Boost::asio async_write_some 对比 async_send

Question

刚才才注意到boost::asio中的async_write_some和async_send（二次重载）函数完全一样：

async_write_some 防守：

...
template <typename ConstBufferSequence, typename WriteHandler>
  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
      void (boost::system::error_code, std::size_t))
  async_write_some(const ConstBufferSequence& buffers,
      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
  {
    // If you get an error on the following line it means that your handler does
    // not meet the documented type requirements for a WriteHandler.
    BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;

    return this->get_service().async_send(this->get_implementation(),
        buffers, 0, BOOST_ASIO_MOVE_CAST(WriteHandler)(handler));
  }
...

async_send定义：

...
template <typename ConstBufferSequence, typename WriteHandler>
  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
      void (boost::system::error_code, std::size_t))
  async_send(const ConstBufferSequence& buffers,
      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
  {
    // If you get an error on the following line it means that your handler does
    // not meet the documented type requirements for a WriteHandler.
    BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;

    return this->get_service().async_send(
        this->get_implementation(), buffers, 0,
        BOOST_ASIO_MOVE_CAST(WriteHandler)(handler));
  }
...

为什么boost::asio库中有两个相同的函数？有什么历史原因吗？

谢谢！

Answer 1

它们提供两种不同的抽象：

stream.async_write_some() 允许一般写入异步流 I/O 对象。例如，此抽象允许更高级别的 async_write() composed operation to generically write to ip::tcp::socket, ssl:stream, serial_port, etc. The async_write_some() member function is part of the AsyncWriteStream 类型要求。
socket.async_send() 允许一个人在不考虑协议的情况下一般地写入套接字。例如，这种抽象允许一般写入 ip::tcp::socket、ip::udp::socket、local::*_protocol::socket 和 generic::*_protocol::socket。 socket.async_send() 模型的存在与已建立的 BSD 套接字密切相关 API.

Boost::asio async_write_some 对比 async_send

Boost::asio async_write_some vs async_send

c++

boost-asio

send