asio/detail/socket_select_interrupter.hpp

0001 //
0002 // detail/socket_select_interrupter.hpp
0003 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0004 //
0005 // Copyright (c) 2003-2023 Christopher M. Kohlhoff (chris at kohlhoff dot com)
0006 //
0007 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0008 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0009 //
0010
0011 #ifndef BOOST_ASIO_DETAIL_SOCKET_SELECT_INTERRUPTER_HPP
0012 #define BOOST_ASIO_DETAIL_SOCKET_SELECT_INTERRUPTER_HPP
0013
0014 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
0015 # pragma once
0016 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
0017
0018 #include <boost/asio/detail/config.hpp>
0019
0020 #if !defined(BOOST_ASIO_WINDOWS_RUNTIME)
0021
0022 #if defined(BOOST_ASIO_WINDOWS) \
0023   || defined(__CYGWIN__) \
0024   || defined(__SYMBIAN32__)
0025
0026 #include <boost/asio/detail/socket_types.hpp>
0027
0028 #include <boost/asio/detail/push_options.hpp>
0029
0030 namespace boost {
0031 namespace asio {
0032 namespace detail {
0033
0034 class socket_select_interrupter
0035 {
0036 public:
0037   // Constructor.
0038   BOOST_ASIO_DECL socket_select_interrupter();
0039
0040   // Destructor.
0041   BOOST_ASIO_DECL ~socket_select_interrupter();
0042
0043   // Recreate the interrupter's descriptors. Used after a fork.
0044   BOOST_ASIO_DECL void recreate();
0045
0046   // Interrupt the select call.
0047   BOOST_ASIO_DECL void interrupt();
0048
0049   // Reset the select interrupter. Returns true if the reset was successful.
0050   BOOST_ASIO_DECL bool reset();
0051
0052   // Get the read descriptor to be passed to select.
0053   socket_type read_descriptor() const
0054   {
0055     return read_descriptor_;
0056   }
0057
0058 private:
0059   // Open the descriptors. Throws on error.
0060   BOOST_ASIO_DECL void open_descriptors();
0061
0062   // Close the descriptors.
0063   BOOST_ASIO_DECL void close_descriptors();
0064
0065   // The read end of a connection used to interrupt the select call. This file
0066   // descriptor is passed to select such that when it is time to stop, a single
0067   // byte will be written on the other end of the connection and this
0068   // descriptor will become readable.
0069   socket_type read_descriptor_;
0070
0071   // The write end of a connection used to interrupt the select call. A single
0072   // byte may be written to this to wake up the select which is waiting for the
0073   // other end to become readable.
0074   socket_type write_descriptor_;
0075 };
0076
0077 } // namespace detail
0078 } // namespace asio
0079 } // namespace boost
0080
0081 #include <boost/asio/detail/pop_options.hpp>
0082
0083 #if defined(BOOST_ASIO_HEADER_ONLY)
0084 # include <boost/asio/detail/impl/socket_select_interrupter.ipp>
0085 #endif // defined(BOOST_ASIO_HEADER_ONLY)
0086
0087 #endif // defined(BOOST_ASIO_WINDOWS)
0088        // || defined(__CYGWIN__)
0089        // || defined(__SYMBIAN32__)
0090
0091 #endif // !defined(BOOST_ASIO_WINDOWS_RUNTIME)
0092
0093 #endif // BOOST_ASIO_DETAIL_SOCKET_SELECT_INTERRUPTER_HPP