ceph/src/boost/boost/asio/detail/reactive_null_buffers_op.hpp

   1 //
   2 // detail/reactive_null_buffers_op.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #ifndef BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP
  12 #define BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19 #include <boost/asio/detail/bind_handler.hpp>
  20 #include <boost/asio/detail/fenced_block.hpp>
  21 #include <boost/asio/detail/handler_alloc_helpers.hpp>
  22 #include <boost/asio/detail/handler_invoke_helpers.hpp>
  23 #include <boost/asio/detail/handler_work.hpp>
  24 #include <boost/asio/detail/memory.hpp>
  25 #include <boost/asio/detail/reactor_op.hpp>
  26
  27 #include <boost/asio/detail/push_options.hpp>
  28
  29 namespace boost {
  30 namespace asio {
  31 namespace detail {
  32
  33 template <typename Handler, typename IoExecutor>
  34 class reactive_null_buffers_op : public reactor_op
  35 {
  36 public:
  37   BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_null_buffers_op);
  38
  39   reactive_null_buffers_op(const boost::system::error_code& success_ec,
  40       Handler& handler, const IoExecutor& io_ex)
  41     : reactor_op(success_ec, &reactive_null_buffers_op::do_perform,
  42         &reactive_null_buffers_op::do_complete),
  43       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
  44       work_(handler_, io_ex)
  45   {
  46   }
  47
  48   static status do_perform(reactor_op*)
  49   {
  50     return done;
  51   }
  52
  53   static void do_complete(void* owner, operation* base,
  54       const boost::system::error_code& /*ec*/,
  55       std::size_t /*bytes_transferred*/)
  56   {
  57     // Take ownership of the handler object.
  58     reactive_null_buffers_op* o(static_cast<reactive_null_buffers_op*>(base));
  59     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
  60
  61     BOOST_ASIO_HANDLER_COMPLETION((*o));
  62
  63     // Take ownership of the operation's outstanding work.
  64     handler_work<Handler, IoExecutor> w(
  65         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
  66           o->work_));
  67
  68     // Make a copy of the handler so that the memory can be deallocated before
  69     // the upcall is made. Even if we're not about to make an upcall, a
  70     // sub-object of the handler may be the true owner of the memory associated
  71     // with the handler. Consequently, a local copy of the handler is required
  72     // to ensure that any owning sub-object remains valid until after we have
  73     // deallocated the memory here.
  74     detail::binder2<Handler, boost::system::error_code, std::size_t>
  75       handler(o->handler_, o->ec_, o->bytes_transferred_);
  76     p.h = boost::asio::detail::addressof(handler.handler_);
  77     p.reset();
  78
  79     // Make the upcall if required.
  80     if (owner)
  81     {
  82       fenced_block b(fenced_block::half);
  83       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
  84       w.complete(handler, handler.handler_);
  85       BOOST_ASIO_HANDLER_INVOCATION_END;
  86     }
  87   }
  88
  89 private:
  90   Handler handler_;
  91   handler_work<Handler, IoExecutor> work_;
  92 };
  93
  94 } // namespace detail
  95 } // namespace asio
  96 } // namespace boost
  97
  98 #include <boost/asio/detail/pop_options.hpp>
  99
 100 #endif // BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP