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//
// 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
|