/Src/Dependencies/Boost/boost/asio/detail/resolver_service_base.hpp

  1//
  2// detail/resolver_service_base.hpp
  3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  4//
  5// Copyright (c) 2003-2011 Christopher M. Kohlhoff (chris at kohlhoff dot com)
  6//
  7// Distributed under the Boost Software License, Version 1.0. (See accompanying
  8// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  9//
 10
 11#ifndef BOOST_ASIO_DETAIL_RESOLVER_SERVICE_BASE_HPP
 12#define BOOST_ASIO_DETAIL_RESOLVER_SERVICE_BASE_HPP
 13
 14#if defined(_MSC_VER) && (_MSC_VER >= 1200)
 15# pragma once
 16#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 17
 18#include <boost/asio/detail/config.hpp>
 19#include <boost/asio/error.hpp>
 20#include <boost/asio/io_service.hpp>
 21#include <boost/asio/detail/mutex.hpp>
 22#include <boost/asio/detail/noncopyable.hpp>
 23#include <boost/asio/detail/operation.hpp>
 24#include <boost/asio/detail/socket_ops.hpp>
 25#include <boost/asio/detail/socket_types.hpp>
 26#include <boost/asio/detail/scoped_ptr.hpp>
 27#include <boost/asio/detail/thread.hpp>
 28
 29#include <boost/asio/detail/push_options.hpp>
 30
 31namespace boost {
 32namespace asio {
 33namespace detail {
 34
 35class resolver_service_base
 36{
 37public:
 38  // The implementation type of the resolver. A cancellation token is used to
 39  // indicate to the background thread that the operation has been cancelled.
 40  typedef socket_ops::shared_cancel_token_type implementation_type;
 41
 42  // Constructor.
 43  BOOST_ASIO_DECL resolver_service_base(boost::asio::io_service& io_service);
 44
 45  // Destructor.
 46  BOOST_ASIO_DECL ~resolver_service_base();
 47
 48  // Destroy all user-defined handler objects owned by the service.
 49  BOOST_ASIO_DECL void shutdown_service();
 50
 51  // Perform any fork-related housekeeping.
 52  BOOST_ASIO_DECL void fork_service(
 53      boost::asio::io_service::fork_event fork_ev);
 54
 55  // Construct a new resolver implementation.
 56  BOOST_ASIO_DECL void construct(implementation_type& impl);
 57
 58  // Destroy a resolver implementation.
 59  BOOST_ASIO_DECL void destroy(implementation_type&);
 60
 61  // Cancel pending asynchronous operations.
 62  BOOST_ASIO_DECL void cancel(implementation_type& impl);
 63
 64protected:
 65  // Helper function to start an asynchronous resolve operation.
 66  BOOST_ASIO_DECL void start_resolve_op(operation* op);
 67
 68  // Helper class to perform exception-safe cleanup of addrinfo objects.
 69  class auto_addrinfo
 70    : private boost::asio::detail::noncopyable
 71  {
 72  public:
 73    explicit auto_addrinfo(boost::asio::detail::addrinfo_type* ai)
 74      : ai_(ai)
 75    {
 76    }
 77
 78    ~auto_addrinfo()
 79    {
 80      if (ai_)
 81        socket_ops::freeaddrinfo(ai_);
 82    }
 83
 84    operator boost::asio::detail::addrinfo_type*()
 85    {
 86      return ai_;
 87    }
 88
 89  private:
 90    boost::asio::detail::addrinfo_type* ai_;
 91  };
 92
 93  // Helper class to run the work io_service in a thread.
 94  class work_io_service_runner;
 95
 96  // Start the work thread if it's not already running.
 97  BOOST_ASIO_DECL void start_work_thread();
 98
 99  // The io_service implementation used to post completions.
100  io_service_impl& io_service_impl_;
101
102private:
103  // Mutex to protect access to internal data.
104  boost::asio::detail::mutex mutex_;
105
106  // Private io_service used for performing asynchronous host resolution.
107  boost::asio::detail::scoped_ptr<boost::asio::io_service> work_io_service_;
108
109  // The work io_service implementation used to post completions.
110  io_service_impl& work_io_service_impl_;
111
112  // Work for the private io_service to perform.
113  boost::asio::detail::scoped_ptr<boost::asio::io_service::work> work_;
114
115  // Thread used for running the work io_service's run loop.
116  boost::asio::detail::scoped_ptr<boost::asio::detail::thread> work_thread_;
117};
118
119} // namespace detail
120} // namespace asio
121} // namespace boost
122
123#include <boost/asio/detail/pop_options.hpp>
124
125#if defined(BOOST_ASIO_HEADER_ONLY)
126# include <boost/asio/detail/impl/resolver_service_base.ipp>
127#endif // defined(BOOST_ASIO_HEADER_ONLY)
128
129#endif // BOOST_ASIO_DETAIL_RESOLVER_SERVICE_BASE_HPP