descriptor_read_op.hpp 3.8 KB

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  1. //
  2. // detail/descriptor_read_op.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2013 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. #ifndef BOOST_ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP
  11. #define BOOST_ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP
  12. #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  13. # pragma once
  14. #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  15. #include <boost/asio/detail/config.hpp>
  16. #if !defined(BOOST_ASIO_WINDOWS) && !defined(__CYGWIN__)
  17. #include <boost/asio/detail/addressof.hpp>
  18. #include <boost/asio/detail/bind_handler.hpp>
  19. #include <boost/asio/detail/buffer_sequence_adapter.hpp>
  20. #include <boost/asio/detail/descriptor_ops.hpp>
  21. #include <boost/asio/detail/fenced_block.hpp>
  22. #include <boost/asio/detail/reactor_op.hpp>
  23. #include <boost/asio/detail/push_options.hpp>
  24. namespace boost {
  25. namespace asio {
  26. namespace detail {
  27. template <typename MutableBufferSequence>
  28. class descriptor_read_op_base : public reactor_op
  29. {
  30. public:
  31. descriptor_read_op_base(int descriptor,
  32. const MutableBufferSequence& buffers, func_type complete_func)
  33. : reactor_op(&descriptor_read_op_base::do_perform, complete_func),
  34. descriptor_(descriptor),
  35. buffers_(buffers)
  36. {
  37. }
  38. static bool do_perform(reactor_op* base)
  39. {
  40. descriptor_read_op_base* o(static_cast<descriptor_read_op_base*>(base));
  41. buffer_sequence_adapter<boost::asio::mutable_buffer,
  42. MutableBufferSequence> bufs(o->buffers_);
  43. return descriptor_ops::non_blocking_read(o->descriptor_,
  44. bufs.buffers(), bufs.count(), o->ec_, o->bytes_transferred_);
  45. }
  46. private:
  47. int descriptor_;
  48. MutableBufferSequence buffers_;
  49. };
  50. template <typename MutableBufferSequence, typename Handler>
  51. class descriptor_read_op
  52. : public descriptor_read_op_base<MutableBufferSequence>
  53. {
  54. public:
  55. BOOST_ASIO_DEFINE_HANDLER_PTR(descriptor_read_op);
  56. descriptor_read_op(int descriptor,
  57. const MutableBufferSequence& buffers, Handler& handler)
  58. : descriptor_read_op_base<MutableBufferSequence>(
  59. descriptor, buffers, &descriptor_read_op::do_complete),
  60. handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler))
  61. {
  62. }
  63. static void do_complete(io_service_impl* owner, operation* base,
  64. const boost::system::error_code& /*ec*/,
  65. std::size_t /*bytes_transferred*/)
  66. {
  67. // Take ownership of the handler object.
  68. descriptor_read_op* o(static_cast<descriptor_read_op*>(base));
  69. ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
  70. BOOST_ASIO_HANDLER_COMPLETION((o));
  71. // Make a copy of the handler so that the memory can be deallocated before
  72. // the upcall is made. Even if we're not about to make an upcall, a
  73. // sub-object of the handler may be the true owner of the memory associated
  74. // with the handler. Consequently, a local copy of the handler is required
  75. // to ensure that any owning sub-object remains valid until after we have
  76. // deallocated the memory here.
  77. detail::binder2<Handler, boost::system::error_code, std::size_t>
  78. handler(o->handler_, o->ec_, o->bytes_transferred_);
  79. p.h = boost::asio::detail::addressof(handler.handler_);
  80. p.reset();
  81. // Make the upcall if required.
  82. if (owner)
  83. {
  84. fenced_block b(fenced_block::half);
  85. BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
  86. boost_asio_handler_invoke_helpers::invoke(handler, handler.handler_);
  87. BOOST_ASIO_HANDLER_INVOCATION_END;
  88. }
  89. }
  90. private:
  91. Handler handler_;
  92. };
  93. } // namespace detail
  94. } // namespace asio
  95. } // namespace boost
  96. #include <boost/asio/detail/pop_options.hpp>
  97. #endif // !defined(BOOST_ASIO_WINDOWS) && !defined(__CYGWIN__)
  98. #endif // BOOST_ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP