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

   1 //
   2 // detail/reactive_null_buffers_op.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2017 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/fenced_block.hpp>
  20 #include <boost/asio/detail/handler_alloc_helpers.hpp>
  21 #include <boost/asio/detail/handler_invoke_helpers.hpp>
  22 #include <boost/asio/detail/memory.hpp>
  23 #include <boost/asio/detail/reactor_op.hpp>
  24
  25 #include <boost/asio/detail/push_options.hpp>
  26
  27 namespace boost {
  28 namespace asio {
  29 namespace detail {
  30
  31 template <typename Handler>
  32 class reactive_null_buffers_op : public reactor_op
  33 {
  34 public:
  35   BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_null_buffers_op);
  36
  37   reactive_null_buffers_op(Handler& handler)
  38     : reactor_op(&reactive_null_buffers_op::do_perform,
  39         &reactive_null_buffers_op::do_complete),
  40       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler))
  41   {
  42     handler_work<Handler>::start(handler_);
  43   }
  44
  45   static status do_perform(reactor_op*)
  46   {
  47     return done;
  48   }
  49
  50   static void do_complete(void* owner, operation* base,
  51       const boost::system::error_code& /*ec*/,
  52       std::size_t /*bytes_transferred*/)
  53   {
  54     // Take ownership of the handler object.
  55     reactive_null_buffers_op* o(static_cast<reactive_null_buffers_op*>(base));
  56     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
  57     handler_work<Handler> w(o->handler_);
  58
  59     BOOST_ASIO_HANDLER_COMPLETION((*o));
  60
  61     // Make a copy of the handler so that the memory can be deallocated before
  62     // the upcall is made. Even if we're not about to make an upcall, a
  63     // sub-object of the handler may be the true owner of the memory associated
  64     // with the handler. Consequently, a local copy of the handler is required
  65     // to ensure that any owning sub-object remains valid until after we have
  66     // deallocated the memory here.
  67     detail::binder2<Handler, boost::system::error_code, std::size_t>
  68       handler(o->handler_, o->ec_, o->bytes_transferred_);
  69     p.h = boost::asio::detail::addressof(handler.handler_);
  70     p.reset();
  71
  72     // Make the upcall if required.
  73     if (owner)
  74     {
  75       fenced_block b(fenced_block::half);
  76       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
  77       w.complete(handler, handler.handler_);
  78       BOOST_ASIO_HANDLER_INVOCATION_END;
  79     }
  80   }
  81
  82 private:
  83   Handler handler_;
  84 };
  85
  86 } // namespace detail
  87 } // namespace asio
  88 } // namespace boost
  89
  90 #include <boost/asio/detail/pop_options.hpp>
  91
  92 #endif // BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP