signal_handler.hpp 2.7 KB

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