1//
2// detail/signal_handler.hpp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2024 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
11#ifndef BOOST_ASIO_DETAIL_SIGNAL_HANDLER_HPP
12#define BOOST_ASIO_DETAIL_SIGNAL_HANDLER_HPP
13
14#if defined(_MSC_VER) && (_MSC_VER >= 1200)
15# pragma once
16#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
17
18#include <boost/asio/detail/config.hpp>
19#include <boost/asio/detail/bind_handler.hpp>
20#include <boost/asio/detail/fenced_block.hpp>
21#include <boost/asio/detail/handler_alloc_helpers.hpp>
22#include <boost/asio/detail/handler_work.hpp>
23#include <boost/asio/detail/memory.hpp>
24#include <boost/asio/detail/signal_op.hpp>
25
26#include <boost/asio/detail/push_options.hpp>
27
28namespace boost {
29namespace asio {
30namespace detail {
31
32template <typename Handler, typename IoExecutor>
33class signal_handler : public signal_op
34{
35public:
36 BOOST_ASIO_DEFINE_HANDLER_PTR(signal_handler);
37
38 signal_handler(Handler& h, const IoExecutor& io_ex)
39 : signal_op(&signal_handler::do_complete),
40 handler_(static_cast<Handler&&>(h)),
41 work_(handler_, io_ex)
42 {
43 }
44
45 static void do_complete(void* owner, operation* base,
46 const boost::system::error_code& /*ec*/,
47 std::size_t /*bytes_transferred*/)
48 {
49 // Take ownership of the handler object.
50 signal_handler* h(static_cast<signal_handler*>(base));
51 ptr p = { boost::asio::detail::addressof(h->handler_), h, h };
52
53 BOOST_ASIO_HANDLER_COMPLETION((*h));
54
55 // Take ownership of the operation's outstanding work.
56 handler_work<Handler, IoExecutor> w(
57 static_cast<handler_work<Handler, IoExecutor>&&>(
58 h->work_));
59
60 // Make a copy of the handler so that the memory can be deallocated before
61 // the upcall is made. Even if we're not about to make an upcall, a
62 // sub-object of the handler may be the true owner of the memory associated
63 // with the handler. Consequently, a local copy of the handler is required
64 // to ensure that any owning sub-object remains valid until after we have
65 // deallocated the memory here.
66 detail::binder2<Handler, boost::system::error_code, int>
67 handler(h->handler_, h->ec_, h->signal_number_);
68 p.h = boost::asio::detail::addressof(handler.handler_);
69 p.reset();
70
71 // Make the upcall if required.
72 if (owner)
73 {
74 fenced_block b(fenced_block::half);
75 BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
76 w.complete(handler, handler.handler_);
77 BOOST_ASIO_HANDLER_INVOCATION_END;
78 }
79 }
80
81private:
82 Handler handler_;
83 handler_work<Handler, IoExecutor> work_;
84};
85
86} // namespace detail
87} // namespace asio
88} // namespace boost
89
90#include <boost/asio/detail/pop_options.hpp>
91
92#endif // BOOST_ASIO_DETAIL_SIGNAL_HANDLER_HPP
93

source code of boost/libs/asio/include/boost/asio/detail/signal_handler.hpp