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- //
- // windows/basic_overlapped_handle.hpp
- // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2019 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_WINDOWS_BASIC_OVERLAPPED_HANDLE_HPP
- #define ASIO_WINDOWS_BASIC_OVERLAPPED_HANDLE_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_WINDOWS_RANDOM_ACCESS_HANDLE) \
- || defined(ASIO_HAS_WINDOWS_STREAM_HANDLE) \
- || defined(GENERATING_DOCUMENTATION)
-
- #include <cstddef>
- #include "asio/async_result.hpp"
- #include "asio/detail/io_object_impl.hpp"
- #include "asio/detail/throw_error.hpp"
- #include "asio/detail/win_iocp_handle_service.hpp"
- #include "asio/error.hpp"
- #include "asio/execution_context.hpp"
- #include "asio/executor.hpp"
-
- #if defined(ASIO_HAS_MOVE)
- # include <utility>
- #endif // defined(ASIO_HAS_MOVE)
-
- #include "asio/detail/push_options.hpp"
-
- namespace asio {
- namespace windows {
-
- /// Provides Windows handle functionality for objects that support
- /// overlapped I/O.
- /**
- * The windows::overlapped_handle class provides the ability to wrap a Windows
- * handle. The underlying object referred to by the handle must support
- * overlapped I/O.
- *
- * @par Thread Safety
- * @e Distinct @e objects: Safe.@n
- * @e Shared @e objects: Unsafe.
- */
- template <typename Executor = executor>
- class basic_overlapped_handle
- {
- public:
- /// The type of the executor associated with the object.
- typedef Executor executor_type;
-
- /// The native representation of a handle.
- #if defined(GENERATING_DOCUMENTATION)
- typedef implementation_defined native_handle_type;
- #else
- typedef asio::detail::win_iocp_handle_service::native_handle_type
- native_handle_type;
- #endif
-
- /// An overlapped_handle is always the lowest layer.
- typedef basic_overlapped_handle lowest_layer_type;
-
- /// Construct an overlapped handle without opening it.
- /**
- * This constructor creates an overlapped handle without opening it.
- *
- * @param ex The I/O executor that the overlapped handle will use, by default,
- * to dispatch handlers for any asynchronous operations performed on the
- * overlapped handle.
- */
- explicit basic_overlapped_handle(const executor_type& ex)
- : impl_(ex)
- {
- }
-
- /// Construct an overlapped handle without opening it.
- /**
- * This constructor creates an overlapped handle without opening it.
- *
- * @param context An execution context which provides the I/O executor that
- * the overlapped handle will use, by default, to dispatch handlers for any
- * asynchronous operations performed on the overlapped handle.
- */
- template <typename ExecutionContext>
- explicit basic_overlapped_handle(ExecutionContext& context,
- typename enable_if<
- is_convertible<ExecutionContext&, execution_context&>::value,
- basic_overlapped_handle
- >::type* = 0)
- : impl_(context)
- {
- }
-
- /// Construct an overlapped handle on an existing native handle.
- /**
- * This constructor creates an overlapped handle object to hold an existing
- * native handle.
- *
- * @param ex The I/O executor that the overlapped handle will use, by default,
- * to dispatch handlers for any asynchronous operations performed on the
- * overlapped handle.
- *
- * @param native_handle The new underlying handle implementation.
- *
- * @throws asio::system_error Thrown on failure.
- */
- basic_overlapped_handle(const executor_type& ex,
- const native_handle_type& native_handle)
- : impl_(ex)
- {
- asio::error_code ec;
- impl_.get_service().assign(impl_.get_implementation(), native_handle, ec);
- asio::detail::throw_error(ec, "assign");
- }
-
- /// Construct an overlapped handle on an existing native handle.
- /**
- * This constructor creates an overlapped handle object to hold an existing
- * native handle.
- *
- * @param context An execution context which provides the I/O executor that
- * the overlapped handle will use, by default, to dispatch handlers for any
- * asynchronous operations performed on the overlapped handle.
- *
- * @param native_handle The new underlying handle implementation.
- *
- * @throws asio::system_error Thrown on failure.
- */
- template <typename ExecutionContext>
- basic_overlapped_handle(ExecutionContext& context,
- const native_handle_type& native_handle,
- typename enable_if<
- is_convertible<ExecutionContext&, execution_context&>::value
- >::type* = 0)
- : impl_(context)
- {
- asio::error_code ec;
- impl_.get_service().assign(impl_.get_implementation(), native_handle, ec);
- asio::detail::throw_error(ec, "assign");
- }
-
- #if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
- /// Move-construct an overlapped handle from another.
- /**
- * This constructor moves a handle from one object to another.
- *
- * @param other The other overlapped handle 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 overlapped_handle(const executor_type&)
- * constructor.
- */
- basic_overlapped_handle(basic_overlapped_handle&& other)
- : impl_(std::move(other.impl_))
- {
- }
-
- /// Move-assign an overlapped handle from another.
- /**
- * This assignment operator moves a handle from one object to another.
- *
- * @param other The other overlapped handle 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 overlapped_handle(const executor_type&)
- * constructor.
- */
- basic_overlapped_handle& operator=(basic_overlapped_handle&& other)
- {
- impl_ = std::move(other.impl_);
- return *this;
- }
- #endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
-
- /// Get the executor associated with the object.
- executor_type get_executor() ASIO_NOEXCEPT
- {
- return impl_.get_executor();
- }
-
- /// Get a reference to the lowest layer.
- /**
- * This function returns a reference to the lowest layer in a stack of
- * layers. Since an overlapped_handle 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 an overlapped_handle 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 handle to the handle.
- /*
- * This function opens the handle to hold an existing native handle.
- *
- * @param handle A native handle.
- *
- * @throws asio::system_error Thrown on failure.
- */
- void assign(const native_handle_type& handle)
- {
- asio::error_code ec;
- impl_.get_service().assign(impl_.get_implementation(), handle, ec);
- asio::detail::throw_error(ec, "assign");
- }
-
- /// Assign an existing native handle to the handle.
- /*
- * This function opens the handle to hold an existing native handle.
- *
- * @param handle A native handle.
- *
- * @param ec Set to indicate what error occurred, if any.
- */
- ASIO_SYNC_OP_VOID assign(const native_handle_type& handle,
- asio::error_code& ec)
- {
- impl_.get_service().assign(impl_.get_implementation(), handle, ec);
- ASIO_SYNC_OP_VOID_RETURN(ec);
- }
-
- /// Determine whether the handle is open.
- bool is_open() const
- {
- return impl_.get_service().is_open(impl_.get_implementation());
- }
-
- /// Close the handle.
- /**
- * This function is used to close the handle. 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.
- */
- void close()
- {
- asio::error_code ec;
- impl_.get_service().close(impl_.get_implementation(), ec);
- asio::detail::throw_error(ec, "close");
- }
-
- /// Close the handle.
- /**
- * This function is used to close the handle. 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.
- */
- ASIO_SYNC_OP_VOID close(asio::error_code& ec)
- {
- impl_.get_service().close(impl_.get_implementation(), ec);
- ASIO_SYNC_OP_VOID_RETURN(ec);
- }
-
- /// Get the native handle representation.
- /**
- * This function may be used to obtain the underlying representation of the
- * handle. This is intended to allow access to native handle functionality
- * that is not otherwise provided.
- */
- native_handle_type native_handle()
- {
- return impl_.get_service().native_handle(impl_.get_implementation());
- }
-
- /// Cancel all asynchronous operations associated with the handle.
- /**
- * 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;
- impl_.get_service().cancel(impl_.get_implementation(), ec);
- asio::detail::throw_error(ec, "cancel");
- }
-
- /// Cancel all asynchronous operations associated with the handle.
- /**
- * 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)
- {
- impl_.get_service().cancel(impl_.get_implementation(), ec);
- ASIO_SYNC_OP_VOID_RETURN(ec);
- }
-
- protected:
- /// Protected destructor to prevent deletion through this type.
- /**
- * This function destroys the handle, cancelling any outstanding asynchronous
- * wait operations associated with the handle as if by calling @c cancel.
- */
- ~basic_overlapped_handle()
- {
- }
-
- asio::detail::io_object_impl<
- asio::detail::win_iocp_handle_service, Executor> impl_;
-
- private:
- // Disallow copying and assignment.
- basic_overlapped_handle(const basic_overlapped_handle&) ASIO_DELETED;
- basic_overlapped_handle& operator=(
- const basic_overlapped_handle&) ASIO_DELETED;
- };
-
- } // namespace windows
- } // namespace asio
-
- #include "asio/detail/pop_options.hpp"
-
- #endif // defined(ASIO_HAS_WINDOWS_RANDOM_ACCESS_HANDLE)
- // || defined(ASIO_HAS_WINDOWS_STREAM_HANDLE)
- // || defined(GENERATING_DOCUMENTATION)
-
- #endif // ASIO_WINDOWS_BASIC_OVERLAPPED_HANDLE_HPP
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