1//
2// detail/eventfd_select_interrupter.hpp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6// Copyright (c) 2008 Roelof Naude (roelof.naude at gmail dot com)
7//
8// Distributed under the Boost Software License, Version 1.0. (See accompanying
9// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
10//
11
12#ifndef BOOST_ASIO_DETAIL_EVENTFD_SELECT_INTERRUPTER_HPP
13#define BOOST_ASIO_DETAIL_EVENTFD_SELECT_INTERRUPTER_HPP
14
15#if defined(_MSC_VER) && (_MSC_VER >= 1200)
16# pragma once
17#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
18
19#include <boost/asio/detail/config.hpp>
20
21#if defined(BOOST_ASIO_HAS_EVENTFD)
22
23#include <boost/asio/detail/push_options.hpp>
24
25namespace boost {
26namespace asio {
27namespace detail {
28
29class eventfd_select_interrupter
30{
31public:
32 // Constructor.
33 BOOST_ASIO_DECL eventfd_select_interrupter();
34
35 // Destructor.
36 BOOST_ASIO_DECL ~eventfd_select_interrupter();
37
38 // Recreate the interrupter's descriptors. Used after a fork.
39 BOOST_ASIO_DECL void recreate();
40
41 // Interrupt the select call.
42 BOOST_ASIO_DECL void interrupt();
43
44 // Reset the select interrupt. Returns true if the call was interrupted.
45 BOOST_ASIO_DECL bool reset();
46
47 // Get the read descriptor to be passed to select.
48 int read_descriptor() const
49 {
50 return read_descriptor_;
51 }
52
53private:
54 // Open the descriptors. Throws on error.
55 BOOST_ASIO_DECL void open_descriptors();
56
57 // Close the descriptors.
58 BOOST_ASIO_DECL void close_descriptors();
59
60 // The read end of a connection used to interrupt the select call. This file
61 // descriptor is passed to select such that when it is time to stop, a single
62 // 64bit value will be written on the other end of the connection and this
63 // descriptor will become readable.
64 int read_descriptor_;
65
66 // The write end of a connection used to interrupt the select call. A single
67 // 64bit non-zero value may be written to this to wake up the select which is
68 // waiting for the other end to become readable. This descriptor will only
69 // differ from the read descriptor when a pipe is used.
70 int write_descriptor_;
71};
72
73} // namespace detail
74} // namespace asio
75} // namespace boost
76
77#include <boost/asio/detail/pop_options.hpp>
78
79#if defined(BOOST_ASIO_HEADER_ONLY)
80# include <boost/asio/detail/impl/eventfd_select_interrupter.ipp>
81#endif // defined(BOOST_ASIO_HEADER_ONLY)
82
83#endif // defined(BOOST_ASIO_HAS_EVENTFD)
84
85#endif // BOOST_ASIO_DETAIL_EVENTFD_SELECT_INTERRUPTER_HPP
86

source code of boost/boost/asio/detail/eventfd_select_interrupter.hpp