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Diffstat (limited to 'boost/asio/detail/resolve_query_op.hpp')
-rw-r--r-- | boost/asio/detail/resolve_query_op.hpp | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/boost/asio/detail/resolve_query_op.hpp b/boost/asio/detail/resolve_query_op.hpp new file mode 100644 index 0000000000..6e5c431941 --- /dev/null +++ b/boost/asio/detail/resolve_query_op.hpp @@ -0,0 +1,136 @@ +// +// detail/resolve_query_op.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2017 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +#ifndef BOOST_ASIO_DETAIL_RESOLVE_QUERY_OP_HPP +#define BOOST_ASIO_DETAIL_RESOLVE_QUERY_OP_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include <boost/asio/detail/config.hpp> +#include <boost/asio/error.hpp> +#include <boost/asio/io_context.hpp> +#include <boost/asio/ip/basic_resolver_query.hpp> +#include <boost/asio/ip/basic_resolver_results.hpp> +#include <boost/asio/detail/bind_handler.hpp> +#include <boost/asio/detail/fenced_block.hpp> +#include <boost/asio/detail/handler_alloc_helpers.hpp> +#include <boost/asio/detail/handler_invoke_helpers.hpp> +#include <boost/asio/detail/memory.hpp> +#include <boost/asio/detail/resolve_op.hpp> +#include <boost/asio/detail/socket_ops.hpp> + +#include <boost/asio/detail/push_options.hpp> + +namespace boost { +namespace asio { +namespace detail { + +template <typename Protocol, typename Handler> +class resolve_query_op : public resolve_op +{ +public: + BOOST_ASIO_DEFINE_HANDLER_PTR(resolve_query_op); + + typedef boost::asio::ip::basic_resolver_query<Protocol> query_type; + typedef boost::asio::ip::basic_resolver_results<Protocol> results_type; + + resolve_query_op(socket_ops::weak_cancel_token_type cancel_token, + const query_type& query, io_context_impl& ioc, Handler& handler) + : resolve_op(&resolve_query_op::do_complete), + cancel_token_(cancel_token), + query_(query), + io_context_impl_(ioc), + handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)), + addrinfo_(0) + { + handler_work<Handler>::start(handler_); + } + + ~resolve_query_op() + { + if (addrinfo_) + socket_ops::freeaddrinfo(addrinfo_); + } + + static void do_complete(void* owner, operation* base, + const boost::system::error_code& /*ec*/, + std::size_t /*bytes_transferred*/) + { + // Take ownership of the operation object. + resolve_query_op* o(static_cast<resolve_query_op*>(base)); + ptr p = { boost::asio::detail::addressof(o->handler_), o, o }; + + if (owner && owner != &o->io_context_impl_) + { + // The operation is being run on the worker io_context. Time to perform + // the resolver operation. + + // Perform the blocking host resolution operation. + socket_ops::background_getaddrinfo(o->cancel_token_, + o->query_.host_name().c_str(), o->query_.service_name().c_str(), + o->query_.hints(), &o->addrinfo_, o->ec_); + + // Pass operation back to main io_context for completion. + o->io_context_impl_.post_deferred_completion(o); + p.v = p.p = 0; + } + else + { + // The operation has been returned to the main io_context. The completion + // handler is ready to be delivered. + + // Take ownership of the operation's outstanding work. + handler_work<Handler> w(o->handler_); + + BOOST_ASIO_HANDLER_COMPLETION((*o)); + + // Make a copy of the handler so that the memory can be deallocated + // before the upcall is made. Even if we're not about to make an upcall, + // a sub-object of the handler may be the true owner of the memory + // associated with the handler. Consequently, a local copy of the handler + // is required to ensure that any owning sub-object remains valid until + // after we have deallocated the memory here. + detail::binder2<Handler, boost::system::error_code, results_type> + handler(o->handler_, o->ec_, results_type()); + p.h = boost::asio::detail::addressof(handler.handler_); + if (o->addrinfo_) + { + handler.arg2_ = results_type::create(o->addrinfo_, + o->query_.host_name(), o->query_.service_name()); + } + p.reset(); + + if (owner) + { + fenced_block b(fenced_block::half); + BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, "...")); + w.complete(handler, handler.handler_); + BOOST_ASIO_HANDLER_INVOCATION_END; + } + } + } + +private: + socket_ops::weak_cancel_token_type cancel_token_; + query_type query_; + io_context_impl& io_context_impl_; + Handler handler_; + boost::asio::detail::addrinfo_type* addrinfo_; +}; + +} // namespace detail +} // namespace asio +} // namespace boost + +#include <boost/asio/detail/pop_options.hpp> + +#endif // BOOST_ASIO_DETAIL_RESOLVE_QUERY_OP_HPP |