ceph/src/boost/boost/asio/detail/resolver_service_base.hpp

   1 //
   2 // detail/resolver_service_base.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2022 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/execution_context.hpp>
  21 #include <boost/asio/detail/mutex.hpp>
  22 #include <boost/asio/detail/noncopyable.hpp>
  23 #include <boost/asio/detail/resolve_op.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 #if defined(BOOST_ASIO_HAS_IOCP)
  30 # include <boost/asio/detail/win_iocp_io_context.hpp>
  31 #else // defined(BOOST_ASIO_HAS_IOCP)
  32 # include <boost/asio/detail/scheduler.hpp>
  33 #endif // defined(BOOST_ASIO_HAS_IOCP)
  34
  35 #include <boost/asio/detail/push_options.hpp>
  36
  37 namespace boost {
  38 namespace asio {
  39 namespace detail {
  40
  41 class resolver_service_base
  42 {
  43 public:
  44   // The implementation type of the resolver. A cancellation token is used to
  45   // indicate to the background thread that the operation has been cancelled.
  46   typedef socket_ops::shared_cancel_token_type implementation_type;
  47
  48   // Constructor.
  49   BOOST_ASIO_DECL resolver_service_base(execution_context& context);
  50
  51   // Destructor.
  52   BOOST_ASIO_DECL ~resolver_service_base();
  53
  54   // Destroy all user-defined handler objects owned by the service.
  55   BOOST_ASIO_DECL void base_shutdown();
  56
  57   // Perform any fork-related housekeeping.
  58   BOOST_ASIO_DECL void base_notify_fork(
  59       execution_context::fork_event fork_ev);
  60
  61   // Construct a new resolver implementation.
  62   BOOST_ASIO_DECL void construct(implementation_type& impl);
  63
  64   // Destroy a resolver implementation.
  65   BOOST_ASIO_DECL void destroy(implementation_type&);
  66
  67   // Move-construct a new resolver implementation.
  68   BOOST_ASIO_DECL void move_construct(implementation_type& impl,
  69       implementation_type& other_impl);
  70
  71   // Move-assign from another resolver implementation.
  72   BOOST_ASIO_DECL void move_assign(implementation_type& impl,
  73       resolver_service_base& other_service,
  74       implementation_type& other_impl);
  75
  76   // Move-construct a new timer implementation.
  77   void converting_move_construct(implementation_type& impl,
  78       resolver_service_base&, implementation_type& other_impl)
  79   {
  80     move_construct(impl, other_impl);
  81   }
  82
  83   // Move-assign from another timer implementation.
  84   void converting_move_assign(implementation_type& impl,
  85       resolver_service_base& other_service,
  86       implementation_type& other_impl)
  87   {
  88     move_assign(impl, other_service, other_impl);
  89   }
  90
  91   // Cancel pending asynchronous operations.
  92   BOOST_ASIO_DECL void cancel(implementation_type& impl);
  93
  94 protected:
  95   // Helper function to start an asynchronous resolve operation.
  96   BOOST_ASIO_DECL void start_resolve_op(resolve_op* op);
  97
  98 #if !defined(BOOST_ASIO_WINDOWS_RUNTIME)
  99   // Helper class to perform exception-safe cleanup of addrinfo objects.
 100   class auto_addrinfo
 101     : private boost::asio::detail::noncopyable
 102   {
 103   public:
 104     explicit auto_addrinfo(boost::asio::detail::addrinfo_type* ai)
 105       : ai_(ai)
 106     {
 107     }
 108
 109     ~auto_addrinfo()
 110     {
 111       if (ai_)
 112         socket_ops::freeaddrinfo(ai_);
 113     }
 114
 115     operator boost::asio::detail::addrinfo_type*()
 116     {
 117       return ai_;
 118     }
 119
 120   private:
 121     boost::asio::detail::addrinfo_type* ai_;
 122   };
 123 #endif // !defined(BOOST_ASIO_WINDOWS_RUNTIME)
 124
 125   // Helper class to run the work scheduler in a thread.
 126   class work_scheduler_runner;
 127
 128   // Start the work scheduler if it's not already running.
 129   BOOST_ASIO_DECL void start_work_thread();
 130
 131   // The scheduler implementation used to post completions.
 132 #if defined(BOOST_ASIO_HAS_IOCP)
 133   typedef class win_iocp_io_context scheduler_impl;
 134 #else
 135   typedef class scheduler scheduler_impl;
 136 #endif
 137   scheduler_impl& scheduler_;
 138
 139 private:
 140   // Mutex to protect access to internal data.
 141   boost::asio::detail::mutex mutex_;
 142
 143   // Private scheduler used for performing asynchronous host resolution.
 144   boost::asio::detail::scoped_ptr<scheduler_impl> work_scheduler_;
 145
 146   // Thread used for running the work io_context's run loop.
 147   boost::asio::detail::scoped_ptr<boost::asio::detail::thread> work_thread_;
 148 };
 149
 150 } // namespace detail
 151 } // namespace asio
 152 } // namespace boost
 153
 154 #include <boost/asio/detail/pop_options.hpp>
 155
 156 #if defined(BOOST_ASIO_HEADER_ONLY)
 157 # include <boost/asio/detail/impl/resolver_service_base.ipp>
 158 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 159
 160 #endif // BOOST_ASIO_DETAIL_RESOLVER_SERVICE_BASE_HPP