ext-boost/boost/asio/detail/resolver_service_base.hpp

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2019-08-24 13:39:04 +00:00
//
// detail/resolver_service_base.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_SERVICE_BASE_HPP
#define BOOST_ASIO_DETAIL_RESOLVER_SERVICE_BASE_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/execution_context.hpp>
#include <boost/asio/detail/mutex.hpp>
#include <boost/asio/detail/noncopyable.hpp>
#include <boost/asio/detail/resolve_op.hpp>
#include <boost/asio/detail/socket_ops.hpp>
#include <boost/asio/detail/socket_types.hpp>
#include <boost/asio/detail/scoped_ptr.hpp>
#include <boost/asio/detail/thread.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 {
class resolver_service_base
{
public:
// The implementation type of the resolver. A cancellation token is used to
// indicate to the background thread that the operation has been cancelled.
typedef socket_ops::shared_cancel_token_type implementation_type;
// Constructor.
BOOST_ASIO_DECL resolver_service_base(execution_context& context);
// Destructor.
BOOST_ASIO_DECL ~resolver_service_base();
// Destroy all user-defined handler objects owned by the service.
BOOST_ASIO_DECL void base_shutdown();
// Perform any fork-related housekeeping.
BOOST_ASIO_DECL void base_notify_fork(
execution_context::fork_event fork_ev);
// Construct a new resolver implementation.
BOOST_ASIO_DECL void construct(implementation_type& impl);
// Destroy a resolver implementation.
BOOST_ASIO_DECL void destroy(implementation_type&);
// Move-construct a new resolver implementation.
BOOST_ASIO_DECL void move_construct(implementation_type& impl,
implementation_type& other_impl);
// Move-assign from another resolver implementation.
BOOST_ASIO_DECL void move_assign(implementation_type& impl,
resolver_service_base& other_service,
implementation_type& other_impl);
// Cancel pending asynchronous operations.
BOOST_ASIO_DECL void cancel(implementation_type& impl);
protected:
// Helper function to start an asynchronous resolve operation.
BOOST_ASIO_DECL void start_resolve_op(resolve_op* op);
#if !defined(BOOST_ASIO_WINDOWS_RUNTIME)
// Helper class to perform exception-safe cleanup of addrinfo objects.
class auto_addrinfo
: private boost::asio::detail::noncopyable
{
public:
explicit auto_addrinfo(boost::asio::detail::addrinfo_type* ai)
: ai_(ai)
{
}
~auto_addrinfo()
{
if (ai_)
socket_ops::freeaddrinfo(ai_);
}
operator boost::asio::detail::addrinfo_type*()
{
return ai_;
}
private:
boost::asio::detail::addrinfo_type* ai_;
};
#endif // !defined(BOOST_ASIO_WINDOWS_RUNTIME)
// Helper class to run the work scheduler in a thread.
class work_scheduler_runner;
// Start the work scheduler if it's not already running.
BOOST_ASIO_DECL void start_work_thread();
// The scheduler implementation used to post completions.
#if defined(BOOST_ASIO_HAS_IOCP)
typedef class win_iocp_io_context scheduler_impl;
#else
typedef class scheduler scheduler_impl;
#endif
scheduler_impl& scheduler_;
private:
// Mutex to protect access to internal data.
boost::asio::detail::mutex mutex_;
// Private scheduler used for performing asynchronous host resolution.
boost::asio::detail::scoped_ptr<scheduler_impl> work_scheduler_;
// Thread used for running the work io_context's run loop.
boost::asio::detail::scoped_ptr<boost::asio::detail::thread> work_thread_;
};
} // namespace detail
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#if defined(BOOST_ASIO_HEADER_ONLY)
# include <boost/asio/detail/impl/resolver_service_base.ipp>
#endif // defined(BOOST_ASIO_HEADER_ONLY)
#endif // BOOST_ASIO_DETAIL_RESOLVER_SERVICE_BASE_HPP