|
- //
- // detail/resolve_endpoint_op.hpp
- // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2019 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_RESOLVER_ENDPOINT_OP_HPP
- #define ASIO_DETAIL_RESOLVER_ENDPOINT_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/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"
-
- #if defined(ASIO_HAS_IOCP)
- # include "asio/detail/win_iocp_io_context.hpp"
- #else // defined(ASIO_HAS_IOCP)
- # include "asio/detail/scheduler.hpp"
- #endif // defined(ASIO_HAS_IOCP)
-
- #include "asio/detail/push_options.hpp"
-
- namespace asio {
- namespace detail {
-
- template <typename Protocol, typename Handler, typename IoExecutor>
- class resolve_endpoint_op : public resolve_op
- {
- public:
- ASIO_DEFINE_HANDLER_PTR(resolve_endpoint_op);
-
- typedef typename Protocol::endpoint endpoint_type;
- typedef asio::ip::basic_resolver_results<Protocol> results_type;
-
- #if defined(ASIO_HAS_IOCP)
- typedef class win_iocp_io_context scheduler_impl;
- #else
- typedef class scheduler scheduler_impl;
- #endif
-
- resolve_endpoint_op(socket_ops::weak_cancel_token_type cancel_token,
- const endpoint_type& endpoint, scheduler_impl& sched,
- Handler& handler, const IoExecutor& io_ex)
- : resolve_op(&resolve_endpoint_op::do_complete),
- cancel_token_(cancel_token),
- endpoint_(endpoint),
- scheduler_(sched),
- handler_(ASIO_MOVE_CAST(Handler)(handler)),
- io_executor_(io_ex)
- {
- handler_work<Handler, IoExecutor>::start(handler_, io_executor_);
- }
-
- 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_endpoint_op* o(static_cast<resolve_endpoint_op*>(base));
- ptr p = { asio::detail::addressof(o->handler_), o, o };
- handler_work<Handler, IoExecutor> w(o->handler_, o->io_executor_);
-
- if (owner && owner != &o->scheduler_)
- {
- // The operation is being run on the worker io_context. Time to perform
- // the resolver operation.
-
- // Perform the blocking endpoint resolution operation.
- char host_name[NI_MAXHOST];
- char service_name[NI_MAXSERV];
- socket_ops::background_getnameinfo(o->cancel_token_, o->endpoint_.data(),
- o->endpoint_.size(), host_name, NI_MAXHOST, service_name, NI_MAXSERV,
- o->endpoint_.protocol().type(), o->ec_);
- o->results_ = results_type::create(o->endpoint_, host_name, service_name);
-
- // Pass operation back to main io_context for completion.
- o->scheduler_.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_, o->results_);
- p.h = asio::detail::addressof(handler.handler_);
- 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_;
- endpoint_type endpoint_;
- scheduler_impl& scheduler_;
- Handler handler_;
- IoExecutor io_executor_;
- results_type results_;
- };
-
- } // namespace detail
- } // namespace asio
-
- #include "asio/detail/pop_options.hpp"
-
- #endif // ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP
|