win_iocp_socket_service.hpp

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    DWORD last_error = ::WSAGetLastError();

    // Check if the operation completed immediately.
    if (result != 0 && last_error != WSA_IO_PENDING)
    {
      asio::io_service::work work(this->get_io_service());
      ptr.reset();
      asio::error_code ec(last_error,
          asio::error::get_system_category());
      iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
    }
    else
    {
      ptr.release();
    }
  }

  // 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,
      asio::error_code& ec)
  {
    if (!is_open(impl))
    {
      ec = asio::error::bad_descriptor;
      return 0;
    }

    // Copy buffers into WSABUF array.
    ::WSABUF bufs[max_buffers];
    typename ConstBufferSequence::const_iterator iter = buffers.begin();
    typename ConstBufferSequence::const_iterator end = buffers.end();
    DWORD i = 0;
    for (; iter != end && i < max_buffers; ++iter, ++i)
    {
      asio::const_buffer buffer(*iter);
      bufs[i].len = static_cast<u_long>(asio::buffer_size(buffer));
      bufs[i].buf = const_cast<char*>(
          asio::buffer_cast<const char*>(buffer));
    }

    // Send the data.
    DWORD bytes_transferred = 0;
    int result = ::WSASendTo(impl.socket_, bufs, i, &bytes_transferred,
        flags, destination.data(), destination.size(), 0, 0);
    if (result != 0)
    {
      DWORD last_error = ::WSAGetLastError();
      if (last_error == ERROR_PORT_UNREACHABLE)
        last_error = WSAECONNREFUSED;
      ec = asio::error_code(last_error,
          asio::error::get_system_category());
      return 0;
    }

    ec = asio::error_code();
    return bytes_transferred;
  }

  template <typename ConstBufferSequence, typename Handler>
  class send_to_operation
    : public operation
  {
  public:
    send_to_operation(asio::io_service& io_service,
        const ConstBufferSequence& buffers, Handler handler)
      : operation(
          &send_to_operation<ConstBufferSequence, Handler>::do_completion_impl,
          &send_to_operation<ConstBufferSequence, Handler>::destroy_impl),
        work_(io_service),
        buffers_(buffers),
        handler_(handler)
    {
    }

  private:
    static void do_completion_impl(operation* op,
        DWORD last_error, size_t bytes_transferred)
    {
      // Take ownership of the operation object.
      typedef send_to_operation<ConstBufferSequence, Handler> op_type;
      op_type* handler_op(static_cast<op_type*>(op));
      typedef handler_alloc_traits<Handler, op_type> alloc_traits;
      handler_ptr<alloc_traits> ptr(handler_op->handler_, handler_op);

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
      // Check whether buffers are still valid.
      typename ConstBufferSequence::const_iterator iter
        = handler_op->buffers_.begin();
      typename ConstBufferSequence::const_iterator end
        = handler_op->buffers_.end();
      while (iter != end)
      {
        asio::const_buffer buffer(*iter);
        asio::buffer_cast<const char*>(buffer);
        ++iter;
      }
#endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)

      // Map non-portable errors to their portable counterparts.
      asio::error_code ec(last_error,
          asio::error::get_system_category());
      if (ec.value() == ERROR_PORT_UNREACHABLE)
      {
        ec = asio::error::connection_refused;
      }

      // Make a copy of the handler so that the memory can be deallocated before
      // the upcall is made.
      Handler handler(handler_op->handler_);

      // Free the memory associated with the handler.
      ptr.reset();

      // Call the handler.
      asio_handler_invoke_helpers::invoke(
          detail::bind_handler(handler, ec, bytes_transferred), &handler);
    }

    static void destroy_impl(operation* op)
    {
      // Take ownership of the operation object.
      typedef send_to_operation<ConstBufferSequence, Handler> op_type;
      op_type* handler_op(static_cast<op_type*>(op));
      typedef handler_alloc_traits<Handler, op_type> alloc_traits;
      handler_ptr<alloc_traits> ptr(handler_op->handler_, handler_op);
    }

    asio::io_service::work work_;
    ConstBufferSequence buffers_;
    Handler handler_;
  };

  // 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)
  {
    if (!is_open(impl))
    {
      this->get_io_service().post(bind_handler(handler,
            asio::error::bad_descriptor, 0));
      return;
    }

    // Update the ID of the thread from which cancellation is safe.
    if (impl.safe_cancellation_thread_id_ == 0)
      impl.safe_cancellation_thread_id_ = ::GetCurrentThreadId();
    else if (impl.safe_cancellation_thread_id_ != ::GetCurrentThreadId())
      impl.safe_cancellation_thread_id_ = ~DWORD(0);

    // Allocate and construct an operation to wrap the handler.
    typedef send_to_operation<ConstBufferSequence, Handler> value_type;
    typedef handler_alloc_traits<Handler, value_type> alloc_traits;
    raw_handler_ptr<alloc_traits> raw_ptr(handler);
    handler_ptr<alloc_traits> ptr(raw_ptr,
        this->get_io_service(), buffers, handler);

    // Copy buffers into WSABUF array.
    ::WSABUF bufs[max_buffers];
    typename ConstBufferSequence::const_iterator iter = buffers.begin();
    typename ConstBufferSequence::const_iterator end = buffers.end();
    DWORD i = 0;
    for (; iter != end && i < max_buffers; ++iter, ++i)
    {
      asio::const_buffer buffer(*iter);
      bufs[i].len = static_cast<u_long>(asio::buffer_size(buffer));
      bufs[i].buf = const_cast<char*>(
          asio::buffer_cast<const char*>(buffer));
    }

    // Send the data.
    DWORD bytes_transferred = 0;
    int result = ::WSASendTo(impl.socket_, bufs, i, &bytes_transferred,
        flags, destination.data(), destination.size(), ptr.get(), 0);
    DWORD last_error = ::WSAGetLastError();

    // Check if the operation completed immediately.
    if (result != 0 && last_error != WSA_IO_PENDING)
    {
      asio::io_service::work work(this->get_io_service());
      ptr.reset();
      asio::error_code ec(last_error,
          asio::error::get_system_category());
      iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
    }
    else
    {
      ptr.release();
    }
  }

  // Receive some data from the peer. Returns the number of bytes received.
  template <typename MutableBufferSequence>
  size_t receive(implementation_type& impl,
      const MutableBufferSequence& buffers,
      socket_base::message_flags flags, asio::error_code& ec)
  {
    if (!is_open(impl))
    {
      ec = asio::error::bad_descriptor;
      return 0;
    }

    // Copy buffers into WSABUF array.
    ::WSABUF bufs[max_buffers];
    typename MutableBufferSequence::const_iterator iter = buffers.begin();
    typename MutableBufferSequence::const_iterator end = buffers.end();
    DWORD i = 0;
    size_t total_buffer_size = 0;
    for (; iter != end && i < max_buffers; ++iter, ++i)
    {
      asio::mutable_buffer buffer(*iter);
      bufs[i].len = static_cast<u_long>(asio::buffer_size(buffer));
      bufs[i].buf = asio::buffer_cast<char*>(buffer);
      total_buffer_size += asio::buffer_size(buffer);
    }

    // A request to receive 0 bytes on a stream socket is a no-op.
    if (impl.protocol_.type() == SOCK_STREAM && total_buffer_size == 0)
    {
      ec = asio::error_code();
      return 0;
    }

    // Receive some data.
    DWORD bytes_transferred = 0;
    DWORD recv_flags = flags;
    int result = ::WSARecv(impl.socket_, bufs, i,
        &bytes_transferred, &recv_flags, 0, 0);
    if (result != 0)
    {
      DWORD last_error = ::WSAGetLastError();
      if (last_error == ERROR_NETNAME_DELETED)
        last_error = WSAECONNRESET;
      else if (last_error == ERROR_PORT_UNREACHABLE)
        last_error = WSAECONNREFUSED;
      ec = asio::error_code(last_error,
          asio::error::get_system_category());
      return 0;
    }
    if (bytes_transferred == 0)
    {
      ec = asio::error::eof;
      return 0;
    }

    ec = asio::error_code();
    return bytes_transferred;
  }

  template <typename MutableBufferSequence, typename Handler>
  class receive_operation
    : public operation
  {
  public:
    receive_operation(asio::io_service& io_service,
        weak_cancel_token_type cancel_token,
        const MutableBufferSequence& buffers, Handler handler)
      : operation(
          &receive_operation<
            MutableBufferSequence, Handler>::do_completion_impl,
          &receive_operation<
            MutableBufferSequence, Handler>::destroy_impl),
        work_(io_service),
        cancel_token_(cancel_token),
        buffers_(buffers),
        handler_(handler)
    {
    }

  private:
    static void do_completion_impl(operation* op,
        DWORD last_error, size_t bytes_transferred)
    {
      // Take ownership of the operation object.
      typedef receive_operation<MutableBufferSequence, Handler> op_type;
      op_type* handler_op(static_cast<op_type*>(op));
      typedef handler_alloc_traits<Handler, op_type> alloc_traits;
      handler_ptr<alloc_traits> ptr(handler_op->handler_, handler_op);

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
      // Check whether buffers are still valid.
      typename MutableBufferSequence::const_iterator iter
        = handler_op->buffers_.begin();
      typename MutableBufferSequence::const_iterator end
        = handler_op->buffers_.end();
      while (iter != end)
      {
        asio::mutable_buffer buffer(*iter);
        asio::buffer_cast<char*>(buffer);
        ++iter;
      }
#endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)

      // Map non-portable errors to their portable counterparts.
      asio::error_code ec(last_error,
          asio::error::get_system_category());
      if (ec.value() == ERROR_NETNAME_DELETED)
      {
        if (handler_op->cancel_token_.expired())
          ec = asio::error::operation_aborted;
        else
          ec = asio::error::connection_reset;
      }
      else if (ec.value() == ERROR_PORT_UNREACHABLE)
      {
        ec = asio::error::connection_refused;
      }

      // Check for connection closed.
      else if (!ec && bytes_transferred == 0)
      {
        ec = asio::error::eof;
      }

      // Make a copy of the handler so that the memory can be deallocated before
      // the upcall is made.
      Handler handler(handler_op->handler_);

      // Free the memory associated with the handler.
      ptr.reset();

      // Call the handler.
      asio_handler_invoke_helpers::invoke(
          detail::bind_handler(handler, ec, bytes_transferred), &handler);
    }

    static void destroy_impl(operation* op)
    {
      // Take ownership of the operation object.
      typedef receive_operation<MutableBufferSequence, Handler> op_type;
      op_type* handler_op(static_cast<op_type*>(op));
      typedef handler_alloc_traits<Handler, op_type> alloc_traits;
      handler_ptr<alloc_traits> ptr(handler_op->handler_, handler_op);
    }

    asio::io_service::work work_;
    weak_cancel_token_type cancel_token_;
    MutableBufferSequence buffers_;
    Handler handler_;
  };

  // Start an asynchronous receive. The buffer for the data being received
  // must be valid for the lifetime of the asynchronous operation.
  template <typename MutableBufferSequence, typename Handler>
  void async_receive(implementation_type& impl,
      const MutableBufferSequence& buffers,
      socket_base::message_flags flags, Handler handler)
  {
    if (!is_open(impl))
    {
      this->get_io_service().post(bind_handler(handler,
            asio::error::bad_descriptor, 0));
      return;
    }

    // Update the ID of the thread from which cancellation is safe.
    if (impl.safe_cancellation_thread_id_ == 0)
      impl.safe_cancellation_thread_id_ = ::GetCurrentThreadId();
    else if (impl.safe_cancellation_thread_id_ != ::GetCurrentThreadId())
      impl.safe_cancellation_thread_id_ = ~DWORD(0);

    // Allocate and construct an operation to wrap the handler.
    typedef receive_operation<MutableBufferSequence, Handler> value_type;
    typedef handler_alloc_traits<Handler, value_type> alloc_traits;
    raw_handler_ptr<alloc_traits> raw_ptr(handler);
    handler_ptr<alloc_traits> ptr(raw_ptr,
        this->get_io_service(), impl.cancel_token_, buffers, handler);

    // Copy buffers into WSABUF array.
    ::WSABUF bufs[max_buffers];
    typename MutableBufferSequence::const_iterator iter = buffers.begin();
    typename MutableBufferSequence::const_iterator end = buffers.end();
    DWORD i = 0;
    size_t total_buffer_size = 0;
    for (; iter != end && i < max_buffers; ++iter, ++i)
    {
      asio::mutable_buffer buffer(*iter);
      bufs[i].len = static_cast<u_long>(asio::buffer_size(buffer));
      bufs[i].buf = asio::buffer_cast<char*>(buffer);
      total_buffer_size += asio::buffer_size(buffer);
    }

    // A request to receive 0 bytes on a stream socket is a no-op.
    if (impl.protocol_.type() == SOCK_STREAM && total_buffer_size == 0)
    {
      asio::io_service::work work(this->get_io_service());
      ptr.reset();
      asio::error_code error;
      iocp_service_.post(bind_handler(handler, error, 0));
      return;
    }

    // Receive some data.
    DWORD bytes_transferred = 0;
    DWORD recv_flags = flags;
    int result = ::WSARecv(impl.socket_, bufs, i,
        &bytes_transferred, &recv_flags, ptr.get(), 0);
    DWORD last_error = ::WSAGetLastError();
    if (result != 0 && last_error != WSA_IO_PENDING)
    {
      asio::io_service::work work(this->get_io_service());
      ptr.reset();