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- //
- // posix/basic_descriptor.hpp
- // ~~~~~~~~~~~~~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
- //
- // Distributed under the Boost Software License, Version 1.0. (See accompanying
- // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- //
-
- #ifndef ASIO_POSIX_BASIC_DESCRIPTOR_HPP
- #define ASIO_POSIX_BASIC_DESCRIPTOR_HPP
-
- #if defined(_MSC_VER) && (_MSC_VER >= 1200)
- # pragma once
- #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
-
- #include "asio/detail/config.hpp"
-
- #if defined(ASIO_HAS_POSIX_STREAM_DESCRIPTOR) \
- || defined(GENERATING_DOCUMENTATION)
-
- #include "asio/basic_io_object.hpp"
- #include "asio/detail/throw_error.hpp"
- #include "asio/error.hpp"
- #include "asio/posix/descriptor_base.hpp"
-
- #include "asio/detail/push_options.hpp"
-
- namespace asio {
- namespace posix {
-
- /// Provides POSIX descriptor functionality.
- /**
- * The posix::basic_descriptor class template provides the ability to wrap a
- * POSIX descriptor.
- *
- * @par Thread Safety
- * @e Distinct @e objects: Safe.@n
- * @e Shared @e objects: Unsafe.
- */
- template <typename DescriptorService>
- class basic_descriptor
- : public basic_io_object<DescriptorService>,
- public descriptor_base
- {
- public:
- /// The native representation of a descriptor.
- typedef typename DescriptorService::native_handle_type native_handle_type;
-
- /// A basic_descriptor is always the lowest layer.
- typedef basic_descriptor<DescriptorService> lowest_layer_type;
-
- /// Construct a basic_descriptor without opening it.
- /**
- * This constructor creates a descriptor without opening it.
- *
- * @param io_context The io_context object that the descriptor will use to
- * dispatch handlers for any asynchronous operations performed on the
- * descriptor.
- */
- explicit basic_descriptor(asio::io_context& io_context)
- : basic_io_object<DescriptorService>(io_context)
- {
- }
-
- /// Construct a basic_descriptor on an existing native descriptor.
- /**
- * This constructor creates a descriptor object to hold an existing native
- * descriptor.
- *
- * @param io_context The io_context object that the descriptor will use to
- * dispatch handlers for any asynchronous operations performed on the
- * descriptor.
- *
- * @param native_descriptor A native descriptor.
- *
- * @throws asio::system_error Thrown on failure.
- */
- basic_descriptor(asio::io_context& io_context,
- const native_handle_type& native_descriptor)
- : basic_io_object<DescriptorService>(io_context)
- {
- asio::error_code ec;
- this->get_service().assign(this->get_implementation(),
- native_descriptor, ec);
- asio::detail::throw_error(ec, "assign");
- }
-
- #if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
- /// Move-construct a basic_descriptor from another.
- /**
- * This constructor moves a descriptor from one object to another.
- *
- * @param other The other basic_descriptor object from which the move will
- * occur.
- *
- * @note Following the move, the moved-from object is in the same state as if
- * constructed using the @c basic_descriptor(io_context&) constructor.
- */
- basic_descriptor(basic_descriptor&& other)
- : basic_io_object<DescriptorService>(
- ASIO_MOVE_CAST(basic_descriptor)(other))
- {
- }
-
- /// Move-assign a basic_descriptor from another.
- /**
- * This assignment operator moves a descriptor from one object to another.
- *
- * @param other The other basic_descriptor object from which the move will
- * occur.
- *
- * @note Following the move, the moved-from object is in the same state as if
- * constructed using the @c basic_descriptor(io_context&) constructor.
- */
- basic_descriptor& operator=(basic_descriptor&& other)
- {
- basic_io_object<DescriptorService>::operator=(
- ASIO_MOVE_CAST(basic_descriptor)(other));
- return *this;
- }
- #endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
-
- /// Get a reference to the lowest layer.
- /**
- * This function returns a reference to the lowest layer in a stack of
- * layers. Since a basic_descriptor cannot contain any further layers, it
- * simply returns a reference to itself.
- *
- * @return A reference to the lowest layer in the stack of layers. Ownership
- * is not transferred to the caller.
- */
- lowest_layer_type& lowest_layer()
- {
- return *this;
- }
-
- /// Get a const reference to the lowest layer.
- /**
- * This function returns a const reference to the lowest layer in a stack of
- * layers. Since a basic_descriptor cannot contain any further layers, it
- * simply returns a reference to itself.
- *
- * @return A const reference to the lowest layer in the stack of layers.
- * Ownership is not transferred to the caller.
- */
- const lowest_layer_type& lowest_layer() const
- {
- return *this;
- }
-
- /// Assign an existing native descriptor to the descriptor.
- /*
- * This function opens the descriptor to hold an existing native descriptor.
- *
- * @param native_descriptor A native descriptor.
- *
- * @throws asio::system_error Thrown on failure.
- */
- void assign(const native_handle_type& native_descriptor)
- {
- asio::error_code ec;
- this->get_service().assign(this->get_implementation(),
- native_descriptor, ec);
- asio::detail::throw_error(ec, "assign");
- }
-
- /// Assign an existing native descriptor to the descriptor.
- /*
- * This function opens the descriptor to hold an existing native descriptor.
- *
- * @param native_descriptor A native descriptor.
- *
- * @param ec Set to indicate what error occurred, if any.
- */
- asio::error_code assign(const native_handle_type& native_descriptor,
- asio::error_code& ec)
- {
- return this->get_service().assign(
- this->get_implementation(), native_descriptor, ec);
- }
-
- /// Determine whether the descriptor is open.
- bool is_open() const
- {
- return this->get_service().is_open(this->get_implementation());
- }
-
- /// Close the descriptor.
- /**
- * This function is used to close the descriptor. Any asynchronous read or
- * write operations will be cancelled immediately, and will complete with the
- * asio::error::operation_aborted error.
- *
- * @throws asio::system_error Thrown on failure. Note that, even if
- * the function indicates an error, the underlying descriptor is closed.
- */
- void close()
- {
- asio::error_code ec;
- this->get_service().close(this->get_implementation(), ec);
- asio::detail::throw_error(ec, "close");
- }
-
- /// Close the descriptor.
- /**
- * This function is used to close the descriptor. Any asynchronous read or
- * write operations will be cancelled immediately, and will complete with the
- * asio::error::operation_aborted error.
- *
- * @param ec Set to indicate what error occurred, if any. Note that, even if
- * the function indicates an error, the underlying descriptor is closed.
- */
- asio::error_code close(asio::error_code& ec)
- {
- return this->get_service().close(this->get_implementation(), ec);
- }
-
- /// Get the native descriptor representation.
- /**
- * This function may be used to obtain the underlying representation of the
- * descriptor. This is intended to allow access to native descriptor
- * functionality that is not otherwise provided.
- */
- native_handle_type native_handle()
- {
- return this->get_service().native_handle(this->get_implementation());
- }
-
- /// Release ownership of the native descriptor implementation.
- /**
- * This function may be used to obtain the underlying representation of the
- * descriptor. After calling this function, @c is_open() returns false. The
- * caller is responsible for closing the descriptor.
- *
- * All outstanding asynchronous read or write operations will finish
- * immediately, and the handlers for cancelled operations will be passed the
- * asio::error::operation_aborted error.
- */
- native_handle_type release()
- {
- return this->get_service().release(this->get_implementation());
- }
-
- /// Cancel all asynchronous operations associated with the descriptor.
- /**
- * This function causes all outstanding asynchronous read or write operations
- * to finish immediately, and the handlers for cancelled operations will be
- * passed the asio::error::operation_aborted error.
- *
- * @throws asio::system_error Thrown on failure.
- */
- void cancel()
- {
- asio::error_code ec;
- this->get_service().cancel(this->get_implementation(), ec);
- asio::detail::throw_error(ec, "cancel");
- }
-
- /// Cancel all asynchronous operations associated with the descriptor.
- /**
- * This function causes all outstanding asynchronous read or write operations
- * to finish immediately, and the handlers for cancelled operations will be
- * passed the asio::error::operation_aborted error.
- *
- * @param ec Set to indicate what error occurred, if any.
- */
- asio::error_code cancel(asio::error_code& ec)
- {
- return this->get_service().cancel(this->get_implementation(), ec);
- }
-
- /// Perform an IO control command on the descriptor.
- /**
- * This function is used to execute an IO control command on the descriptor.
- *
- * @param command The IO control command to be performed on the descriptor.
- *
- * @throws asio::system_error Thrown on failure.
- *
- * @sa IoControlCommand @n
- * asio::posix::descriptor_base::bytes_readable @n
- * asio::posix::descriptor_base::non_blocking_io
- *
- * @par Example
- * Getting the number of bytes ready to read:
- * @code
- * asio::posix::stream_descriptor descriptor(io_context);
- * ...
- * asio::posix::stream_descriptor::bytes_readable command;
- * descriptor.io_control(command);
- * std::size_t bytes_readable = command.get();
- * @endcode
- */
- template <typename IoControlCommand>
- void io_control(IoControlCommand& command)
- {
- asio::error_code ec;
- this->get_service().io_control(this->get_implementation(), command, ec);
- asio::detail::throw_error(ec, "io_control");
- }
-
- /// Perform an IO control command on the descriptor.
- /**
- * This function is used to execute an IO control command on the descriptor.
- *
- * @param command The IO control command to be performed on the descriptor.
- *
- * @param ec Set to indicate what error occurred, if any.
- *
- * @sa IoControlCommand @n
- * asio::posix::descriptor_base::bytes_readable @n
- * asio::posix::descriptor_base::non_blocking_io
- *
- * @par Example
- * Getting the number of bytes ready to read:
- * @code
- * asio::posix::stream_descriptor descriptor(io_context);
- * ...
- * asio::posix::stream_descriptor::bytes_readable command;
- * asio::error_code ec;
- * descriptor.io_control(command, ec);
- * if (ec)
- * {
- * // An error occurred.
- * }
- * std::size_t bytes_readable = command.get();
- * @endcode
- */
- template <typename IoControlCommand>
- asio::error_code io_control(IoControlCommand& command,
- asio::error_code& ec)
- {
- return this->get_service().io_control(
- this->get_implementation(), command, ec);
- }
-
- /// Gets the non-blocking mode of the descriptor.
- /**
- * @returns @c true if the descriptor's synchronous operations will fail with
- * asio::error::would_block if they are unable to perform the requested
- * operation immediately. If @c false, synchronous operations will block
- * until complete.
- *
- * @note The non-blocking mode has no effect on the behaviour of asynchronous
- * operations. Asynchronous operations will never fail with the error
- * asio::error::would_block.
- */
- bool non_blocking() const
- {
- return this->get_service().non_blocking(this->get_implementation());
- }
-
- /// Sets the non-blocking mode of the descriptor.
- /**
- * @param mode If @c true, the descriptor's synchronous operations will fail
- * with asio::error::would_block if they are unable to perform the
- * requested operation immediately. If @c false, synchronous operations will
- * block until complete.
- *
- * @throws asio::system_error Thrown on failure.
- *
- * @note The non-blocking mode has no effect on the behaviour of asynchronous
- * operations. Asynchronous operations will never fail with the error
- * asio::error::would_block.
- */
- void non_blocking(bool mode)
- {
- asio::error_code ec;
- this->get_service().non_blocking(this->get_implementation(), mode, ec);
- asio::detail::throw_error(ec, "non_blocking");
- }
-
- /// Sets the non-blocking mode of the descriptor.
- /**
- * @param mode If @c true, the descriptor's synchronous operations will fail
- * with asio::error::would_block if they are unable to perform the
- * requested operation immediately. If @c false, synchronous operations will
- * block until complete.
- *
- * @param ec Set to indicate what error occurred, if any.
- *
- * @note The non-blocking mode has no effect on the behaviour of asynchronous
- * operations. Asynchronous operations will never fail with the error
- * asio::error::would_block.
- */
- asio::error_code non_blocking(
- bool mode, asio::error_code& ec)
- {
- return this->get_service().non_blocking(
- this->get_implementation(), mode, ec);
- }
-
- /// Gets the non-blocking mode of the native descriptor implementation.
- /**
- * This function is used to retrieve the non-blocking mode of the underlying
- * native descriptor. This mode has no effect on the behaviour of the
- * descriptor object's synchronous operations.
- *
- * @returns @c true if the underlying descriptor is in non-blocking mode and
- * direct system calls may fail with asio::error::would_block (or the
- * equivalent system error).
- *
- * @note The current non-blocking mode is cached by the descriptor object.
- * Consequently, the return value may be incorrect if the non-blocking mode
- * was set directly on the native descriptor.
- */
- bool native_non_blocking() const
- {
- return this->get_service().native_non_blocking(
- this->get_implementation());
- }
-
- /// Sets the non-blocking mode of the native descriptor implementation.
- /**
- * This function is used to modify the non-blocking mode of the underlying
- * native descriptor. It has no effect on the behaviour of the descriptor
- * object's synchronous operations.
- *
- * @param mode If @c true, the underlying descriptor is put into non-blocking
- * mode and direct system calls may fail with asio::error::would_block
- * (or the equivalent system error).
- *
- * @throws asio::system_error Thrown on failure. If the @c mode is
- * @c false, but the current value of @c non_blocking() is @c true, this
- * function fails with asio::error::invalid_argument, as the
- * combination does not make sense.
- */
- void native_non_blocking(bool mode)
- {
- asio::error_code ec;
- this->get_service().native_non_blocking(
- this->get_implementation(), mode, ec);
- asio::detail::throw_error(ec, "native_non_blocking");
- }
-
- /// Sets the non-blocking mode of the native descriptor implementation.
- /**
- * This function is used to modify the non-blocking mode of the underlying
- * native descriptor. It has no effect on the behaviour of the descriptor
- * object's synchronous operations.
- *
- * @param mode If @c true, the underlying descriptor is put into non-blocking
- * mode and direct system calls may fail with asio::error::would_block
- * (or the equivalent system error).
- *
- * @param ec Set to indicate what error occurred, if any. If the @c mode is
- * @c false, but the current value of @c non_blocking() is @c true, this
- * function fails with asio::error::invalid_argument, as the
- * combination does not make sense.
- */
- asio::error_code native_non_blocking(
- bool mode, asio::error_code& ec)
- {
- return this->get_service().native_non_blocking(
- this->get_implementation(), mode, ec);
- }
-
- /// Wait for the descriptor to become ready to read, ready to write, or to
- /// have pending error conditions.
- /**
- * This function is used to perform a blocking wait for a descriptor to enter
- * a ready to read, write or error condition state.
- *
- * @param w Specifies the desired descriptor state.
- *
- * @par Example
- * Waiting for a descriptor to become readable.
- * @code
- * asio::posix::stream_descriptor descriptor(io_context);
- * ...
- * descriptor.wait(asio::posix::stream_descriptor::wait_read);
- * @endcode
- */
- void wait(wait_type w)
- {
- asio::error_code ec;
- this->get_service().wait(this->get_implementation(), w, ec);
- asio::detail::throw_error(ec, "wait");
- }
-
- /// Wait for the descriptor to become ready to read, ready to write, or to
- /// have pending error conditions.
- /**
- * This function is used to perform a blocking wait for a descriptor to enter
- * a ready to read, write or error condition state.
- *
- * @param w Specifies the desired descriptor state.
- *
- * @param ec Set to indicate what error occurred, if any.
- *
- * @par Example
- * Waiting for a descriptor to become readable.
- * @code
- * asio::posix::stream_descriptor descriptor(io_context);
- * ...
- * asio::error_code ec;
- * descriptor.wait(asio::posix::stream_descriptor::wait_read, ec);
- * @endcode
- */
- asio::error_code wait(wait_type w, asio::error_code& ec)
- {
- return this->get_service().wait(this->get_implementation(), w, ec);
- }
-
- /// Asynchronously wait for the descriptor to become ready to read, ready to
- /// write, or to have pending error conditions.
- /**
- * This function is used to perform an asynchronous wait for a descriptor to
- * enter a ready to read, write or error condition state.
- *
- * @param w Specifies the desired descriptor state.
- *
- * @param handler The handler to be called when the wait operation completes.
- * Copies will be made of the handler as required. The function signature of
- * the handler must be:
- * @code void handler(
- * const asio::error_code& error // Result of operation
- * ); @endcode
- * Regardless of whether the asynchronous operation completes immediately or
- * not, the handler will not be invoked from within this function. Invocation
- * of the handler will be performed in a manner equivalent to using
- * asio::io_context::post().
- *
- * @par Example
- * @code
- * void wait_handler(const asio::error_code& error)
- * {
- * if (!error)
- * {
- * // Wait succeeded.
- * }
- * }
- *
- * ...
- *
- * asio::posix::stream_descriptor descriptor(io_context);
- * ...
- * descriptor.async_wait(
- * asio::posix::stream_descriptor::wait_read,
- * wait_handler);
- * @endcode
- */
- template <typename WaitHandler>
- ASIO_INITFN_RESULT_TYPE(WaitHandler,
- void (asio::error_code))
- async_wait(wait_type w, ASIO_MOVE_ARG(WaitHandler) handler)
- {
- // If you get an error on the following line it means that your handler does
- // not meet the documented type requirements for a WaitHandler.
- ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
-
- return this->get_service().async_wait(this->get_implementation(),
- w, ASIO_MOVE_CAST(WaitHandler)(handler));
- }
-
- protected:
- /// Protected destructor to prevent deletion through this type.
- ~basic_descriptor()
- {
- }
- };
-
- } // namespace posix
- } // namespace asio
-
- #include "asio/detail/pop_options.hpp"
-
- #endif // defined(ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
- // || defined(GENERATING_DOCUMENTATION)
-
- #endif // ASIO_POSIX_BASIC_DESCRIPTOR_HPP
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