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

   1 //
   2 // detail/resolver_service_base.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2017 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/executor_work_guard.hpp>
  21 #include <boost/asio/io_context.hpp>
  22 #include <boost/asio/detail/mutex.hpp>
  23 #include <boost/asio/detail/noncopyable.hpp>
  24 #include <boost/asio/detail/resolve_op.hpp>
  25 #include <boost/asio/detail/socket_ops.hpp>
  26 #include <boost/asio/detail/socket_types.hpp>
  27 #include <boost/asio/detail/scoped_ptr.hpp>
  28 #include <boost/asio/detail/thread.hpp>
  29
  30 #include <boost/asio/detail/push_options.hpp>
  31
  32 namespace boost {
  33 namespace asio {
  34 namespace detail {
  35
  36 class resolver_service_base
  37 {
  38 public:
  39   // The implementation type of the resolver. A cancellation token is used to
  40   // indicate to the background thread that the operation has been cancelled.
  41   typedef socket_ops::shared_cancel_token_type implementation_type;
  42
  43   // Constructor.
  44   BOOST_ASIO_DECL resolver_service_base(boost::asio::io_context& io_context);
  45
  46   // Destructor.
  47   BOOST_ASIO_DECL ~resolver_service_base();
  48
  49   // Destroy all user-defined handler objects owned by the service.
  50   BOOST_ASIO_DECL void base_shutdown();
  51
  52   // Perform any fork-related housekeeping.
  53   BOOST_ASIO_DECL void base_notify_fork(
  54       boost::asio::io_context::fork_event fork_ev);
  55
  56   // Construct a new resolver implementation.
  57   BOOST_ASIO_DECL void construct(implementation_type& impl);
  58
  59   // Destroy a resolver implementation.
  60   BOOST_ASIO_DECL void destroy(implementation_type&);
  61
  62   // Move-construct a new resolver implementation.
  63   BOOST_ASIO_DECL void move_construct(implementation_type& impl,
  64       implementation_type& other_impl);
  65
  66   // Move-assign from another resolver implementation.
  67   BOOST_ASIO_DECL void move_assign(implementation_type& impl,
  68       resolver_service_base& other_service,
  69       implementation_type& other_impl);
  70
  71   // Cancel pending asynchronous operations.
  72   BOOST_ASIO_DECL void cancel(implementation_type& impl);
  73
  74 protected:
  75   // Helper function to start an asynchronous resolve operation.
  76   BOOST_ASIO_DECL void start_resolve_op(resolve_op* op);
  77
  78 #if !defined(BOOST_ASIO_WINDOWS_RUNTIME)
  79   // Helper class to perform exception-safe cleanup of addrinfo objects.
  80   class auto_addrinfo
  81     : private boost::asio::detail::noncopyable
  82   {
  83   public:
  84     explicit auto_addrinfo(boost::asio::detail::addrinfo_type* ai)
  85       : ai_(ai)
  86     {
  87     }
  88
  89     ~auto_addrinfo()
  90     {
  91       if (ai_)
  92         socket_ops::freeaddrinfo(ai_);
  93     }
  94
  95     operator boost::asio::detail::addrinfo_type*()
  96     {
  97       return ai_;
  98     }
  99
 100   private:
 101     boost::asio::detail::addrinfo_type* ai_;
 102   };
 103 #endif // !defined(BOOST_ASIO_WINDOWS_RUNTIME)
 104
 105   // Helper class to run the work io_context in a thread.
 106   class work_io_context_runner;
 107
 108   // Start the work thread if it's not already running.
 109   BOOST_ASIO_DECL void start_work_thread();
 110
 111   // The io_context implementation used to post completions.
 112   io_context_impl& io_context_impl_;
 113
 114 private:
 115   // Mutex to protect access to internal data.
 116   boost::asio::detail::mutex mutex_;
 117
 118   // Private io_context used for performing asynchronous host resolution.
 119   boost::asio::detail::scoped_ptr<boost::asio::io_context> work_io_context_;
 120
 121   // The work io_context implementation used to post completions.
 122   io_context_impl& work_io_context_impl_;
 123
 124   // Work for the private io_context to perform.
 125   boost::asio::executor_work_guard<
 126       boost::asio::io_context::executor_type> work_;
 127
 128   // Thread used for running the work io_context's run loop.
 129   boost::asio::detail::scoped_ptr<boost::asio::detail::thread> work_thread_;
 130 };
 131
 132 } // namespace detail
 133 } // namespace asio
 134 } // namespace boost
 135
 136 #include <boost/asio/detail/pop_options.hpp>
 137
 138 #if defined(BOOST_ASIO_HEADER_ONLY)
 139 # include <boost/asio/detail/impl/resolver_service_base.ipp>
 140 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 141
 142 #endif // BOOST_ASIO_DETAIL_RESOLVER_SERVICE_BASE_HPP