| // |
| // posix/descriptor.hpp |
| // ~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2016 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_DESCRIPTOR_HPP |
| #define ASIO_POSIX_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_ENABLE_OLD_SERVICES) |
| |
| #if defined(ASIO_HAS_POSIX_STREAM_DESCRIPTOR) \ |
| || defined(GENERATING_DOCUMENTATION) |
| |
| #include "asio/async_result.hpp" |
| #include "asio/basic_io_object.hpp" |
| #include "asio/detail/handler_type_requirements.hpp" |
| #include "asio/detail/reactive_descriptor_service.hpp" |
| #include "asio/detail/throw_error.hpp" |
| #include "asio/error.hpp" |
| #include "asio/io_context.hpp" |
| #include "asio/posix/descriptor_base.hpp" |
| |
| #if defined(ASIO_HAS_MOVE) |
| # include <utility> |
| #endif // defined(ASIO_HAS_MOVE) |
| |
| #define ASIO_SVC_T asio::detail::reactive_descriptor_service |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace posix { |
| |
| /// Provides POSIX descriptor functionality. |
| /** |
| * The posix::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. |
| */ |
| class descriptor |
| : ASIO_SVC_ACCESS basic_io_object<ASIO_SVC_T>, |
| public descriptor_base |
| { |
| public: |
| /// The type of the executor associated with the object. |
| typedef io_context::executor_type executor_type; |
| |
| /// The native representation of a descriptor. |
| #if defined(GENERATING_DOCUMENTATION) |
| typedef implementation_defined native_handle_type; |
| #else |
| typedef ASIO_SVC_T::native_handle_type native_handle_type; |
| #endif |
| |
| /// A descriptor is always the lowest layer. |
| typedef descriptor lowest_layer_type; |
| |
| /// Construct a 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 descriptor(asio::io_context& io_context) |
| : basic_io_object<ASIO_SVC_T>(io_context) |
| { |
| } |
| |
| /// Construct a 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. |
| */ |
| descriptor(asio::io_context& io_context, |
| const native_handle_type& native_descriptor) |
| : basic_io_object<ASIO_SVC_T>(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 descriptor from another. |
| /** |
| * This constructor moves a descriptor from one object to another. |
| * |
| * @param other The other 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 descriptor(io_context&) constructor. |
| */ |
| descriptor(descriptor&& other) |
| : basic_io_object<ASIO_SVC_T>(std::move(other)) |
| { |
| } |
| |
| /// Move-assign a descriptor from another. |
| /** |
| * This assignment operator moves a descriptor from one object to another. |
| * |
| * @param other The other 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 descriptor(io_context&) constructor. |
| */ |
| descriptor& operator=(descriptor&& other) |
| { |
| basic_io_object<ASIO_SVC_T>::operator=(std::move(other)); |
| return *this; |
| } |
| #endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) |
| |
| #if !defined(ASIO_NO_DEPRECATED) |
| /// (Deprecated: Use get_executor().) Get the io_context associated with the |
| /// object. |
| /** |
| * This function may be used to obtain the io_context object that the I/O |
| * object uses to dispatch handlers for asynchronous operations. |
| * |
| * @return A reference to the io_context object that the I/O object will use |
| * to dispatch handlers. Ownership is not transferred to the caller. |
| */ |
| asio::io_context& get_io_context() |
| { |
| return basic_io_object<ASIO_SVC_T>::get_io_context(); |
| } |
| |
| /// (Deprecated: Use get_executor().) Get the io_context associated with the |
| /// object. |
| /** |
| * This function may be used to obtain the io_context object that the I/O |
| * object uses to dispatch handlers for asynchronous operations. |
| * |
| * @return A reference to the io_context object that the I/O object will use |
| * to dispatch handlers. Ownership is not transferred to the caller. |
| */ |
| asio::io_context& get_io_service() |
| { |
| return basic_io_object<ASIO_SVC_T>::get_io_service(); |
| } |
| #endif // !defined(ASIO_NO_DEPRECATED) |
| |
| /// Get the executor associated with the object. |
| executor_type get_executor() ASIO_NOEXCEPT |
| { |
| return basic_io_object<ASIO_SVC_T>::get_executor(); |
| } |
| |
| /// Get a reference to the lowest layer. |
| /** |
| * This function returns a reference to the lowest layer in a stack of |
| * layers. Since a 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 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_SYNC_OP_VOID assign(const native_handle_type& native_descriptor, |
| asio::error_code& ec) |
| { |
| this->get_service().assign( |
| this->get_implementation(), native_descriptor, ec); |
| ASIO_SYNC_OP_VOID_RETURN(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_SYNC_OP_VOID close(asio::error_code& ec) |
| { |
| this->get_service().close(this->get_implementation(), ec); |
| ASIO_SYNC_OP_VOID_RETURN(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_SYNC_OP_VOID cancel(asio::error_code& ec) |
| { |
| this->get_service().cancel(this->get_implementation(), ec); |
| ASIO_SYNC_OP_VOID_RETURN(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_SYNC_OP_VOID io_control(IoControlCommand& command, |
| asio::error_code& ec) |
| { |
| this->get_service().io_control(this->get_implementation(), command, ec); |
| ASIO_SYNC_OP_VOID_RETURN(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_SYNC_OP_VOID non_blocking( |
| bool mode, asio::error_code& ec) |
| { |
| this->get_service().non_blocking(this->get_implementation(), mode, ec); |
| ASIO_SYNC_OP_VOID_RETURN(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_SYNC_OP_VOID native_non_blocking( |
| bool mode, asio::error_code& ec) |
| { |
| this->get_service().native_non_blocking( |
| this->get_implementation(), mode, ec); |
| ASIO_SYNC_OP_VOID_RETURN(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_SYNC_OP_VOID wait(wait_type w, asio::error_code& ec) |
| { |
| this->get_service().wait(this->get_implementation(), w, ec); |
| ASIO_SYNC_OP_VOID_RETURN(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; |
| |
| async_completion<WaitHandler, |
| void (asio::error_code)> init(handler); |
| |
| this->get_service().async_wait( |
| this->get_implementation(), w, init.completion_handler); |
| |
| return init.result.get(); |
| } |
| |
| protected: |
| /// Protected destructor to prevent deletion through this type. |
| /** |
| * This function destroys the descriptor, cancelling any outstanding |
| * asynchronous wait operations associated with the descriptor as if by |
| * calling @c cancel. |
| */ |
| ~descriptor() |
| { |
| } |
| }; |
| |
| } // namespace posix |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #undef ASIO_SVC_T |
| |
| #endif // defined(ASIO_HAS_POSIX_STREAM_DESCRIPTOR) |
| // || defined(GENERATING_DOCUMENTATION) |
| |
| #endif // !defined(ASIO_ENABLE_OLD_SERVICES) |
| |
| #endif // ASIO_POSIX_DESCRIPTOR_HPP |