boost/asio/detail/io_uring_descriptor_service.hpp
//
// detail/io_uring_descriptor_service.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2024 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 BOOST_ASIO_DETAIL_IO_URING_DESCRIPTOR_SERVICE_HPP
#define BOOST_ASIO_DETAIL_IO_URING_DESCRIPTOR_SERVICE_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include <boost/asio/detail/config.hpp>
#if defined(BOOST_ASIO_HAS_IO_URING)
#include <boost/asio/associated_cancellation_slot.hpp>
#include <boost/asio/buffer.hpp>
#include <boost/asio/cancellation_type.hpp>
#include <boost/asio/execution_context.hpp>
#include <boost/asio/detail/buffer_sequence_adapter.hpp>
#include <boost/asio/detail/descriptor_ops.hpp>
#include <boost/asio/detail/io_uring_descriptor_read_at_op.hpp>
#include <boost/asio/detail/io_uring_descriptor_read_op.hpp>
#include <boost/asio/detail/io_uring_descriptor_write_at_op.hpp>
#include <boost/asio/detail/io_uring_descriptor_write_op.hpp>
#include <boost/asio/detail/io_uring_null_buffers_op.hpp>
#include <boost/asio/detail/io_uring_service.hpp>
#include <boost/asio/detail/io_uring_wait_op.hpp>
#include <boost/asio/detail/memory.hpp>
#include <boost/asio/detail/noncopyable.hpp>
#include <boost/asio/posix/descriptor_base.hpp>
#include <boost/asio/detail/push_options.hpp>
namespace boost {
namespace asio {
namespace detail {
class io_uring_descriptor_service :
public execution_context_service_base<io_uring_descriptor_service>
{
public:
// The native type of a descriptor.
typedef int native_handle_type;
// The implementation type of the descriptor.
class implementation_type
: private boost::asio::detail::noncopyable
{
public:
// Default constructor.
implementation_type()
: descriptor_(-1),
state_(0)
{
}
private:
// Only this service will have access to the internal values.
friend class io_uring_descriptor_service;
// The native descriptor representation.
int descriptor_;
// The current state of the descriptor.
descriptor_ops::state_type state_;
// Per I/O object data used by the io_uring_service.
io_uring_service::per_io_object_data io_object_data_;
};
// Constructor.
BOOST_ASIO_DECL io_uring_descriptor_service(execution_context& context);
// Destroy all user-defined handler objects owned by the service.
BOOST_ASIO_DECL void shutdown();
// Construct a new descriptor implementation.
BOOST_ASIO_DECL void construct(implementation_type& impl);
// Move-construct a new descriptor implementation.
BOOST_ASIO_DECL void move_construct(implementation_type& impl,
implementation_type& other_impl) noexcept;
// Move-assign from another descriptor implementation.
BOOST_ASIO_DECL void move_assign(implementation_type& impl,
io_uring_descriptor_service& other_service,
implementation_type& other_impl);
// Destroy a descriptor implementation.
BOOST_ASIO_DECL void destroy(implementation_type& impl);
// Assign a native descriptor to a descriptor implementation.
BOOST_ASIO_DECL boost::system::error_code assign(implementation_type& impl,
const native_handle_type& native_descriptor,
boost::system::error_code& ec);
// Determine whether the descriptor is open.
bool is_open(const implementation_type& impl) const
{
return impl.descriptor_ != -1;
}
// Destroy a descriptor implementation.
BOOST_ASIO_DECL boost::system::error_code close(implementation_type& impl,
boost::system::error_code& ec);
// Get the native descriptor representation.
native_handle_type native_handle(const implementation_type& impl) const
{
return impl.descriptor_;
}
// Release ownership of the native descriptor representation.
BOOST_ASIO_DECL native_handle_type release(implementation_type& impl);
// Release ownership of the native descriptor representation.
native_handle_type release(implementation_type& impl,
boost::system::error_code& ec)
{
ec = success_ec_;
return release(impl);
}
// Cancel all operations associated with the descriptor.
BOOST_ASIO_DECL boost::system::error_code cancel(implementation_type& impl,
boost::system::error_code& ec);
// Perform an IO control command on the descriptor.
template <typename IO_Control_Command>
boost::system::error_code io_control(implementation_type& impl,
IO_Control_Command& command, boost::system::error_code& ec)
{
descriptor_ops::ioctl(impl.descriptor_, impl.state_,
command.name(), static_cast<ioctl_arg_type*>(command.data()), ec);
BOOST_ASIO_ERROR_LOCATION(ec);
return ec;
}
// Gets the non-blocking mode of the descriptor.
bool non_blocking(const implementation_type& impl) const
{
return (impl.state_ & descriptor_ops::user_set_non_blocking) != 0;
}
// Sets the non-blocking mode of the descriptor.
boost::system::error_code non_blocking(implementation_type& impl,
bool mode, boost::system::error_code& ec)
{
descriptor_ops::set_user_non_blocking(
impl.descriptor_, impl.state_, mode, ec);
BOOST_ASIO_ERROR_LOCATION(ec);
return ec;
}
// Gets the non-blocking mode of the native descriptor implementation.
bool native_non_blocking(const implementation_type& impl) const
{
return (impl.state_ & descriptor_ops::internal_non_blocking) != 0;
}
// Sets the non-blocking mode of the native descriptor implementation.
boost::system::error_code native_non_blocking(implementation_type& impl,
bool mode, boost::system::error_code& ec)
{
descriptor_ops::set_internal_non_blocking(
impl.descriptor_, impl.state_, mode, ec);
BOOST_ASIO_ERROR_LOCATION(ec);
return ec;
}
// Wait for the descriptor to become ready to read, ready to write, or to have
// pending error conditions.
boost::system::error_code wait(implementation_type& impl,
posix::descriptor_base::wait_type w, boost::system::error_code& ec)
{
switch (w)
{
case posix::descriptor_base::wait_read:
descriptor_ops::poll_read(impl.descriptor_, impl.state_, ec);
break;
case posix::descriptor_base::wait_write:
descriptor_ops::poll_write(impl.descriptor_, impl.state_, ec);
break;
case posix::descriptor_base::wait_error:
descriptor_ops::poll_error(impl.descriptor_, impl.state_, ec);
break;
default:
ec = boost::asio::error::invalid_argument;
break;
}
BOOST_ASIO_ERROR_LOCATION(ec);
return ec;
}
// Asynchronously wait for the descriptor to become ready to read, ready to
// write, or to have pending error conditions.
template <typename Handler, typename IoExecutor>
void async_wait(implementation_type& impl,
posix::descriptor_base::wait_type w,
Handler& handler, const IoExecutor& io_ex)
{
bool is_continuation =
boost_asio_handler_cont_helpers::is_continuation(handler);
associated_cancellation_slot_t<Handler> slot
= boost::asio::get_associated_cancellation_slot(handler);
int op_type;
int poll_flags;
switch (w)
{
case posix::descriptor_base::wait_read:
op_type = io_uring_service::read_op;
poll_flags = POLLIN;
break;
case posix::descriptor_base::wait_write:
op_type = io_uring_service::write_op;
poll_flags = POLLOUT;
break;
case posix::descriptor_base::wait_error:
op_type = io_uring_service::except_op;
poll_flags = POLLPRI | POLLERR | POLLHUP;
break;
default:
op_type = -1;
poll_flags = -1;
return;
}
// Allocate and construct an operation to wrap the handler.
typedef io_uring_wait_op<Handler, IoExecutor> op;
typename op::ptr p = { boost::asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(success_ec_, impl.descriptor_,
poll_flags, handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected() && op_type != -1)
{
p.p->cancellation_key_ =
&slot.template emplace<io_uring_op_cancellation>(
&io_uring_service_, &impl.io_object_data_, op_type);
}
BOOST_ASIO_HANDLER_CREATION((io_uring_service_.context(), *p.p,
"descriptor", &impl, impl.descriptor_, "async_wait"));
start_op(impl, op_type, p.p, is_continuation, op_type == -1);
p.v = p.p = 0;
}
// Write some data to the descriptor.
template <typename ConstBufferSequence>
size_t write_some(implementation_type& impl,
const ConstBufferSequence& buffers, boost::system::error_code& ec)
{
typedef buffer_sequence_adapter<boost::asio::const_buffer,
ConstBufferSequence> bufs_type;
size_t n;
if (bufs_type::is_single_buffer)
{
n = descriptor_ops::sync_write1(impl.descriptor_,
impl.state_, bufs_type::first(buffers).data(),
bufs_type::first(buffers).size(), ec);
}
else
{
bufs_type bufs(buffers);
n = descriptor_ops::sync_write(impl.descriptor_, impl.state_,
bufs.buffers(), bufs.count(), bufs.all_empty(), ec);
}
BOOST_ASIO_ERROR_LOCATION(ec);
return n;
}
// Wait until data can be written without blocking.
size_t write_some(implementation_type& impl,
const null_buffers&, boost::system::error_code& ec)
{
// Wait for descriptor to become ready.
descriptor_ops::poll_write(impl.descriptor_, impl.state_, ec);
BOOST_ASIO_ERROR_LOCATION(ec);
return 0;
}
// Start an asynchronous write. The data being sent must be valid for the
// lifetime of the asynchronous operation.
template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
void async_write_some(implementation_type& impl,
const ConstBufferSequence& buffers, Handler& handler,
const IoExecutor& io_ex)
{
bool is_continuation =
boost_asio_handler_cont_helpers::is_continuation(handler);
associated_cancellation_slot_t<Handler> slot
= boost::asio::get_associated_cancellation_slot(handler);
// Allocate and construct an operation to wrap the handler.
typedef io_uring_descriptor_write_op<
ConstBufferSequence, Handler, IoExecutor> op;
typename op::ptr p = { boost::asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(success_ec_, impl.descriptor_,
impl.state_, buffers, handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected())
{
p.p->cancellation_key_ =
&slot.template emplace<io_uring_op_cancellation>(&io_uring_service_,
&impl.io_object_data_, io_uring_service::write_op);
}
BOOST_ASIO_HANDLER_CREATION((io_uring_service_.context(), *p.p,
"descriptor", &impl, impl.descriptor_, "async_write_some"));
start_op(impl, io_uring_service::write_op, p.p, is_continuation,
buffer_sequence_adapter<boost::asio::const_buffer,
ConstBufferSequence>::all_empty(buffers));
p.v = p.p = 0;
}
// Start an asynchronous wait until data can be written without blocking.
template <typename Handler, typename IoExecutor>
void async_write_some(implementation_type& impl,
const null_buffers&, Handler& handler, const IoExecutor& io_ex)
{
bool is_continuation =
boost_asio_handler_cont_helpers::is_continuation(handler);
associated_cancellation_slot_t<Handler> slot
= boost::asio::get_associated_cancellation_slot(handler);
// Allocate and construct an operation to wrap the handler.
typedef io_uring_null_buffers_op<Handler, IoExecutor> op;
typename op::ptr p = { boost::asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(success_ec_, impl.descriptor_, POLLOUT, handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected())
{
p.p->cancellation_key_ =
&slot.template emplace<io_uring_op_cancellation>(&io_uring_service_,
&impl.io_object_data_, io_uring_service::write_op);
}
BOOST_ASIO_HANDLER_CREATION((io_uring_service_.context(),
*p.p, "descriptor", &impl, impl.descriptor_,
"async_write_some(null_buffers)"));
start_op(impl, io_uring_service::write_op, p.p, is_continuation, false);
p.v = p.p = 0;
}
// Write some data to the descriptor at the specified offset.
template <typename ConstBufferSequence>
size_t write_some_at(implementation_type& impl, uint64_t offset,
const ConstBufferSequence& buffers, boost::system::error_code& ec)
{
typedef buffer_sequence_adapter<boost::asio::const_buffer,
ConstBufferSequence> bufs_type;
size_t n;
if (bufs_type::is_single_buffer)
{
n = descriptor_ops::sync_write_at1(impl.descriptor_,
impl.state_, offset, bufs_type::first(buffers).data(),
bufs_type::first(buffers).size(), ec);
}
else
{
bufs_type bufs(buffers);
n = descriptor_ops::sync_write_at(impl.descriptor_, impl.state_,
offset, bufs.buffers(), bufs.count(), bufs.all_empty(), ec);
}
BOOST_ASIO_ERROR_LOCATION(ec);
return n;
}
// Wait until data can be written without blocking.
size_t write_some_at(implementation_type& impl, uint64_t,
const null_buffers& buffers, boost::system::error_code& ec)
{
return write_some(impl, buffers, ec);
}
// Start an asynchronous write at the specified offset. The data being sent
// must be valid for the lifetime of the asynchronous operation.
template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
void async_write_some_at(implementation_type& impl, uint64_t offset,
const ConstBufferSequence& buffers, Handler& handler,
const IoExecutor& io_ex)
{
bool is_continuation =
boost_asio_handler_cont_helpers::is_continuation(handler);
associated_cancellation_slot_t<Handler> slot
= boost::asio::get_associated_cancellation_slot(handler);
// Allocate and construct an operation to wrap the handler.
typedef io_uring_descriptor_write_at_op<
ConstBufferSequence, Handler, IoExecutor> op;
typename op::ptr p = { boost::asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(success_ec_, impl.descriptor_,
impl.state_, offset, buffers, handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected())
{
p.p->cancellation_key_ =
&slot.template emplace<io_uring_op_cancellation>(&io_uring_service_,
&impl.io_object_data_, io_uring_service::write_op);
}
BOOST_ASIO_HANDLER_CREATION((io_uring_service_.context(), *p.p,
"descriptor", &impl, impl.descriptor_, "async_write_some"));
start_op(impl, io_uring_service::write_op, p.p, is_continuation,
buffer_sequence_adapter<boost::asio::const_buffer,
ConstBufferSequence>::all_empty(buffers));
p.v = p.p = 0;
}
// Start an asynchronous wait until data can be written without blocking.
template <typename Handler, typename IoExecutor>
void async_write_some_at(implementation_type& impl,
const null_buffers& buffers, Handler& handler, const IoExecutor& io_ex)
{
return async_write_some(impl, buffers, handler, io_ex);
}
// Read some data from the stream. Returns the number of bytes read.
template <typename MutableBufferSequence>
size_t read_some(implementation_type& impl,
const MutableBufferSequence& buffers, boost::system::error_code& ec)
{
typedef buffer_sequence_adapter<boost::asio::mutable_buffer,
MutableBufferSequence> bufs_type;
size_t n;
if (bufs_type::is_single_buffer)
{
n = descriptor_ops::sync_read1(impl.descriptor_,
impl.state_, bufs_type::first(buffers).data(),
bufs_type::first(buffers).size(), ec);
}
else
{
bufs_type bufs(buffers);
n = descriptor_ops::sync_read(impl.descriptor_, impl.state_,
bufs.buffers(), bufs.count(), bufs.all_empty(), ec);
}
BOOST_ASIO_ERROR_LOCATION(ec);
return n;
}
// Wait until data can be read without blocking.
size_t read_some(implementation_type& impl,
const null_buffers&, boost::system::error_code& ec)
{
// Wait for descriptor to become ready.
descriptor_ops::poll_read(impl.descriptor_, impl.state_, ec);
BOOST_ASIO_ERROR_LOCATION(ec);
return 0;
}
// Start an asynchronous read. The buffer for the data being read must be
// valid for the lifetime of the asynchronous operation.
template <typename MutableBufferSequence,
typename Handler, typename IoExecutor>
void async_read_some(implementation_type& impl,
const MutableBufferSequence& buffers,
Handler& handler, const IoExecutor& io_ex)
{
bool is_continuation =
boost_asio_handler_cont_helpers::is_continuation(handler);
associated_cancellation_slot_t<Handler> slot
= boost::asio::get_associated_cancellation_slot(handler);
// Allocate and construct an operation to wrap the handler.
typedef io_uring_descriptor_read_op<
MutableBufferSequence, Handler, IoExecutor> op;
typename op::ptr p = { boost::asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(success_ec_, impl.descriptor_,
impl.state_, buffers, handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected())
{
p.p->cancellation_key_ =
&slot.template emplace<io_uring_op_cancellation>(&io_uring_service_,
&impl.io_object_data_, io_uring_service::read_op);
}
BOOST_ASIO_HANDLER_CREATION((io_uring_service_.context(), *p.p,
"descriptor", &impl, impl.descriptor_, "async_read_some"));
start_op(impl, io_uring_service::read_op, p.p, is_continuation,
buffer_sequence_adapter<boost::asio::mutable_buffer,
MutableBufferSequence>::all_empty(buffers));
p.v = p.p = 0;
}
// Wait until data can be read without blocking.
template <typename Handler, typename IoExecutor>
void async_read_some(implementation_type& impl,
const null_buffers&, Handler& handler, const IoExecutor& io_ex)
{
bool is_continuation =
boost_asio_handler_cont_helpers::is_continuation(handler);
associated_cancellation_slot_t<Handler> slot
= boost::asio::get_associated_cancellation_slot(handler);
// Allocate and construct an operation to wrap the handler.
typedef io_uring_null_buffers_op<Handler, IoExecutor> op;
typename op::ptr p = { boost::asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(success_ec_, impl.descriptor_, POLLIN, handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected())
{
p.p->cancellation_key_ =
&slot.template emplace<io_uring_op_cancellation>(&io_uring_service_,
&impl.io_object_data_, io_uring_service::read_op);
}
BOOST_ASIO_HANDLER_CREATION((io_uring_service_.context(),
*p.p, "descriptor", &impl, impl.descriptor_,
"async_read_some(null_buffers)"));
start_op(impl, io_uring_service::read_op, p.p, is_continuation, false);
p.v = p.p = 0;
}
// Read some data at the specified offset. Returns the number of bytes read.
template <typename MutableBufferSequence>
size_t read_some_at(implementation_type& impl, uint64_t offset,
const MutableBufferSequence& buffers, boost::system::error_code& ec)
{
typedef buffer_sequence_adapter<boost::asio::mutable_buffer,
MutableBufferSequence> bufs_type;
if (bufs_type::is_single_buffer)
{
return descriptor_ops::sync_read_at1(impl.descriptor_,
impl.state_, offset, bufs_type::first(buffers).data(),
bufs_type::first(buffers).size(), ec);
}
else
{
bufs_type bufs(buffers);
return descriptor_ops::sync_read_at(impl.descriptor_, impl.state_,
offset, bufs.buffers(), bufs.count(), bufs.all_empty(), ec);
}
}
// Wait until data can be read without blocking.
size_t read_some_at(implementation_type& impl, uint64_t,
const null_buffers& buffers, boost::system::error_code& ec)
{
return read_some(impl, buffers, ec);
}
// Start an asynchronous read. The buffer for the data being read must be
// valid for the lifetime of the asynchronous operation.
template <typename MutableBufferSequence,
typename Handler, typename IoExecutor>
void async_read_some_at(implementation_type& impl,
uint64_t offset, const MutableBufferSequence& buffers,
Handler& handler, const IoExecutor& io_ex)
{
bool is_continuation =
boost_asio_handler_cont_helpers::is_continuation(handler);
associated_cancellation_slot_t<Handler> slot
= boost::asio::get_associated_cancellation_slot(handler);
// Allocate and construct an operation to wrap the handler.
typedef io_uring_descriptor_read_at_op<
MutableBufferSequence, Handler, IoExecutor> op;
typename op::ptr p = { boost::asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(success_ec_, impl.descriptor_,
impl.state_, offset, buffers, handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected())
{
p.p->cancellation_key_ =
&slot.template emplace<io_uring_op_cancellation>(&io_uring_service_,
&impl.io_object_data_, io_uring_service::read_op);
}
BOOST_ASIO_HANDLER_CREATION((io_uring_service_.context(), *p.p,
"descriptor", &impl, impl.descriptor_, "async_read_some"));
start_op(impl, io_uring_service::read_op, p.p, is_continuation,
buffer_sequence_adapter<boost::asio::mutable_buffer,
MutableBufferSequence>::all_empty(buffers));
p.v = p.p = 0;
}
// Wait until data can be read without blocking.
template <typename Handler, typename IoExecutor>
void async_read_some_at(implementation_type& impl, uint64_t,
const null_buffers& buffers, Handler& handler, const IoExecutor& io_ex)
{
return async_read_some(impl, buffers, handler, io_ex);
}
private:
// Start the asynchronous operation.
BOOST_ASIO_DECL void start_op(implementation_type& impl, int op_type,
io_uring_operation* op, bool is_continuation, bool noop);
// Helper class used to implement per-operation cancellation
class io_uring_op_cancellation
{
public:
io_uring_op_cancellation(io_uring_service* s,
io_uring_service::per_io_object_data* p, int o)
: io_uring_service_(s),
io_object_data_(p),
op_type_(o)
{
}
void operator()(cancellation_type_t type)
{
if (!!(type &
(cancellation_type::terminal
| cancellation_type::partial
| cancellation_type::total)))
{
io_uring_service_->cancel_ops_by_key(*io_object_data_, op_type_, this);
}
}
private:
io_uring_service* io_uring_service_;
io_uring_service::per_io_object_data* io_object_data_;
int op_type_;
};
// The io_uring_service that performs event demultiplexing for the service.
io_uring_service& io_uring_service_;
// Cached success value to avoid accessing category singleton.
const boost::system::error_code success_ec_;
};
} // namespace detail
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#if defined(BOOST_ASIO_HEADER_ONLY)
# include <boost/asio/detail/impl/io_uring_descriptor_service.ipp>
#endif // defined(BOOST_ASIO_HEADER_ONLY)
#endif // defined(BOOST_ASIO_HAS_IO_URING)
#endif // BOOST_ASIO_DETAIL_IO_URING_DESCRIPTOR_SERVICE_HPP