socket",
 356           &impl, impl.socket_, "async_receive"));
 357
 358     buffer_sequence_adapter<boost::asio::mutable_buffer,
 359         MutableBufferSequence> bufs(buffers);
 360
 361     start_receive_op(impl, bufs.buffers(), bufs.count(), flags,
 362         (impl.state_ & socket_ops::stream_oriented) != 0 && bufs.all_empty(),
 363         p.p);
 364     p.v = p.p = 0;
 365   }
 366
 367   // Wait until data can be received without blocking.
 368   template <typename Handler, typename IoExecutor>
 369   void async_receive(base_implementation_type& impl,
 370       const null_buffers&, socket_base::message_flags flags,
 371       Handler& handler, const IoExecutor& io_ex)
 372   {
 373     // Allocate and construct an operation to wrap the handler.
 374     typedef win_iocp_null_buffers_op<Handler, IoExecutor> op;
 375     typename op::ptr p = { boost::asio::detail::addressof(handler),
 376       op::ptr::allocate(handler), 0 };
 377     p.p = new (p.v) op(impl.cancel_token_, handler, io_ex);
 378
 379     BOOST_ASIO_HANDLER_CREATION((context_, *p.p, "socket",
 380           &impl, impl.socket_, "async_receive(null_buffers)"));
 381
 382     start_null_buffers_receive_op(impl, flags, p.p);
 383     p.v = p.p = 0;
 384   }
 385
 386   // Receive some data with associated flags. Returns the number of bytes
 387   // received.
 388   template <typename MutableBufferSequence>
 389   size_t receive_with_flags(base_implementation_type& impl,
 390       const MutableBufferSequence& buffers,
 391       socket_base::message_flags in_flags,
 392       socket_base::message_flags& out_flags, boost::system::error_code& ec)
 393   {
 394     buffer_sequence_adapter<boost::asio::mutable_buffer,
 395         MutableBufferSequence> bufs(buffers);
 396
 397     return socket_ops::sync_recvmsg(impl.socket_, impl.state_,
 398         bufs.buffers(), bufs.count(), in_flags, out_flags, ec);
 399   }
 400
 401   // Wait until data can be received without blocking.
 402   size_t receive_with_flags(base_implementation_type& impl,
 403       const null_buffers&, socket_base::message_flags,
 404       socket_base::message_flags& out_flags, boost::system::error_code& ec)
 405   {
 406     // Wait for socket to become ready.
 407     socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
 408
 409     // Clear out_flags, since we cannot give it any other sensible value when
 410     // performing a null_buffers operation.
 411     out_flags = 0;
 412
 413     return 0;
 414   }
 415
 416   // Start an asynchronous receive. The buffer for the data being received
 417   // must be valid for the lifetime of the asynchronous operation.
 418   template <typename MutableBufferSequence,
 419       typename Handler, typename IoExecutor>
 420   void async_receive_with_flags(base_implementation_type& impl,
 421       const MutableBufferSequence& buffers, socket_base::message_flags in_flags,
 422       socket_base::message_flags& out_flags, Handler& handler,
 423       const IoExecutor& io_ex)
 424   {
 425     // Allocate and construct an operation to wrap the handler.
 426     typedef win_iocp_socket_recvmsg_op<
 427         MutableBufferSequence, Handler, IoExecutor> op;
 428     typename op::ptr p = { boost::asio::detail::addressof(handler),
 429       op::ptr::allocate(handler), 0 };
 430     p.p = new (p.v) op(impl.cancel_token_,
 431         buffers, out_flags, handler, io_ex);
 432
 433     BOOST_ASIO_HANDLER_CREATION((context_, *p.p, "socket",
 434           &impl, impl.socket_, "async_receive_with_flags"));
 435
 436     buffer_sequence_adapter<boost::asio::mutable_buffer,
 437         MutableBufferSequence> bufs(buffers);
 438
 439     start_receive_op(impl, bufs.buffers(), bufs.count(), in_flags, false, p.p);
 440     p.v = p.p = 0;
 441   }
 442
 443   // Wait until data can be received without blocking.
 444   template <typename Handler, typename IoExecutor>
 445   void async_receive_with_flags(base_implementation_type& impl,
 446       const null_buffers&, socket_base::message_flags in_flags,
 447       socket_base::message_flags& out_flags, Handler& handler,
 448       const IoExecutor& io_ex)
 449   {
 450     // Allocate and construct an operation to wrap the handler.
 451     typedef win_iocp_null_buffers_op<Handler, IoExecutor> op;
 452     typename op::ptr p = { boost::asio::detail::addressof(handler),
 453       op::ptr::allocate(handler), 0 };
 454     p.p = new (p.v) op(impl.cancel_token_, handler, io_ex);
 455
 456     BOOST_ASIO_HANDLER_CREATION((context_, *p.p, "socket",
 457           &impl, impl.socket_, "async_receive_with_flags(null_buffers)"));
 458
 459     // Reset out_flags since it can be given no sensible value at this time.
 460     out_flags = 0;
 461
 462     start_null_buffers_receive_op(impl, in_flags, p.p);
 463     p.v = p.p = 0;
 464   }
 465
 466   // Helper function to restart an asynchronous accept operation.
 467   BOOST_ASIO_DECL void restart_accept_op(socket_type s,
 468       socket_holder& new_socket, int family, int type, int protocol,
 469       void* output_buffer, DWORD address_length, operation* op);
 470
 471 protected:
 472   // Open a new socket implementation.
 473   BOOST_ASIO_DECL boost::system::error_code do_open(
 474       base_implementation_type& impl, int family, int type,
 475       int protocol, boost::system::error_code& ec);
 476
 477   // Assign a native socket to a socket implementation.
 478   BOOST_ASIO_DECL boost::system::error_code do_assign(
 479       base_implementation_type& impl, int type,
 480       socket_type native_socket, boost::system::error_code& ec);
 481
 482   // Helper function to start an asynchronous send operation.
 483   BOOST_ASIO_DECL void start_send_op(base_implementation_type& impl,
 484       WSABUF* buffers, std::size_t buffer_count,
 485       socket_base::message_flags flags, bool noop, operation* op);
 486
 487   // Helper function to start an asynchronous send_to operation.
 488   BOOST_ASIO_DECL void start_send_to_op(base_implementation_type& impl,
 489       WSABUF* buffers, std::size_t buffer_count,
 490       const socket_addr_type* addr, int addrlen,
 491       socket_base::message_flags flags, operation* op);
 492
 493   // Helper function to start an asynchronous receive operation.
 494   BOOST_ASIO_DECL void start_receive_op(base_implementation_type& impl,
 495       WSABUF* buffers, std::size_t buffer_count,
 496       socket_base::message_flags flags, bool noop, operation* op);
 497
 498   // Helper function to start an asynchronous null_buffers receive operation.
 499   BOOST_ASIO_DECL void start_null_buffers_receive_op(
 500       base_implementation_type& impl,
 501       socket_base::message_flags flags, reactor_op* op);
 502
 503   // Helper function to start an asynchronous receive_from operation.
 504   BOOST_ASIO_DECL void start_receive_from_op(base_implementation_type& impl,
 505       WSABUF* buffers, std::size_t buffer_count, socket_addr_type* addr,
 506       socket_base::message_flags flags, int* addrlen, operation* op);
 507
 508   // Helper function to start an asynchronous accept operation.
 509   BOOST_ASIO_DECL void start_accept_op(base_implementation_type& impl,
 510       bool peer_is_open, socket_holder& new_socket, int family, int type,
 511       int protocol, void* output_buffer, DWORD address_length, operation* op);
 512
 513   // Start an asynchronous read or write operation using the reactor.
 514   BOOST_ASIO_DECL void start_reactor_op(base_implementation_type& impl,
 515       int op_type, reactor_op* op);
 516
 517   // Start the asynchronous connect operation using the reactor.
 518   BOOST_ASIO_DECL void start_connect_op(base_implementation_type& impl,
 519       int family, int type, const socket_addr_type* remote_addr,
 520       std::size_t remote_addrlen, win_iocp_socket_connect_op_base* op);
 521
 522   // Helper function to close a socket when the associated object is being
 523   // destroyed.
 524   BOOST_ASIO_DECL void close_for_destruction(base_implementation_type& impl);
 525
 526   // Update the ID of the thread from which cancellation is safe.
 527   BOOST_ASIO_DECL void update_cancellation_thread_id(
 528       base_implementation_type& impl);
 529
 530   // Helper function to get the reactor. If no reactor has been created yet, a
 531   // new one is obtained from the execution context and a pointer to it is
 532   // cached in this service.
 533   BOOST_ASIO_DECL select_reactor& get_reactor();
 534
 535   // The type of a ConnectEx function pointer, as old SDKs may not provide it.
 536   typedef BOOL (PASCAL *connect_ex_fn)(SOCKET,
 537       const socket_addr_type*, int, void*, DWORD, DWORD*, OVERLAPPED*);
 538
 539   // Helper function to get the ConnectEx pointer. If no ConnectEx pointer has
 540   // been obtained yet, one is obtained using WSAIoctl and the pointer is
 541   // cached. Returns a null pointer if ConnectEx is not available.
 542   BOOST_ASIO_DECL connect_ex_fn get_connect_ex(
 543       base_implementation_type& impl, int type);
 544
 545   // The type of a NtSetInformationFile function pointer.
 546   typedef LONG (NTAPI *nt_set_info_fn)(HANDLE, ULONG_PTR*, void*, ULONG, ULONG);
 547
 548   // Helper function to get the NtSetInformationFile function pointer. If no
 549   // NtSetInformationFile pointer has been obtained yet, one is obtained using
 550   // GetProcAddress and the pointer is cached. Returns a null pointer if
 551   // NtSetInformationFile is not available.
 552   BOOST_ASIO_DECL nt_set_info_fn get_nt_set_info();
 553
 554   // Helper function to emulate InterlockedCompareExchangePointer functionality
 555   // for:
 556   // - very old Platform SDKs; and
 557   // - platform SDKs where MSVC's /Wp64 option causes spurious warnings.
 558   BOOST_ASIO_DECL void* interlocked_compare_exchange_pointer(
 559       void** dest, void* exch, void* cmp);
 560
 561   // Helper function to emulate InterlockedExchangePointer functionality for:
 562   // - very old Platform SDKs; and
 563   // - platform SDKs where MSVC's /Wp64 option causes spurious warnings.
 564   BOOST_ASIO_DECL void* interlocked_exchange_pointer(void** dest, void* val);
 565
 566   // The execution context used to obtain the reactor, if required.
 567   execution_context& context_;
 568
 569   // The IOCP service used for running asynchronous operations and dispatching
 570   // handlers.
 571   win_iocp_io_context& iocp_service_;
 572
 573   // The reactor used for performing connect operations. This object is created
 574   // only if needed.
 575   select_reactor* reactor_;
 576
 577   // Pointer to ConnectEx implementation.
 578   void* connect_ex_;
 579
 580   // Pointer to NtSetInformationFile implementation.
 581   void* nt_set_info_;
 582
 583   // Mutex to protect access to the linked list of implementations.
 584   boost::asio::detail::mutex mutex_;
 585
 586   // The head of a linked list of all implementations.
 587   base_implementation_type* impl_list_;
 588 };
 589
 590 } // namespace detail
 591 } // namespace asio
 592 } // namespace boost
 593
 594 #include <boost/asio/detail/pop_options.hpp>
 595
 596 #if defined(BOOST_ASIO_HEADER_ONLY)
 597 # include <boost/asio/detail/impl/win_iocp_socket_service_base.ipp>
 598 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 599
 600 #endif // defined(BOOST_ASIO_HAS_IOCP)
 601
 602 #endif // BOOST_ASIO_DETAIL_WIN_IOCP_SOCKET_SERVICE_BASE_HPP