text: //
  // detail/win_iocp_socket_accept_op.hpp
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  //
  // Copyright (c) 2003-2016 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 ASIO_DETAIL_WIN_IOCP_SOCKET_ACCEPT_OP_HPP
  #define ASIO_DETAIL_WIN_IOCP_SOCKET_ACCEPT_OP_HPP
  
  #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  # pragma once
  #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  
  #include "asio/detail/config.hpp"
  
  #if defined(ASIO_HAS_IOCP)
  
  #include "asio/detail/bind_handler.hpp"
  #include "asio/detail/buffer_sequence_adapter.hpp"
  #include "asio/detail/fenced_block.hpp"
  #include "asio/detail/handler_alloc_helpers.hpp"
  #include "asio/detail/handler_invoke_helpers.hpp"
  #include "asio/detail/memory.hpp"
  #include "asio/detail/operation.hpp"
  #include "asio/detail/socket_ops.hpp"
  #include "asio/detail/win_iocp_socket_service_base.hpp"
  #include "asio/error.hpp"
  
  #include "asio/detail/push_options.hpp"
  
  namespace asio {
  namespace detail {
  
  template <typename Socket, typename Protocol, typename Handler>
  class win_iocp_socket_accept_op : public operation
  {
  public:
    ASIO_DEFINE_HANDLER_PTR(win_iocp_socket_accept_op);
  
    win_iocp_socket_accept_op(win_iocp_socket_service_base& socket_service,
        socket_type socket, Socket& peer, const Protocol& protocol,
        typename Protocol::endpoint* peer_endpoint,
        bool enable_connection_aborted, Handler& handler)
      : operation(&win_iocp_socket_accept_op::do_complete),
        socket_service_(socket_service),
        socket_(socket),
        peer_(peer),
        protocol_(protocol),
        peer_endpoint_(peer_endpoint),
        enable_connection_aborted_(enable_connection_aborted),
        handler_(ASIO_MOVE_CAST(Handler)(handler))
    {
      handler_work<Handler>::start(handler_);
    }
  
    socket_holder& new_socket()
    {
      return new_socket_;
    }
  
    void* output_buffer()
    {
      return output_buffer_;
    }
  
    DWORD address_length()
    {
      return sizeof(sockaddr_storage_type) + 16;
    }
  
    static void do_complete(void* owner, operation* base,
        const asio::error_code& result_ec,
        std::size_t /*bytes_transferred*/)
    {
      asio::error_code ec(result_ec);
  
      // Take ownership of the operation object.
      win_iocp_socket_accept_op* o(static_cast<win_iocp_socket_accept_op*>(base));
      ptr p = { asio::detail::addressof(o->handler_), o, o };
      handler_work<Handler> w(o->handler_);
  
      if (owner)
      {
        typename Protocol::endpoint peer_endpoint;
        std::size_t addr_len = peer_endpoint.capacity();
        socket_ops::complete_iocp_accept(o->socket_,
            o->output_buffer(), o->address_length(),
            peer_endpoint.data(), &addr_len,
            o->new_socket_.get(), ec);
  
        // Restart the accept operation if we got the connection_aborted error
        // and the enable_connection_aborted socket option is not set.
        if (ec == asio::error::connection_aborted
            && !o->enable_connection_aborted_)
        {
          o->reset();
          o->socket_service_.restart_accept_op(o->socket_,
              o->new_socket_, o->protocol_.family(),
              o->protocol_.type(), o->protocol_.protocol(),
              o->output_buffer(), o->address_length(), o);
          p.v = p.p = 0;
          return;
        }
  
        // If the socket was successfully accepted, transfer ownership of the
        // socket to the peer object.
        if (!ec)
        {
          o->peer_.assign(o->protocol_,
              typename Socket::native_handle_type(
                o->new_socket_.get(), peer_endpoint), ec);
          if (!ec)
            o->new_socket_.release();
        }
  
        // Pass endpoint back to caller.
        if (o->peer_endpoint_)
          *o->peer_endpoint_ = peer_endpoint;
      }
  
      ASIO_HANDLER_COMPLETION((*o));
  
      // Make a copy of the handler so that the memory can be deallocated before
      // the upcall is made. Even if we're not about to make an upcall, a
      // sub-object of the handler may be the true owner of the memory associated
      // with the handler. Consequently, a local copy of the handler is required
      // to ensure that any owning sub-object remains valid until after we have
      // deallocated the memory here.
      detail::binder1<Handler, asio::error_code>
        handler(o->handler_, ec);
      p.h = asio::detail::addressof(handler.handler_);
      p.reset();
  
      // Make the upcall if required.
      if (owner)
      {
        fenced_block b(fenced_block::half);
        ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_));
        w.complete(handler, handler.handler_);
        ASIO_HANDLER_INVOCATION_END;
      }
    }
  
  private:
    win_iocp_socket_service_base& socket_service_;
    socket_type socket_;
    socket_holder new_socket_;
    Socket& peer_;
    Protocol protocol_;
    typename Protocol::endpoint* peer_endpoint_;
    unsigned char output_buffer_[(sizeof(sockaddr_storage_type) + 16) * 2];
    bool enable_connection_aborted_;
    Handler handler_;
  };
  
  #if defined(ASIO_HAS_MOVE)
  
  template <typename Protocol, typename Handler>
  class win_iocp_socket_move_accept_op : public operation
  {
  public:
    ASIO_DEFINE_HANDLER_PTR(win_iocp_socket_move_accept_op);
  
    win_iocp_socket_move_accept_op(
        win_iocp_socket_service_base& socket_service, socket_type socket,
        const Protocol& protocol, asio::io_context& peer_io_context,
        typename Protocol::endpoint* peer_endpoint,
        bool enable_connection_aborted, Handler& handler)
      : operation(&win_iocp_socket_move_accept_op::do_complete),
        socket_service_(socket_service),
        socket_(socket),
        peer_(peer_io_context),
        protocol_(protocol),
        peer_endpoint_(peer_endpoint),
        enable_connection_aborted_(enable_connection_aborted),
        handler_(ASIO_MOVE_CAST(Handler)(handler))
    {
      handler_work<Handler>::start(handler_);
    }
  
    socket_holder& new_socket()
    {
      return new_socket_;
    }
  
    void* output_buffer()
    {
      return output_buffer_;
    }
  
    DWORD address_length()
    {
      return sizeof(sockaddr_storage_type) + 16;
    }
  
    static void do_complete(void* owner, operation* base,
        const asio::error_code& result_ec,
        std::size_t /*bytes_transferred*/)
    {
      asio::error_code ec(result_ec);
  
      // Take ownership of the operation object.
      win_iocp_socket_move_accept_op* o(
          static_cast<win_iocp_socket_move_accept_op*>(base));
      ptr p = { asio::detail::addressof(o->handler_), o, o };
      handler_work<Handler> w(o->handler_);
  
      if (owner)
      {
        typename Protocol::endpoint peer_endpoint;
        std::size_t addr_len = peer_endpoint.capacity();
        socket_ops::complete_iocp_accept(o->socket_,
            o->output_buffer(), o->address_length(),
            peer_endpoint.data(), &addr_len,
            o->new_socket_.get(), ec);
  
        // Restart the accept operation if we got the connection_aborted error
        // and the enable_connection_aborted socket option is not set.
        if (ec == asio::error::connection_aborted
            && !o->enable_connection_aborted_)
        {
          o->reset();
          o->socket_service_.restart_accept_op(o->socket_,
              o->new_socket_, o->protocol_.family(),
              o->protocol_.type(), o->protocol_.protocol(),
              o->output_buffer(), o->address_length(), o);
          p.v = p.p = 0;
          return;
        }
  
        // If the socket was successfully accepted, transfer ownership of the
        // socket to the peer object.
        if (!ec)
        {
          o->peer_.assign(o->protocol_,
              typename Protocol::socket::native_handle_type(
                o->new_socket_.get(), peer_endpoint), ec);
          if (!ec)
            o->new_socket_.release();
        }
  
        // Pass endpoint back to caller.
        if (o->peer_endpoint_)
          *o->peer_endpoint_ = peer_endpoint;
      }
  
      ASIO_HANDLER_COMPLETION((*o));
  
      // Make a copy of the handler so that the memory can be deallocated before
      // the upcall is made. Even if we're not about to make an upcall, a
      // sub-object of the handler may be the true owner of the memory associated
      // with the handler. Consequently, a local copy of the handler is required
      // to ensure that any owning sub-object remains valid until after we have
      // deallocated the memory here.
      detail::move_binder2<Handler,
        asio::error_code, typename Protocol::socket>
          handler(0, ASIO_MOVE_CAST(Handler)(o->handler_), ec,
            ASIO_MOVE_CAST(typename Protocol::socket)(o->peer_));
      p.h = asio::detail::addressof(handler.handler_);
      p.reset();
  
      // Make the upcall if required.
      if (owner)
      {
        fenced_block b(fenced_block::half);
        ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, "..."));
        w.complete(handler, handler.handler_);
        ASIO_HANDLER_INVOCATION_END;
      }
    }
  
  private:
    win_iocp_socket_service_base& socket_service_;
    socket_type socket_;
    socket_holder new_socket_;
    typename Protocol::socket peer_;
    Protocol protocol_;
    typename Protocol::endpoint* peer_endpoint_;
    unsigned char output_buffer_[(sizeof(sockaddr_storage_type) + 16) * 2];
    bool enable_connection_aborted_;
    Handler handler_;
  };
  
  #endif // defined(ASIO_HAS_MOVE)
  
  } // namespace detail
  } // namespace asio
  
  #include "asio/detail/pop_options.hpp"
  
  #endif // defined(ASIO_HAS_IOCP)
  
  #endif // ASIO_DETAIL_WIN_IOCP_SOCKET_ACCEPT_OP_HPP
  