reactive_null_buffers_op.hpp 3.0 KB

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  1. //
  2. // detail/reactive_null_buffers_op.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2022 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/bind_handler.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/handler_work.hpp"
  21. #include "asio/detail/memory.hpp"
  22. #include "asio/detail/reactor_op.hpp"
  23. #include "asio/detail/push_options.hpp"
  24. namespace asio {
  25. namespace detail {
  26. template <typename Handler, typename IoExecutor>
  27. class reactive_null_buffers_op : public reactor_op
  28. {
  29. public:
  30. ASIO_DEFINE_HANDLER_PTR(reactive_null_buffers_op);
  31. reactive_null_buffers_op(const asio::error_code& success_ec,
  32. Handler& handler, const IoExecutor& io_ex)
  33. : reactor_op(success_ec, &reactive_null_buffers_op::do_perform,
  34. &reactive_null_buffers_op::do_complete),
  35. handler_(ASIO_MOVE_CAST(Handler)(handler)),
  36. work_(handler_, io_ex)
  37. {
  38. }
  39. static status do_perform(reactor_op*)
  40. {
  41. return done;
  42. }
  43. static void do_complete(void* owner, operation* base,
  44. const asio::error_code& /*ec*/,
  45. std::size_t /*bytes_transferred*/)
  46. {
  47. // Take ownership of the handler object.
  48. reactive_null_buffers_op* o(static_cast<reactive_null_buffers_op*>(base));
  49. ptr p = { asio::detail::addressof(o->handler_), o, o };
  50. ASIO_HANDLER_COMPLETION((*o));
  51. // Take ownership of the operation's outstanding work.
  52. handler_work<Handler, IoExecutor> w(
  53. ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
  54. o->work_));
  55. // Make a copy of the handler so that the memory can be deallocated before
  56. // the upcall is made. Even if we're not about to make an upcall, a
  57. // sub-object of the handler may be the true owner of the memory associated
  58. // with the handler. Consequently, a local copy of the handler is required
  59. // to ensure that any owning sub-object remains valid until after we have
  60. // deallocated the memory here.
  61. detail::binder2<Handler, asio::error_code, std::size_t>
  62. handler(o->handler_, o->ec_, o->bytes_transferred_);
  63. p.h = asio::detail::addressof(handler.handler_);
  64. p.reset();
  65. // Make the upcall if required.
  66. if (owner)
  67. {
  68. fenced_block b(fenced_block::half);
  69. ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
  70. w.complete(handler, handler.handler_);
  71. ASIO_HANDLER_INVOCATION_END;
  72. }
  73. }
  74. private:
  75. Handler handler_;
  76. handler_work<Handler, IoExecutor> work_;
  77. };
  78. } // namespace detail
  79. } // namespace asio
  80. #include "asio/detail/pop_options.hpp"
  81. #endif // ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP