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

   1 //
   2 // detail/executor_op.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_EXECUTOR_OP_HPP
  12 #define BOOST_ASIO_DETAIL_EXECUTOR_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/scheduler_operation.hpp>
  23
  24 #include <boost/asio/detail/push_options.hpp>
  25
  26 namespace boost {
  27 namespace asio {
  28 namespace detail {
  29
  30 template <typename Handler, typename Alloc,
  31     typename Operation = scheduler_operation>
  32 class executor_op : public Operation
  33 {
  34 public:
  35   BOOST_ASIO_DEFINE_HANDLER_ALLOCATOR_PTR(executor_op);
  36
  37   template <typename H>
  38   executor_op(BOOST_ASIO_MOVE_ARG(H) h, const Alloc& allocator)
  39     : Operation(&executor_op::do_complete),
  40       handler_(BOOST_ASIO_MOVE_CAST(H)(h)),
  41       allocator_(allocator)
  42   {
  43   }
  44
  45   static void do_complete(void* owner, Operation* base,
  46       const boost::system::error_code& /*ec*/,
  47       std::size_t /*bytes_transferred*/)
  48   {
  49     // Take ownership of the handler object.
  50     executor_op* o(static_cast<executor_op*>(base));
  51     Alloc allocator(o->allocator_);
  52     ptr p = { detail::addressof(allocator), o, o };
  53
  54     BOOST_ASIO_HANDLER_COMPLETION((*o));
  55
  56     // Make a copy of the handler so that the memory can be deallocated before
  57     // the upcall is made. Even if we're not about to make an upcall, a
  58     // sub-object of the handler may be the true owner of the memory associated
  59     // with the handler. Consequently, a local copy of the handler is required
  60     // to ensure that any owning sub-object remains valid until after we have
  61     // deallocated the memory here.
  62     Handler handler(BOOST_ASIO_MOVE_CAST(Handler)(o->handler_));
  63     p.reset();
  64
  65     // Make the upcall if required.
  66     if (owner)
  67     {
  68       fenced_block b(fenced_block::half);
  69       BOOST_ASIO_HANDLER_INVOCATION_BEGIN(());
  70       boost_asio_handler_invoke_helpers::invoke(handler, handler);
  71       BOOST_ASIO_HANDLER_INVOCATION_END;
  72     }
  73   }
  74
  75 private:
  76   Handler handler_;
  77   Alloc allocator_;
  78 };
  79
  80 } // namespace detail
  81 } // namespace asio
  82 } // namespace boost
  83
  84 #include <boost/asio/detail/pop_options.hpp>
  85
  86 #endif // BOOST_ASIO_DETAIL_EXECUTOR_OP_HPP