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

   1 //
   2 // detail/wait_handler.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2019 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_WAIT_HANDLER_HPP
  12 #define BOOST_ASIO_DETAIL_WAIT_HANDLER_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/handler_work.hpp>
  23 #include <boost/asio/detail/memory.hpp>
  24 #include <boost/asio/detail/wait_op.hpp>
  25
  26 #include <boost/asio/detail/push_options.hpp>
  27
  28 namespace boost {
  29 namespace asio {
  30 namespace detail {
  31
  32 template <typename Handler, typename IoExecutor>
  33 class wait_handler : public wait_op
  34 {
  35 public:
  36   BOOST_ASIO_DEFINE_HANDLER_PTR(wait_handler);
  37
  38   wait_handler(Handler& h, const IoExecutor& ex)
  39     : wait_op(&wait_handler::do_complete),
  40       handler_(BOOST_ASIO_MOVE_CAST(Handler)(h)),
  41       io_executor_(ex)
  42   {
  43     handler_work<Handler, IoExecutor>::start(handler_, io_executor_);
  44   }
  45
  46   static void do_complete(void* owner, operation* base,
  47       const boost::system::error_code& /*ec*/,
  48       std::size_t /*bytes_transferred*/)
  49   {
  50     // Take ownership of the handler object.
  51     wait_handler* h(static_cast<wait_handler*>(base));
  52     ptr p = { boost::asio::detail::addressof(h->handler_), h, h };
  53     handler_work<Handler, IoExecutor> w(h->handler_, h->io_executor_);
  54
  55     BOOST_ASIO_HANDLER_COMPLETION((*h));
  56
  57     // Make a copy of the handler so that the memory can be deallocated before
  58     // the upcall is made. Even if we're not about to make an upcall, a
  59     // sub-object of the handler may be the true owner of the memory associated
  60     // with the handler. Consequently, a local copy of the handler is required
  61     // to ensure that any owning sub-object remains valid until after we have
  62     // deallocated the memory here.
  63     detail::binder1<Handler, boost::system::error_code>
  64       handler(h->handler_, h->ec_);
  65     p.h = boost::asio::detail::addressof(handler.handler_);
  66     p.reset();
  67
  68     // Make the upcall if required.
  69     if (owner)
  70     {
  71       fenced_block b(fenced_block::half);
  72       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_));
  73       w.complete(handler, handler.handler_);
  74       BOOST_ASIO_HANDLER_INVOCATION_END;
  75     }
  76   }
  77
  78 private:
  79   Handler handler_;
  80   IoExecutor io_executor_;
  81 };
  82
  83 } // namespace detail
  84 } // namespace asio
  85 } // namespace boost
  86
  87 #include <boost/asio/detail/pop_options.hpp>
  88
  89 #endif // BOOST_ASIO_DETAIL_WAIT_HANDLER_HPP