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

   1 //
   2 // detail/resolve_endpoint_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_RESOLVER_ENDPOINT_OP_HPP
  12 #define BOOST_ASIO_DETAIL_RESOLVER_ENDPOINT_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/resolve_op.hpp>
  26 #include <boost/asio/detail/socket_ops.hpp>
  27 #include <boost/asio/error.hpp>
  28 #include <boost/asio/ip/basic_resolver_results.hpp>
  29
  30 #if defined(BOOST_ASIO_HAS_IOCP)
  31 # include <boost/asio/detail/win_iocp_io_context.hpp>
  32 #else // defined(BOOST_ASIO_HAS_IOCP)
  33 # include <boost/asio/detail/scheduler.hpp>
  34 #endif // defined(BOOST_ASIO_HAS_IOCP)
  35
  36 #include <boost/asio/detail/push_options.hpp>
  37
  38 namespace boost {
  39 namespace asio {
  40 namespace detail {
  41
  42 template <typename Protocol, typename Handler, typename IoExecutor>
  43 class resolve_endpoint_op : public resolve_op
  44 {
  45 public:
  46   BOOST_ASIO_DEFINE_HANDLER_PTR(resolve_endpoint_op);
  47
  48   typedef typename Protocol::endpoint endpoint_type;
  49   typedef boost::asio::ip::basic_resolver_results<Protocol> results_type;
  50
  51 #if defined(BOOST_ASIO_HAS_IOCP)
  52   typedef class win_iocp_io_context scheduler_impl;
  53 #else
  54   typedef class scheduler scheduler_impl;
  55 #endif
  56
  57   resolve_endpoint_op(socket_ops::weak_cancel_token_type cancel_token,
  58       const endpoint_type& endpoint, scheduler_impl& sched,
  59       Handler& handler, const IoExecutor& io_ex)
  60     : resolve_op(&resolve_endpoint_op::do_complete),
  61       cancel_token_(cancel_token),
  62       endpoint_(endpoint),
  63       scheduler_(sched),
  64       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
  65       work_(handler_, io_ex)
  66   {
  67   }
  68
  69   static void do_complete(void* owner, operation* base,
  70       const boost::system::error_code& /*ec*/,
  71       std::size_t /*bytes_transferred*/)
  72   {
  73     // Take ownership of the operation object.
  74     resolve_endpoint_op* o(static_cast<resolve_endpoint_op*>(base));
  75     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
  76
  77     if (owner && owner != &o->scheduler_)
  78     {
  79       // The operation is being run on the worker io_context. Time to perform
  80       // the resolver operation.
  81
  82       // Perform the blocking endpoint resolution operation.
  83       char host_name[NI_MAXHOST] = "";
  84       char service_name[NI_MAXSERV] = "";
  85       socket_ops::background_getnameinfo(o->cancel_token_, o->endpoint_.data(),
  86           o->endpoint_.size(), host_name, NI_MAXHOST, service_name, NI_MAXSERV,
  87           o->endpoint_.protocol().type(), o->ec_);
  88       o->results_ = results_type::create(o->endpoint_, host_name, service_name);
  89
  90       // Pass operation back to main io_context for completion.
  91       o->scheduler_.post_deferred_completion(o);
  92       p.v = p.p = 0;
  93     }
  94     else
  95     {
  96       // The operation has been returned to the main io_context. The completion
  97       // handler is ready to be delivered.
  98
  99       BOOST_ASIO_HANDLER_COMPLETION((*o));
 100
 101       // Take ownership of the operation's outstanding work.
 102       handler_work<Handler, IoExecutor> w(
 103           BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
 104             o->work_));
 105
 106       // Make a copy of the handler so that the memory can be deallocated
 107       // before the upcall is made. Even if we're not about to make an upcall,
 108       // a sub-object of the handler may be the true owner of the memory
 109       // associated with the handler. Consequently, a local copy of the handler
 110       // is required to ensure that any owning sub-object remains valid until
 111       // after we have deallocated the memory here.
 112       detail::binder2<Handler, boost::system::error_code, results_type>
 113         handler(o->handler_, o->ec_, o->results_);
 114       p.h = boost::asio::detail::addressof(handler.handler_);
 115       p.reset();
 116
 117       if (owner)
 118       {
 119         fenced_block b(fenced_block::half);
 120         BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, "..."));
 121         w.complete(handler, handler.handler_);
 122         BOOST_ASIO_HANDLER_INVOCATION_END;
 123       }
 124     }
 125   }
 126
 127 private:
 128   socket_ops::weak_cancel_token_type cancel_token_;
 129   endpoint_type endpoint_;
 130   scheduler_impl& scheduler_;
 131   Handler handler_;
 132   handler_work<Handler, IoExecutor> work_;
 133   results_type results_;
 134 };
 135
 136 } // namespace detail
 137 } // namespace asio
 138 } // namespace boost
 139
 140 #include <boost/asio/detail/pop_options.hpp>
 141
 142 #endif // BOOST_ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP