| // |
| // detail/resolve_query_op.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2016 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 ASIO_DETAIL_RESOLVE_QUERY_OP_HPP |
| #define ASIO_DETAIL_RESOLVE_QUERY_OP_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include "asio/detail/config.hpp" |
| #include "asio/error.hpp" |
| #include "asio/io_context.hpp" |
| #include "asio/ip/basic_resolver_query.hpp" |
| #include "asio/ip/basic_resolver_results.hpp" |
| #include "asio/detail/bind_handler.hpp" |
| #include "asio/detail/fenced_block.hpp" |
| #include "asio/detail/handler_alloc_helpers.hpp" |
| #include "asio/detail/handler_invoke_helpers.hpp" |
| #include "asio/detail/memory.hpp" |
| #include "asio/detail/resolve_op.hpp" |
| #include "asio/detail/socket_ops.hpp" |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace detail { |
| |
| template <typename Protocol, typename Handler> |
| class resolve_query_op : public resolve_op |
| { |
| public: |
| ASIO_DEFINE_HANDLER_PTR(resolve_query_op); |
| |
| typedef asio::ip::basic_resolver_query<Protocol> query_type; |
| typedef 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_(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 asio::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 = { asio::detail::addressof(o->handler_), o, o }; |
| handler_work<Handler> w(o->handler_); |
| |
| 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. |
| |
| 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, asio::error_code, results_type> |
| handler(o->handler_, o->ec_, results_type()); |
| p.h = 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); |
| ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, "...")); |
| w.complete(handler, handler.handler_); |
| ASIO_HANDLER_INVOCATION_END; |
| } |
| } |
| } |
| |
| private: |
| socket_ops::weak_cancel_token_type cancel_token_; |
| query_type query_; |
| io_context_impl& io_context_impl_; |
| Handler handler_; |
| asio::detail::addrinfo_type* addrinfo_; |
| }; |
| |
| } // namespace detail |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #endif // ASIO_DETAIL_RESOLVE_QUERY_OP_HPP |