text: //
  // detail/reactive_socket_service.hpp
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  //
  // Copyright (c) 2003-2010 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_REACTIVE_SOCKET_SERVICE_HPP
  #define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_HPP
  
  #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  # pragma once
  #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  
  #include <boost/asio/detail/config.hpp>
  
  #if !defined(BOOST_ASIO_HAS_IOCP)
  
  #include <boost/utility/addressof.hpp>
  #include <boost/asio/buffer.hpp>
  #include <boost/asio/error.hpp>
  #include <boost/asio/io_service.hpp>
  #include <boost/asio/socket_base.hpp>
  #include <boost/asio/detail/buffer_sequence_adapter.hpp>
  #include <boost/asio/detail/noncopyable.hpp>
  #include <boost/asio/detail/reactive_null_buffers_op.hpp>
  #include <boost/asio/detail/reactive_socket_accept_op.hpp>
  #include <boost/asio/detail/reactive_socket_connect_op.hpp>
  #include <boost/asio/detail/reactive_socket_recvfrom_op.hpp>
  #include <boost/asio/detail/reactive_socket_sendto_op.hpp>
  #include <boost/asio/detail/reactive_socket_service_base.hpp>
  #include <boost/asio/detail/reactor.hpp>
  #include <boost/asio/detail/reactor_op.hpp>
  #include <boost/asio/detail/socket_holder.hpp>
  #include <boost/asio/detail/socket_ops.hpp>
  #include <boost/asio/detail/socket_types.hpp>
  
  #include <boost/asio/detail/push_options.hpp>
  
  namespace boost {
  namespace asio {
  namespace detail {
  
  template <typename Protocol>
  class reactive_socket_service :
    public reactive_socket_service_base
  {
  public:
    // The protocol type.
    typedef Protocol protocol_type;
  
    // The endpoint type.
    typedef typename Protocol::endpoint endpoint_type;
  
    // The native type of a socket.
    typedef socket_type native_type;
  
    // The implementation type of the socket.
    struct implementation_type :
      reactive_socket_service_base::base_implementation_type
    {
      // Default constructor.
      implementation_type()
        : protocol_(endpoint_type().protocol())
      {
      }
  
      // The protocol associated with the socket.
      protocol_type protocol_;
    };
  
    // Constructor.
    reactive_socket_service(boost::asio::io_service& io_service)
      : reactive_socket_service_base(io_service)
    {
    }
  
    // Open a new socket implementation.
    boost::system::error_code open(implementation_type& impl,
        const protocol_type& protocol, boost::system::error_code& ec)
    {
      if (!do_open(impl, protocol.family(),
            protocol.type(), protocol.protocol(), ec))
        impl.protocol_ = protocol;
      return ec;
    }
  
    // Assign a native socket to a socket implementation.
    boost::system::error_code assign(implementation_type& impl,
        const protocol_type& protocol, const native_type& native_socket,
        boost::system::error_code& ec)
    {
      if (!do_assign(impl, protocol.type(), native_socket, ec))
        impl.protocol_ = protocol;
      return ec;
    }
  
    // Get the native socket representation.
    native_type native(implementation_type& impl)
    {
      return impl.socket_;
    }
  
    // Bind the socket to the specified local endpoint.
    boost::system::error_code bind(implementation_type& impl,
        const endpoint_type& endpoint, boost::system::error_code& ec)
    {
      socket_ops::bind(impl.socket_, endpoint.data(), endpoint.size(), ec);
      return ec;
    }
  
    // Set a socket option.
    template <typename Option>
    boost::system::error_code set_option(implementation_type& impl,
        const Option& option, boost::system::error_code& ec)
    {
      socket_ops::setsockopt(impl.socket_, impl.state_,
          option.level(impl.protocol_), option.name(impl.protocol_),
          option.data(impl.protocol_), option.size(impl.protocol_), ec);
      return ec;
    }
  
    // Set a socket option.
    template <typename Option>
    boost::system::error_code get_option(const implementation_type& impl,
        Option& option, boost::system::error_code& ec) const
    {
      std::size_t size = option.size(impl.protocol_);
      socket_ops::getsockopt(impl.socket_, impl.state_,
          option.level(impl.protocol_), option.name(impl.protocol_),
          option.data(impl.protocol_), &size, ec);
      if (!ec)
        option.resize(impl.protocol_, size);
      return ec;
    }
  
    // Get the local endpoint.
    endpoint_type local_endpoint(const implementation_type& impl,
        boost::system::error_code& ec) const
    {
      endpoint_type endpoint;
      std::size_t addr_len = endpoint.capacity();
      if (socket_ops::getsockname(impl.socket_, endpoint.data(), &addr_len, ec))
        return endpoint_type();
      endpoint.resize(addr_len);
      return endpoint;
    }
  
    // Get the remote endpoint.
    endpoint_type remote_endpoint(const implementation_type& impl,
        boost::system::error_code& ec) const
    {
      endpoint_type endpoint;
      std::size_t addr_len = endpoint.capacity();
      if (socket_ops::getpeername(impl.socket_,
            endpoint.data(), &addr_len, false, ec))
        return endpoint_type();
      endpoint.resize(addr_len);
      return endpoint;
    }
  
    // Send a datagram to the specified endpoint. Returns the number of bytes
    // sent.
    template <typename ConstBufferSequence>
    size_t send_to(implementation_type& impl, const ConstBufferSequence& buffers,
        const endpoint_type& destination, socket_base::message_flags flags,
        boost::system::error_code& ec)
    {
      buffer_sequence_adapter<boost::asio::const_buffer,
          ConstBufferSequence> bufs(buffers);
  
      return socket_ops::sync_sendto(impl.socket_, impl.state_,
          bufs.buffers(), bufs.count(), flags,
          destination.data(), destination.size(), ec);
    }
  
    // Wait until data can be sent without blocking.
    size_t send_to(implementation_type& impl, const null_buffers&,
        const endpoint_type&, socket_base::message_flags,
        boost::system::error_code& ec)
    {
      // Wait for socket to become ready.
      socket_ops::poll_write(impl.socket_, ec);
  
      return 0;
    }
  
    // Start an asynchronous send. The data being sent must be valid for the
    // lifetime of the asynchronous operation.
    template <typename ConstBufferSequence, typename Handler>
    void async_send_to(implementation_type& impl,
        const ConstBufferSequence& buffers,
        const endpoint_type& destination, socket_base::message_flags flags,
        Handler handler)
    {
      // Allocate and construct an operation to wrap the handler.
      typedef reactive_socket_sendto_op<ConstBufferSequence,
          endpoint_type, Handler> op;
      typename op::ptr p = { boost::addressof(handler),
        boost_asio_handler_alloc_helpers::allocate(
          sizeof(op), handler), 0 };
      p.p = new (p.v) op(impl.socket_, buffers, destination, flags, handler);
  
      start_op(impl, reactor::write_op, p.p, true, false);
      p.v = p.p = 0;
    }
  
    // Start an asynchronous wait until data can be sent without blocking.
    template <typename Handler>
    void async_send_to(implementation_type& impl, const null_buffers&,
        const endpoint_type&, socket_base::message_flags, Handler handler)
    {
      // Allocate and construct an operation to wrap the handler.
      typedef reactive_null_buffers_op<Handler> op;
      typename op::ptr p = { boost::addressof(handler),
        boost_asio_handler_alloc_helpers::allocate(
          sizeof(op), handler), 0 };
      p.p = new (p.v) op(handler);
  
      start_op(impl, reactor::write_op, p.p, false, false);
      p.v = p.p = 0;
    }
  
    // Receive a datagram with the endpoint of the sender. Returns the number of
    // bytes received.
    template <typename MutableBufferSequence>
    size_t receive_from(implementation_type& impl,
        const MutableBufferSequence& buffers,
        endpoint_type& sender_endpoint, socket_base::message_flags flags,
        boost::system::error_code& ec)
    {
      buffer_sequence_adapter<boost::asio::mutable_buffer,
          MutableBufferSequence> bufs(buffers);
  
      std::size_t addr_len = sender_endpoint.capacity();
      std::size_t bytes_recvd = socket_ops::sync_recvfrom(
          impl.socket_, impl.state_, bufs.buffers(), bufs.count(),
          flags, sender_endpoint.data(), &addr_len, ec);
  
      if (!ec)
        sender_endpoint.resize(addr_len);
  
      return bytes_recvd;
    }
  
    // Wait until data can be received without blocking.
    size_t receive_from(implementation_type& impl, const null_buffers&,
        endpoint_type& sender_endpoint, socket_base::message_flags,
        boost::system::error_code& ec)
    {
      // Wait for socket to become ready.
      socket_ops::poll_read(impl.socket_, ec);
  
      // Reset endpoint since it can be given no sensible value at this time.
      sender_endpoint = endpoint_type();
  
      return 0;
    }
  
    // Start an asynchronous receive. The buffer for the data being received and
    // the sender_endpoint object must both be valid for the lifetime of the
    // asynchronous operation.
    template <typename MutableBufferSequence, typename Handler>
    void async_receive_from(implementation_type& impl,
        const MutableBufferSequence& buffers, endpoint_type& sender_endpoint,
        socket_base::message_flags flags, Handler handler)
    {
      // Allocate and construct an operation to wrap the handler.
      typedef reactive_socket_recvfrom_op<MutableBufferSequence,
          endpoint_type, Handler> op;
      typename op::ptr p = { boost::addressof(handler),
        boost_asio_handler_alloc_helpers::allocate(
          sizeof(op), handler), 0 };
      int protocol_type = impl.protocol_.type();
      p.p = new (p.v) op(impl.socket_, protocol_type,
          buffers, sender_endpoint, flags, handler);
  
      start_op(impl,
          (flags & socket_base::message_out_of_band)
            ? reactor::except_op : reactor::read_op,
          p.p, true, false);
      p.v = p.p = 0;
    }
  
    // Wait until data can be received without blocking.
    template <typename Handler>
    void async_receive_from(implementation_type& impl,
        const null_buffers&, endpoint_type& sender_endpoint,
        socket_base::message_flags flags, Handler handler)
    {
      // Allocate and construct an operation to wrap the handler.
      typedef reactive_null_buffers_op<Handler> op;
      typename op::ptr p = { boost::addressof(handler),
        boost_asio_handler_alloc_helpers::allocate(
          sizeof(op), handler), 0 };
      p.p = new (p.v) op(handler);
  
      // Reset endpoint since it can be given no sensible value at this time.
      sender_endpoint = endpoint_type();
  
      start_op(impl,
          (flags & socket_base::message_out_of_band)
            ? reactor::except_op : reactor::read_op,
          p.p, false, false);
      p.v = p.p = 0;
    }
  
    // Accept a new connection.
    template <typename Socket>
    boost::system::error_code accept(implementation_type& impl,
        Socket& peer, endpoint_type* peer_endpoint, boost::system::error_code& ec)
    {
      // We cannot accept a socket that is already open.
      if (peer.is_open())
      {
        ec = boost::asio::error::already_open;
        return ec;
      }
  
      std::size_t addr_len = peer_endpoint ? peer_endpoint->capacity() : 0;
      socket_holder new_socket(socket_ops::sync_accept(impl.socket_,
            impl.state_, peer_endpoint ? peer_endpoint->data() : 0,
            peer_endpoint ? &addr_len : 0, ec));
  
      // On success, assign new connection to peer socket object.
      if (new_socket.get() >= 0)
      {
        if (peer_endpoint)
          peer_endpoint->resize(addr_len);
        if (!peer.assign(impl.protocol_, new_socket.get(), ec))
          new_socket.release();
      }
  
      return ec;
    }
  
    // Start an asynchronous accept. The peer and peer_endpoint objects
    // must be valid until the accept's handler is invoked.
    template <typename Socket, typename Handler>
    void async_accept(implementation_type& impl, Socket& peer,
        endpoint_type* peer_endpoint, Handler handler)
    {
      // Allocate and construct an operation to wrap the handler.
      typedef reactive_socket_accept_op<Socket, Protocol, Handler> op;
      typename op::ptr p = { boost::addressof(handler),
        boost_asio_handler_alloc_helpers::allocate(
          sizeof(op), handler), 0 };
      p.p = new (p.v) op(impl.socket_, impl.state_, peer,
          impl.protocol_, peer_endpoint, handler);
  
      start_accept_op(impl, p.p, peer.is_open());
      p.v = p.p = 0;
    }
  
    // Connect the socket to the specified endpoint.
    boost::system::error_code connect(implementation_type& impl,
        const endpoint_type& peer_endpoint, boost::system::error_code& ec)
    {
      socket_ops::sync_connect(impl.socket_,
          peer_endpoint.data(), peer_endpoint.size(), ec);
      return ec;
    }
  
    // Start an asynchronous connect.
    template <typename Handler>
    void async_connect(implementation_type& impl,
        const endpoint_type& peer_endpoint, Handler handler)
    {
      // Allocate and construct an operation to wrap the handler.
      typedef reactive_socket_connect_op<Handler> op;
      typename op::ptr p = { boost::addressof(handler),
        boost_asio_handler_alloc_helpers::allocate(
          sizeof(op), handler), 0 };
      p.p = new (p.v) op(impl.socket_, handler);
  
      start_connect_op(impl, p.p, peer_endpoint.data(), peer_endpoint.size());
      p.v = p.p = 0;
    }
  };
  
  } // namespace detail
  } // namespace asio
  } // namespace boost
  
  #include <boost/asio/detail/pop_options.hpp>
  
  #endif // !defined(BOOST_ASIO_HAS_IOCP)
  
  #endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_HPP
  