1 | // |
2 | // detail/resolve_op.hpp |
3 | // ~~~~~~~~~~~~~~~~~~~~~ |
4 | // |
5 | // Copyright (c) 2003-2015 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_RESOLVE_OP_HPP |
12 | #define BOOST_ASIO_DETAIL_RESOLVE_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_service.hpp> |
21 | #include <boost/asio/ip/basic_resolver_iterator.hpp> |
22 | #include <boost/asio/ip/basic_resolver_query.hpp> |
23 | #include <boost/asio/detail/addressof.hpp> |
24 | #include <boost/asio/detail/bind_handler.hpp> |
25 | #include <boost/asio/detail/fenced_block.hpp> |
26 | #include <boost/asio/detail/handler_alloc_helpers.hpp> |
27 | #include <boost/asio/detail/handler_invoke_helpers.hpp> |
28 | #include <boost/asio/detail/operation.hpp> |
29 | #include <boost/asio/detail/socket_ops.hpp> |
30 | |
31 | #include <boost/asio/detail/push_options.hpp> |
32 | |
33 | namespace boost { |
34 | namespace asio { |
35 | namespace detail { |
36 | |
37 | template <typename Protocol, typename Handler> |
38 | class resolve_op : public operation |
39 | { |
40 | public: |
41 | BOOST_ASIO_DEFINE_HANDLER_PTR(resolve_op); |
42 | |
43 | typedef boost::asio::ip::basic_resolver_query<Protocol> query_type; |
44 | typedef boost::asio::ip::basic_resolver_iterator<Protocol> iterator_type; |
45 | |
46 | resolve_op(socket_ops::weak_cancel_token_type cancel_token, |
47 | const query_type& query, io_service_impl& ios, Handler& handler) |
48 | : operation(&resolve_op::do_complete), |
49 | cancel_token_(cancel_token), |
50 | query_(query), |
51 | io_service_impl_(ios), |
52 | handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)), |
53 | addrinfo_(0) |
54 | { |
55 | } |
56 | |
57 | ~resolve_op() |
58 | { |
59 | if (addrinfo_) |
60 | socket_ops::freeaddrinfo(ai: addrinfo_); |
61 | } |
62 | |
63 | static void do_complete(io_service_impl* owner, operation* base, |
64 | const boost::system::error_code& /*ec*/, |
65 | std::size_t /*bytes_transferred*/) |
66 | { |
67 | // Take ownership of the operation object. |
68 | resolve_op* o(static_cast<resolve_op*>(base)); |
69 | ptr p = { boost::asio::detail::addressof(o->handler_), o, o }; |
70 | |
71 | if (owner && owner != &o->io_service_impl_) |
72 | { |
73 | // The operation is being run on the worker io_service. Time to perform |
74 | // the resolver operation. |
75 | |
76 | // Perform the blocking host resolution operation. |
77 | socket_ops::background_getaddrinfo(cancel_token: o->cancel_token_, |
78 | host: o->query_.host_name().c_str(), service: o->query_.service_name().c_str(), |
79 | hints: o->query_.hints(), result: &o->addrinfo_, ec&: o->ec_); |
80 | |
81 | // Pass operation back to main io_service for completion. |
82 | o->io_service_impl_.post_deferred_completion(o); |
83 | p.v = p.p = 0; |
84 | } |
85 | else |
86 | { |
87 | // The operation has been returned to the main io_service. The completion |
88 | // handler is ready to be delivered. |
89 | |
90 | BOOST_ASIO_HANDLER_COMPLETION((o)); |
91 | |
92 | // Make a copy of the handler so that the memory can be deallocated |
93 | // before the upcall is made. Even if we're not about to make an upcall, |
94 | // a sub-object of the handler may be the true owner of the memory |
95 | // associated with the handler. Consequently, a local copy of the handler |
96 | // is required to ensure that any owning sub-object remains valid until |
97 | // after we have deallocated the memory here. |
98 | detail::binder2<Handler, boost::system::error_code, iterator_type> |
99 | handler(o->handler_, o->ec_, iterator_type()); |
100 | p.h = boost::asio::detail::addressof(handler.handler_); |
101 | if (o->addrinfo_) |
102 | { |
103 | handler.arg2_ = iterator_type::create(o->addrinfo_, |
104 | o->query_.host_name(), o->query_.service_name()); |
105 | } |
106 | p.reset(); |
107 | |
108 | if (owner) |
109 | { |
110 | fenced_block b(fenced_block::half); |
111 | BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, "..." )); |
112 | boost_asio_handler_invoke_helpers::invoke(handler, handler.handler_); |
113 | BOOST_ASIO_HANDLER_INVOCATION_END; |
114 | } |
115 | } |
116 | } |
117 | |
118 | private: |
119 | socket_ops::weak_cancel_token_type cancel_token_; |
120 | query_type query_; |
121 | io_service_impl& io_service_impl_; |
122 | Handler handler_; |
123 | boost::system::error_code ec_; |
124 | boost::asio::detail::addrinfo_type* addrinfo_; |
125 | }; |
126 | |
127 | } // namespace detail |
128 | } // namespace asio |
129 | } // namespace boost |
130 | |
131 | #include <boost/asio/detail/pop_options.hpp> |
132 | |
133 | #endif // BOOST_ASIO_DETAIL_RESOLVE_OP_HPP |
134 | |