reactive_null_buffers_op.hpp 2.6 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788
  1. //
  2. // detail/reactive_null_buffers_op.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2015 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 ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP
  11. #define ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP
  12. #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  13. # pragma once
  14. #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  15. #include "asio/detail/config.hpp"
  16. #include "asio/detail/addressof.hpp"
  17. #include "asio/detail/fenced_block.hpp"
  18. #include "asio/detail/handler_alloc_helpers.hpp"
  19. #include "asio/detail/handler_invoke_helpers.hpp"
  20. #include "asio/detail/reactor_op.hpp"
  21. #include "asio/detail/push_options.hpp"
  22. namespace asio {
  23. namespace detail {
  24. template <typename Handler>
  25. class reactive_null_buffers_op : public reactor_op
  26. {
  27. public:
  28. ASIO_DEFINE_HANDLER_PTR(reactive_null_buffers_op);
  29. reactive_null_buffers_op(Handler& handler)
  30. : reactor_op(&reactive_null_buffers_op::do_perform,
  31. &reactive_null_buffers_op::do_complete),
  32. handler_(ASIO_MOVE_CAST(Handler)(handler))
  33. {
  34. }
  35. static bool do_perform(reactor_op*)
  36. {
  37. return true;
  38. }
  39. static void do_complete(io_service_impl* owner, operation* base,
  40. const asio::error_code& /*ec*/,
  41. std::size_t /*bytes_transferred*/)
  42. {
  43. // Take ownership of the handler object.
  44. reactive_null_buffers_op* o(static_cast<reactive_null_buffers_op*>(base));
  45. ptr p = { asio::detail::addressof(o->handler_), o, o };
  46. ASIO_HANDLER_COMPLETION((o));
  47. // Make a copy of the handler so that the memory can be deallocated before
  48. // the upcall is made. Even if we're not about to make an upcall, a
  49. // sub-object of the handler may be the true owner of the memory associated
  50. // with the handler. Consequently, a local copy of the handler is required
  51. // to ensure that any owning sub-object remains valid until after we have
  52. // deallocated the memory here.
  53. detail::binder2<Handler, asio::error_code, std::size_t>
  54. handler(o->handler_, o->ec_, o->bytes_transferred_);
  55. p.h = asio::detail::addressof(handler.handler_);
  56. p.reset();
  57. // Make the upcall if required.
  58. if (owner)
  59. {
  60. fenced_block b(fenced_block::half);
  61. ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
  62. asio_handler_invoke_helpers::invoke(handler, handler.handler_);
  63. ASIO_HANDLER_INVOCATION_END;
  64. }
  65. }
  66. private:
  67. Handler handler_;
  68. };
  69. } // namespace detail
  70. } // namespace asio
  71. #include "asio/detail/pop_options.hpp"
  72. #endif // ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP