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

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