signal_handler.hpp 2.9 KB

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  1. //
  2. // detail/signal_handler.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2019 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_SIGNAL_HANDLER_HPP
  11. #define BOOST_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 <boost/asio/detail/config.hpp>
  16. #include <boost/asio/detail/bind_handler.hpp>
  17. #include <boost/asio/detail/fenced_block.hpp>
  18. #include <boost/asio/detail/handler_alloc_helpers.hpp>
  19. #include <boost/asio/detail/handler_invoke_helpers.hpp>
  20. #include <boost/asio/detail/handler_work.hpp>
  21. #include <boost/asio/detail/memory.hpp>
  22. #include <boost/asio/detail/signal_op.hpp>
  23. #include <boost/asio/detail/push_options.hpp>
  24. namespace boost {
  25. namespace asio {
  26. namespace detail {
  27. template <typename Handler, typename IoExecutor>
  28. class signal_handler : public signal_op
  29. {
  30. public:
  31. BOOST_ASIO_DEFINE_HANDLER_PTR(signal_handler);
  32. signal_handler(Handler& h, const IoExecutor& io_ex)
  33. : signal_op(&signal_handler::do_complete),
  34. handler_(BOOST_ASIO_MOVE_CAST(Handler)(h)),
  35. io_executor_(io_ex)
  36. {
  37. handler_work<Handler, IoExecutor>::start(handler_, io_executor_);
  38. }
  39. static void do_complete(void* owner, operation* base,
  40. const boost::system::error_code& /*ec*/,
  41. std::size_t /*bytes_transferred*/)
  42. {
  43. // Take ownership of the handler object.
  44. signal_handler* h(static_cast<signal_handler*>(base));
  45. ptr p = { boost::asio::detail::addressof(h->handler_), h, h };
  46. handler_work<Handler, IoExecutor> w(h->handler_, h->io_executor_);
  47. BOOST_ASIO_HANDLER_COMPLETION((*h));
  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, boost::system::error_code, int>
  55. handler(h->handler_, h->ec_, h->signal_number_);
  56. p.h = boost::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. BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
  63. w.complete(handler, handler.handler_);
  64. BOOST_ASIO_HANDLER_INVOCATION_END;
  65. }
  66. }
  67. private:
  68. Handler handler_;
  69. IoExecutor io_executor_;
  70. };
  71. } // namespace detail
  72. } // namespace asio
  73. } // namespace boost
  74. #include <boost/asio/detail/pop_options.hpp>
  75. #endif // BOOST_ASIO_DETAIL_SIGNAL_HANDLER_HPP