ceph/src/boost/boost/asio/posix/basic_descriptor.hpp

   1 //
   2 // posix/basic_descriptor.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_POSIX_BASIC_DESCRIPTOR_HPP
  12 #define BOOST_ASIO_POSIX_BASIC_DESCRIPTOR_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_POSIX_STREAM_DESCRIPTOR) \
  21   || defined(GENERATING_DOCUMENTATION)
  22
  23 #include <boost/asio/async_result.hpp>
  24 #include <boost/asio/detail/handler_type_requirements.hpp>
  25 #include <boost/asio/detail/io_object_impl.hpp>
  26 #include <boost/asio/detail/non_const_lvalue.hpp>
  27 #include <boost/asio/detail/reactive_descriptor_service.hpp>
  28 #include <boost/asio/detail/throw_error.hpp>
  29 #include <boost/asio/error.hpp>
  30 #include <boost/asio/execution_context.hpp>
  31 #include <boost/asio/executor.hpp>
  32 #include <boost/asio/posix/descriptor_base.hpp>
  33
  34 #if defined(BOOST_ASIO_HAS_MOVE)
  35 # include <utility>
  36 #endif // defined(BOOST_ASIO_HAS_MOVE)
  37
  38 #include <boost/asio/detail/push_options.hpp>
  39
  40 namespace boost {
  41 namespace asio {
  42 namespace posix {
  43
  44 /// Provides POSIX descriptor functionality.
  45 /**
  46  * The posix::basic_descriptor class template provides the ability to wrap a
  47  * POSIX descriptor.
  48  *
  49  * @par Thread Safety
  50  * @e Distinct @e objects: Safe.@n
  51  * @e Shared @e objects: Unsafe.
  52  */
  53 template <typename Executor = executor>
  54 class basic_descriptor
  55   : public descriptor_base
  56 {
  57 public:
  58   /// The type of the executor associated with the object.
  59   typedef Executor executor_type;
  60
  61   /// Rebinds the descriptor type to another executor.
  62   template <typename Executor1>
  63   struct rebind_executor
  64   {
  65     /// The descriptor type when rebound to the specified executor.
  66     typedef basic_descriptor<Executor1> other;
  67   };
  68
  69   /// The native representation of a descriptor.
  70 #if defined(GENERATING_DOCUMENTATION)
  71   typedef implementation_defined native_handle_type;
  72 #else
  73   typedef detail::reactive_descriptor_service::native_handle_type
  74     native_handle_type;
  75 #endif
  76
  77   /// A descriptor is always the lowest layer.
  78   typedef basic_descriptor lowest_layer_type;
  79
  80   /// Construct a descriptor without opening it.
  81   /**
  82    * This constructor creates a descriptor without opening it.
  83    *
  84    * @param ex The I/O executor that the descriptor will use, by default, to
  85    * dispatch handlers for any asynchronous operations performed on the
  86    * descriptor.
  87    */
  88   explicit basic_descriptor(const executor_type& ex)
  89     : impl_(ex)
  90   {
  91   }
  92
  93   /// Construct a descriptor without opening it.
  94   /**
  95    * This constructor creates a descriptor without opening it.
  96    *
  97    * @param context An execution context which provides the I/O executor that
  98    * the descriptor will use, by default, to dispatch handlers for any
  99    * asynchronous operations performed on the descriptor.
 100    */
 101   template <typename ExecutionContext>
 102   explicit basic_descriptor(ExecutionContext& context,
 103       typename enable_if<
 104         is_convertible<ExecutionContext&, execution_context&>::value
 105       >::type* = 0)
 106     : impl_(context)
 107   {
 108   }
 109
 110   /// Construct a descriptor on an existing native descriptor.
 111   /**
 112    * This constructor creates a descriptor object to hold an existing native
 113    * descriptor.
 114    *
 115    * @param ex The I/O executor that the descriptor will use, by default, to
 116    * dispatch handlers for any asynchronous operations performed on the
 117    * descriptor.
 118    *
 119    * @param native_descriptor A native descriptor.
 120    *
 121    * @throws boost::system::system_error Thrown on failure.
 122    */
 123   basic_descriptor(const executor_type& ex,
 124       const native_handle_type& native_descriptor)
 125     : impl_(ex)
 126   {
 127     boost::system::error_code ec;
 128     impl_.get_service().assign(impl_.get_implementation(),
 129         native_descriptor, ec);
 130     boost::asio::detail::throw_error(ec, "assign");
 131   }
 132
 133   /// Construct a descriptor on an existing native descriptor.
 134   /**
 135    * This constructor creates a descriptor object to hold an existing native
 136    * descriptor.
 137    *
 138    * @param context An execution context which provides the I/O executor that
 139    * the descriptor will use, by default, to dispatch handlers for any
 140    * asynchronous operations performed on the descriptor.
 141    *
 142    * @param native_descriptor A native descriptor.
 143    *
 144    * @throws boost::system::system_error Thrown on failure.
 145    */
 146   template <typename ExecutionContext>
 147   basic_descriptor(ExecutionContext& context,
 148       const native_handle_type& native_descriptor,
 149       typename enable_if<
 150         is_convertible<ExecutionContext&, execution_context&>::value
 151       >::type* = 0)
 152     : impl_(context)
 153   {
 154     boost::system::error_code ec;
 155     impl_.get_service().assign(impl_.get_implementation(),
 156         native_descriptor, ec);
 157     boost::asio::detail::throw_error(ec, "assign");
 158   }
 159
 160 #if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
 161   /// Move-construct a descriptor from another.
 162   /**
 163    * This constructor moves a descriptor from one object to another.
 164    *
 165    * @param other The other descriptor object from which the move will
 166    * occur.
 167    *
 168    * @note Following the move, the moved-from object is in the same state as if
 169    * constructed using the @c basic_descriptor(const executor_type&)
 170    * constructor.
 171    */
 172   basic_descriptor(basic_descriptor&& other)
 173     : impl_(std::move(other.impl_))
 174   {
 175   }
 176
 177   /// Move-assign a descriptor from another.
 178   /**
 179    * This assignment operator moves a descriptor from one object to another.
 180    *
 181    * @param other The other descriptor object from which the move will
 182    * occur.
 183    *
 184    * @note Following the move, the moved-from object is in the same state as if
 185    * constructed using the @c basic_descriptor(const executor_type&)
 186    * constructor.
 187    */
 188   basic_descriptor& operator=(basic_descriptor&& other)
 189   {
 190     impl_ = std::move(other.impl_);
 191     return *this;
 192   }
 193 #endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
 194
 195   /// Get the executor associated with the object.
 196   executor_type get_executor() BOOST_ASIO_NOEXCEPT
 197   {
 198     return impl_.get_executor();
 199   }
 200
 201   /// Get a reference to the lowest layer.
 202   /**
 203    * This function returns a reference to the lowest layer in a stack of
 204    * layers. Since a descriptor cannot contain any further layers, it
 205    * simply returns a reference to itself.
 206    *
 207    * @return A reference to the lowest layer in the stack of layers. Ownership
 208    * is not transferred to the caller.
 209    */
 210   lowest_layer_type& lowest_layer()
 211   {
 212     return *this;
 213   }
 214
 215   /// Get a const reference to the lowest layer.
 216   /**
 217    * This function returns a const reference to the lowest layer in a stack of
 218    * layers. Since a descriptor cannot contain any further layers, it
 219    * simply returns a reference to itself.
 220    *
 221    * @return A const reference to the lowest layer in the stack of layers.
 222    * Ownership is not transferred to the caller.
 223    */
 224   const lowest_layer_type& lowest_layer() const
 225   {
 226     return *this;
 227   }
 228
 229   /// Assign an existing native descriptor to the descriptor.
 230   /*
 231    * This function opens the descriptor to hold an existing native descriptor.
 232    *
 233    * @param native_descriptor A native descriptor.
 234    *
 235    * @throws boost::system::system_error Thrown on failure.
 236    */
 237   void assign(const native_handle_type& native_descriptor)
 238   {
 239     boost::system::error_code ec;
 240     impl_.get_service().assign(impl_.get_implementation(),
 241         native_descriptor, ec);
 242     boost::asio::detail::throw_error(ec, "assign");
 243   }
 244
 245   /// Assign an existing native descriptor to the descriptor.
 246   /*
 247    * This function opens the descriptor to hold an existing native descriptor.
 248    *
 249    * @param native_descriptor A native descriptor.
 250    *
 251    * @param ec Set to indicate what error occurred, if any.
 252    */
 253   BOOST_ASIO_SYNC_OP_VOID assign(const native_handle_type& native_descriptor,
 254       boost::system::error_code& ec)
 255   {
 256     impl_.get_service().assign(
 257         impl_.get_implementation(), native_descriptor, ec);
 258     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 259   }
 260
 261   /// Determine whether the descriptor is open.
 262   bool is_open() const
 263   {
 264     return impl_.get_service().is_open(impl_.get_implementation());
 265   }
 266
 267   /// Close the descriptor.
 268   /**
 269    * This function is used to close the descriptor. Any asynchronous read or
 270    * write operations will be cancelled immediately, and will complete with the
 271    * boost::asio::error::operation_aborted error.
 272    *
 273    * @throws boost::system::system_error Thrown on failure. Note that, even if
 274    * the function indicates an error, the underlying descriptor is closed.
 275    */
 276   void close()
 277   {
 278     boost::system::error_code ec;
 279     impl_.get_service().close(impl_.get_implementation(), ec);
 280     boost::asio::detail::throw_error(ec, "close");
 281   }
 282
 283   /// Close the descriptor.
 284   /**
 285    * This function is used to close the descriptor. Any asynchronous read or
 286    * write operations will be cancelled immediately, and will complete with the
 287    * boost::asio::error::operation_aborted error.
 288    *
 289    * @param ec Set to indicate what error occurred, if any. Note that, even if
 290    * the function indicates an error, the underlying descriptor is closed.
 291    */
 292   BOOST_ASIO_SYNC_OP_VOID close(boost::system::error_code& ec)
 293   {
 294     impl_.get_service().close(impl_.get_implementation(), ec);
 295     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 296   }
 297
 298   /// Get the native descriptor representation.
 299   /**
 300    * This function may be used to obtain the underlying representation of the
 301    * descriptor. This is intended to allow access to native descriptor
 302    * functionality that is not otherwise provided.
 303    */
 304   native_handle_type native_handle()
 305   {
 306     return impl_.get_service().native_handle(impl_.get_implementation());
 307   }
 308
 309   /// Release ownership of the native descriptor implementation.
 310   /**
 311    * This function may be used to obtain the underlying representation of the
 312    * descriptor. After calling this function, @c is_open() returns false. The
 313    * caller is responsible for closing the descriptor.
 314    *
 315    * All outstanding asynchronous read or write operations will finish
 316    * immediately, and the handlers for cancelled operations will be passed the
 317    * boost::asio::error::operation_aborted error.
 318    */
 319   native_handle_type release()
 320   {
 321     return impl_.get_service().release(impl_.get_implementation());
 322   }
 323
 324   /// Cancel all asynchronous operations associated with the descriptor.
 325   /**
 326    * This function causes all outstanding asynchronous read or write operations
 327    * to finish immediately, and the handlers for cancelled operations will be
 328    * passed the boost::asio::error::operation_aborted error.
 329    *
 330    * @throws boost::system::system_error Thrown on failure.
 331    */
 332   void cancel()
 333   {
 334     boost::system::error_code ec;
 335     impl_.get_service().cancel(impl_.get_implementation(), ec);
 336     boost::asio::detail::throw_error(ec, "cancel");
 337   }
 338
 339   /// Cancel all asynchronous operations associated with the descriptor.
 340   /**
 341    * This function causes all outstanding asynchronous read or write operations
 342    * to finish immediately, and the handlers for cancelled operations will be
 343    * passed the boost::asio::error::operation_aborted error.
 344    *
 345    * @param ec Set to indicate what error occurred, if any.
 346    */
 347   BOOST_ASIO_SYNC_OP_VOID cancel(boost::system::error_code& ec)
 348   {
 349     impl_.get_service().cancel(impl_.get_implementation(), ec);
 350     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 351   }
 352
 353   /// Perform an IO control command on the descriptor.
 354   /**
 355    * This function is used to execute an IO control command on the descriptor.
 356    *
 357    * @param command The IO control command to be performed on the descriptor.
 358    *
 359    * @throws boost::system::system_error Thrown on failure.
 360    *
 361    * @sa IoControlCommand @n
 362    * boost::asio::posix::descriptor_base::bytes_readable @n
 363    * boost::asio::posix::descriptor_base::non_blocking_io
 364    *
 365    * @par Example
 366    * Getting the number of bytes ready to read:
 367    * @code
 368    * boost::asio::posix::stream_descriptor descriptor(my_context);
 369    * ...
 370    * boost::asio::posix::stream_descriptor::bytes_readable command;
 371    * descriptor.io_control(command);
 372    * std::size_t bytes_readable = command.get();
 373    * @endcode
 374    */
 375   template <typename IoControlCommand>
 376   void io_control(IoControlCommand& command)
 377   {
 378     boost::system::error_code ec;
 379     impl_.get_service().io_control(impl_.get_implementation(), command, ec);
 380     boost::asio::detail::throw_error(ec, "io_control");
 381   }
 382
 383   /// Perform an IO control command on the descriptor.
 384   /**
 385    * This function is used to execute an IO control command on the descriptor.
 386    *
 387    * @param command The IO control command to be performed on the descriptor.
 388    *
 389    * @param ec Set to indicate what error occurred, if any.
 390    *
 391    * @sa IoControlCommand @n
 392    * boost::asio::posix::descriptor_base::bytes_readable @n
 393    * boost::asio::posix::descriptor_base::non_blocking_io
 394    *
 395    * @par Example
 396    * Getting the number of bytes ready to read:
 397    * @code
 398    * boost::asio::posix::stream_descriptor descriptor(my_context);
 399    * ...
 400    * boost::asio::posix::stream_descriptor::bytes_readable command;
 401    * boost::system::error_code ec;
 402    * descriptor.io_control(command, ec);
 403    * if (ec)
 404    * {
 405    *   // An error occurred.
 406    * }
 407    * std::size_t bytes_readable = command.get();
 408    * @endcode
 409    */
 410   template <typename IoControlCommand>
 411   BOOST_ASIO_SYNC_OP_VOID io_control(IoControlCommand& command,
 412       boost::system::error_code& ec)
 413   {
 414     impl_.get_service().io_control(impl_.get_implementation(), command, ec);
 415     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 416   }
 417
 418   /// Gets the non-blocking mode of the descriptor.
 419   /**
 420    * @returns @c true if the descriptor's synchronous operations will fail with
 421    * boost::asio::error::would_block if they are unable to perform the requested
 422    * operation immediately. If @c false, synchronous operations will block
 423    * until complete.
 424    *
 425    * @note The non-blocking mode has no effect on the behaviour of asynchronous
 426    * operations. Asynchronous operations will never fail with the error
 427    * boost::asio::error::would_block.
 428    */
 429   bool non_blocking() const
 430   {
 431     return impl_.get_service().non_blocking(impl_.get_implementation());
 432   }
 433
 434   /// Sets the non-blocking mode of the descriptor.
 435   /**
 436    * @param mode If @c true, the descriptor's synchronous operations will fail
 437    * with boost::asio::error::would_block if they are unable to perform the
 438    * requested operation immediately. If @c false, synchronous operations will
 439    * block until complete.
 440    *
 441    * @throws boost::system::system_error Thrown on failure.
 442    *
 443    * @note The non-blocking mode has no effect on the behaviour of asynchronous
 444    * operations. Asynchronous operations will never fail with the error
 445    * boost::asio::error::would_block.
 446    */
 447   void non_blocking(bool mode)
 448   {
 449     boost::system::error_code ec;
 450     impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
 451     boost::asio::detail::throw_error(ec, "non_blocking");
 452   }
 453
 454   /// Sets the non-blocking mode of the descriptor.
 455   /**
 456    * @param mode If @c true, the descriptor's synchronous operations will fail
 457    * with boost::asio::error::would_block if they are unable to perform the
 458    * requested operation immediately. If @c false, synchronous operations will
 459    * block until complete.
 460    *
 461    * @param ec Set to indicate what error occurred, if any.
 462    *
 463    * @note The non-blocking mode has no effect on the behaviour of asynchronous
 464    * operations. Asynchronous operations will never fail with the error
 465    * boost::asio::error::would_block.
 466    */
 467   BOOST_ASIO_SYNC_OP_VOID non_blocking(
 468       bool mode, boost::system::error_code& ec)
 469   {
 470     impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
 471     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 472   }
 473
 474   /// Gets the non-blocking mode of the native descriptor implementation.
 475   /**
 476    * This function is used to retrieve the non-blocking mode of the underlying
 477    * native descriptor. This mode has no effect on the behaviour of the
 478    * descriptor object's synchronous operations.
 479    *
 480    * @returns @c true if the underlying descriptor is in non-blocking mode and
 481    * direct system calls may fail with boost::asio::error::would_block (or the
 482    * equivalent system error).
 483    *
 484    * @note The current non-blocking mode is cached by the descriptor object.
 485    * Consequently, the return value may be incorrect if the non-blocking mode
 486    * was set directly on the native descriptor.
 487    */
 488   bool native_non_blocking() const
 489   {
 490     return impl_.get_service().native_non_blocking(
 491         impl_.get_implementation());
 492   }
 493
 494   /// Sets the non-blocking mode of the native descriptor implementation.
 495   /**
 496    * This function is used to modify the non-blocking mode of the underlying
 497    * native descriptor. It has no effect on the behaviour of the descriptor
 498    * object's synchronous operations.
 499    *
 500    * @param mode If @c true, the underlying descriptor is put into non-blocking
 501    * mode and direct system calls may fail with boost::asio::error::would_block
 502    * (or the equivalent system error).
 503    *
 504    * @throws boost::system::system_error Thrown on failure. If the @c mode is
 505    * @c false, but the current value of @c non_blocking() is @c true, this
 506    * function fails with boost::asio::error::invalid_argument, as the
 507    * combination does not make sense.
 508    */
 509   void native_non_blocking(bool mode)
 510   {
 511     boost::system::error_code ec;
 512     impl_.get_service().native_non_blocking(
 513         impl_.get_implementation(), mode, ec);
 514     boost::asio::detail::throw_error(ec, "native_non_blocking");
 515   }
 516
 517   /// Sets the non-blocking mode of the native descriptor implementation.
 518   /**
 519    * This function is used to modify the non-blocking mode of the underlying
 520    * native descriptor. It has no effect on the behaviour of the descriptor
 521    * object's synchronous operations.
 522    *
 523    * @param mode If @c true, the underlying descriptor is put into non-blocking
 524    * mode and direct system calls may fail with boost::asio::error::would_block
 525    * (or the equivalent system error).
 526    *
 527    * @param ec Set to indicate what error occurred, if any. If the @c mode is
 528    * @c false, but the current value of @c non_blocking() is @c true, this
 529    * function fails with boost::asio::error::invalid_argument, as the
 530    * combination does not make sense.
 531    */
 532   BOOST_ASIO_SYNC_OP_VOID native_non_blocking(
 533       bool mode, boost::system::error_code& ec)
 534   {
 535     impl_.get_service().native_non_blocking(
 536         impl_.get_implementation(), mode, ec);
 537     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 538   }
 539
 540   /// Wait for the descriptor to become ready to read, ready to write, or to
 541   /// have pending error conditions.
 542   /**
 543    * This function is used to perform a blocking wait for a descriptor to enter
 544    * a ready to read, write or error condition state.
 545    *
 546    * @param w Specifies the desired descriptor state.
 547    *
 548    * @par Example
 549    * Waiting for a descriptor to become readable.
 550    * @code
 551    * boost::asio::posix::stream_descriptor descriptor(my_context);
 552    * ...
 553    * descriptor.wait(boost::asio::posix::stream_descriptor::wait_read);
 554    * @endcode
 555    */
 556   void wait(wait_type w)
 557   {
 558     boost::system::error_code ec;
 559     impl_.get_service().wait(impl_.get_implementation(), w, ec);
 560     boost::asio::detail::throw_error(ec, "wait");
 561   }
 562
 563   /// Wait for the descriptor to become ready to read, ready to write, or to
 564   /// have pending error conditions.
 565   /**
 566    * This function is used to perform a blocking wait for a descriptor to enter
 567    * a ready to read, write or error condition state.
 568    *
 569    * @param w Specifies the desired descriptor state.
 570    *
 571    * @param ec Set to indicate what error occurred, if any.
 572    *
 573    * @par Example
 574    * Waiting for a descriptor to become readable.
 575    * @code
 576    * boost::asio::posix::stream_descriptor descriptor(my_context);
 577    * ...
 578    * boost::system::error_code ec;
 579    * descriptor.wait(boost::asio::posix::stream_descriptor::wait_read, ec);
 580    * @endcode
 581    */
 582   BOOST_ASIO_SYNC_OP_VOID wait(wait_type w, boost::system::error_code& ec)
 583   {
 584     impl_.get_service().wait(impl_.get_implementation(), w, ec);
 585     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 586   }
 587
 588   /// Asynchronously wait for the descriptor to become ready to read, ready to
 589   /// write, or to have pending error conditions.
 590   /**
 591    * This function is used to perform an asynchronous wait for a descriptor to
 592    * enter a ready to read, write or error condition state.
 593    *
 594    * @param w Specifies the desired descriptor state.
 595    *
 596    * @param handler The handler to be called when the wait operation completes.
 597    * Copies will be made of the handler as required. The function signature of
 598    * the handler must be:
 599    * @code void handler(
 600    *   const boost::system::error_code& error // Result of operation
 601    * ); @endcode
 602    * Regardless of whether the asynchronous operation completes immediately or
 603    * not, the handler will not be invoked from within this function. On
 604    * immediate completion, invocation of the handler will be performed in a
 605    * manner equivalent to using boost::asio::post().
 606    *
 607    * @par Example
 608    * @code
 609    * void wait_handler(const boost::system::error_code& error)
 610    * {
 611    *   if (!error)
 612    *   {
 613    *     // Wait succeeded.
 614    *   }
 615    * }
 616    *
 617    * ...
 618    *
 619    * boost::asio::posix::stream_descriptor descriptor(my_context);
 620    * ...
 621    * descriptor.async_wait(
 622    *     boost::asio::posix::stream_descriptor::wait_read,
 623    *     wait_handler);
 624    * @endcode
 625    */
 626   template <
 627       BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code))
 628         WaitHandler BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
 629   BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(WaitHandler,
 630       void (boost::system::error_code))
 631   async_wait(wait_type w,
 632       BOOST_ASIO_MOVE_ARG(WaitHandler) handler
 633         BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
 634   {
 635     return async_initiate<WaitHandler, void (boost::system::error_code)>(
 636         initiate_async_wait(this), handler, w);
 637   }
 638
 639 protected:
 640   /// Protected destructor to prevent deletion through this type.
 641   /**
 642    * This function destroys the descriptor, cancelling any outstanding
 643    * asynchronous wait operations associated with the descriptor as if by
 644    * calling @c cancel.
 645    */
 646   ~basic_descriptor()
 647   {
 648   }
 649
 650   detail::io_object_impl<detail::reactive_descriptor_service, Executor> impl_;
 651
 652 private:
 653   // Disallow copying and assignment.
 654   basic_descriptor(const basic_descriptor&) BOOST_ASIO_DELETED;
 655   basic_descriptor& operator=(const basic_descriptor&) BOOST_ASIO_DELETED;
 656
 657   class initiate_async_wait
 658   {
 659   public:
 660     typedef Executor executor_type;
 661
 662     explicit initiate_async_wait(basic_descriptor* self)
 663       : self_(self)
 664     {
 665     }
 666
 667     executor_type get_executor() const BOOST_ASIO_NOEXCEPT
 668     {
 669       return self_->get_executor();
 670     }
 671
 672     template <typename WaitHandler>
 673     void operator()(BOOST_ASIO_MOVE_ARG(WaitHandler) handler, wait_type w) const
 674     {
 675       // If you get an error on the following line it means that your handler
 676       // does not meet the documented type requirements for a WaitHandler.
 677       BOOST_ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
 678
 679       detail::non_const_lvalue<WaitHandler> handler2(handler);
 680       self_->impl_.get_service().async_wait(
 681           self_->impl_.get_implementation(), w, handler2.value,
 682           self_->impl_.get_implementation_executor());
 683     }
 684
 685   private:
 686     basic_descriptor* self_;
 687   };
 688 };
 689
 690 } // namespace posix
 691 } // namespace asio
 692 } // namespace boost
 693
 694 #include <boost/asio/detail/pop_options.hpp>
 695
 696 #endif // defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
 697        //   || defined(GENERATING_DOCUMENTATION)
 698
 699 #endif // BOOST_ASIO_POSIX_BASIC_DESCRIPTOR_HPP