asio/detail/io_uring_wait_op.hpp

0001 //
0002 // detail/io_uring_wait_op.hpp
0003 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~
0004 //
0005 // Copyright (c) 2003-2023 Christopher M. Kohlhoff (chris at kohlhoff dot com)
0006 //
0007 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0008 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0009 //
0010
0011 #ifndef BOOST_ASIO_DETAIL_IO_URING_WAIT_OP_HPP
0012 #define BOOST_ASIO_DETAIL_IO_URING_WAIT_OP_HPP
0013
0014 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
0015 # pragma once
0016 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
0017
0018 #include <boost/asio/detail/config.hpp>
0019 #include <boost/asio/detail/bind_handler.hpp>
0020 #include <boost/asio/detail/fenced_block.hpp>
0021 #include <boost/asio/detail/handler_alloc_helpers.hpp>
0022 #include <boost/asio/detail/handler_work.hpp>
0023 #include <boost/asio/detail/io_uring_operation.hpp>
0024 #include <boost/asio/detail/memory.hpp>
0025
0026 #include <boost/asio/detail/push_options.hpp>
0027
0028 namespace boost {
0029 namespace asio {
0030 namespace detail {
0031
0032 template <typename Handler, typename IoExecutor>
0033 class io_uring_wait_op : public io_uring_operation
0034 {
0035 public:
0036   BOOST_ASIO_DEFINE_HANDLER_PTR(io_uring_wait_op);
0037
0038   io_uring_wait_op(const boost::system::error_code& success_ec, int descriptor,
0039       int poll_flags, Handler& handler, const IoExecutor& io_ex)
0040     : io_uring_operation(success_ec, &io_uring_wait_op::do_prepare,
0041         &io_uring_wait_op::do_perform, &io_uring_wait_op::do_complete),
0042       handler_(static_cast<Handler&&>(handler)),
0043       work_(handler_, io_ex),
0044       descriptor_(descriptor),
0045       poll_flags_(poll_flags)
0046   {
0047   }
0048
0049   static void do_prepare(io_uring_operation* base, ::io_uring_sqe* sqe)
0050   {
0051     BOOST_ASIO_ASSUME(base != 0);
0052     io_uring_wait_op* o(static_cast<io_uring_wait_op*>(base));
0053
0054     ::io_uring_prep_poll_add(sqe, o->descriptor_, o->poll_flags_);
0055   }
0056
0057   static bool do_perform(io_uring_operation*, bool after_completion)
0058   {
0059     return after_completion;
0060   }
0061
0062   static void do_complete(void* owner, operation* base,
0063       const boost::system::error_code& /*ec*/,
0064       std::size_t /*bytes_transferred*/)
0065   {
0066     // Take ownership of the handler object.
0067     BOOST_ASIO_ASSUME(base != 0);
0068     io_uring_wait_op* o(static_cast<io_uring_wait_op*>(base));
0069     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
0070
0071     BOOST_ASIO_HANDLER_COMPLETION((*o));
0072
0073     // Take ownership of the operation's outstanding work.
0074     handler_work<Handler, IoExecutor> w(
0075         static_cast<handler_work<Handler, IoExecutor>&&>(
0076           o->work_));
0077
0078     BOOST_ASIO_ERROR_LOCATION(o->ec_);
0079
0080     // Make a copy of the handler so that the memory can be deallocated before
0081     // the upcall is made. Even if we're not about to make an upcall, a
0082     // sub-object of the handler may be the true owner of the memory associated
0083     // with the handler. Consequently, a local copy of the handler is required
0084     // to ensure that any owning sub-object remains valid until after we have
0085     // deallocated the memory here.
0086     detail::binder1<Handler, boost::system::error_code>
0087       handler(o->handler_, o->ec_);
0088     p.h = boost::asio::detail::addressof(handler.handler_);
0089     p.reset();
0090
0091     // Make the upcall if required.
0092     if (owner)
0093     {
0094       fenced_block b(fenced_block::half);
0095       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
0096       w.complete(handler, handler.handler_);
0097       BOOST_ASIO_HANDLER_INVOCATION_END;
0098     }
0099   }
0100
0101 private:
0102   Handler handler_;
0103   handler_work<Handler, IoExecutor> work_;
0104   int descriptor_;
0105   int poll_flags_;
0106 };
0107
0108 } // namespace detail
0109 } // namespace asio
0110 } // namespace boost
0111
0112 #include <boost/asio/detail/pop_options.hpp>
0113
0114 #endif // BOOST_ASIO_DETAIL_IO_URING_WAIT_OP_HPP