ext-boost/boost/asio/detail/resolve_endpoint_op.hpp
2019-08-24 15:39:04 +02:00

139 lines
4.7 KiB
C++

//
// 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 BOOST_ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP
#define BOOST_ASIO_DETAIL_RESOLVER_ENDPOINT_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/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>
#if defined(BOOST_ASIO_HAS_IOCP)
# include <boost/asio/detail/win_iocp_io_context.hpp>
#else // defined(BOOST_ASIO_HAS_IOCP)
# include <boost/asio/detail/scheduler.hpp>
#endif // defined(BOOST_ASIO_HAS_IOCP)
#include <boost/asio/detail/push_options.hpp>
namespace boost {
namespace asio {
namespace detail {
template <typename Protocol, typename Handler, typename IoExecutor>
class resolve_endpoint_op : public resolve_op
{
public:
BOOST_ASIO_DEFINE_HANDLER_PTR(resolve_endpoint_op);
typedef typename Protocol::endpoint endpoint_type;
typedef boost::asio::ip::basic_resolver_results<Protocol> results_type;
#if defined(BOOST_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_(BOOST_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 boost::system::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 = { boost::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.
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_, o->results_);
p.h = boost::asio::detail::addressof(handler.handler_);
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_;
endpoint_type endpoint_;
scheduler_impl& scheduler_;
Handler handler_;
IoExecutor io_executor_;
results_type results_;
};
} // namespace detail
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#endif // BOOST_ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP