asio/detail/pipe_select_interrupter.hpp

0001 //
0002 // detail/pipe_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_PIPE_SELECT_INTERRUPTER_HPP
0012 #define BOOST_ASIO_DETAIL_PIPE_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)
0021 #if !defined(BOOST_ASIO_WINDOWS_RUNTIME)
0022 #if !defined(__CYGWIN__)
0023 #if !defined(__SYMBIAN32__)
0024 #if !defined(BOOST_ASIO_HAS_EVENTFD)
0025
0026 #include <boost/asio/detail/push_options.hpp>
0027
0028 namespace boost {
0029 namespace asio {
0030 namespace detail {
0031
0032 class pipe_select_interrupter
0033 {
0034 public:
0035   // Constructor.
0036   BOOST_ASIO_DECL pipe_select_interrupter();
0037
0038   // Destructor.
0039   BOOST_ASIO_DECL ~pipe_select_interrupter();
0040
0041   // Recreate the interrupter's descriptors. Used after a fork.
0042   BOOST_ASIO_DECL void recreate();
0043
0044   // Interrupt the select call.
0045   BOOST_ASIO_DECL void interrupt();
0046
0047   // Reset the select interrupter. Returns true if the reset was successful.
0048   BOOST_ASIO_DECL bool reset();
0049
0050   // Get the read descriptor to be passed to select.
0051   int read_descriptor() const
0052   {
0053     return read_descriptor_;
0054   }
0055
0056 private:
0057   // Open the descriptors. Throws on error.
0058   BOOST_ASIO_DECL void open_descriptors();
0059
0060   // Close the descriptors.
0061   BOOST_ASIO_DECL void close_descriptors();
0062
0063   // The read end of a connection used to interrupt the select call. This file
0064   // descriptor is passed to select such that when it is time to stop, a single
0065   // byte will be written on the other end of the connection and this
0066   // descriptor will become readable.
0067   int read_descriptor_;
0068
0069   // The write end of a connection used to interrupt the select call. A single
0070   // byte may be written to this to wake up the select which is waiting for the
0071   // other end to become readable.
0072   int write_descriptor_;
0073 };
0074
0075 } // namespace detail
0076 } // namespace asio
0077 } // namespace boost
0078
0079 #include <boost/asio/detail/pop_options.hpp>
0080
0081 #if defined(BOOST_ASIO_HEADER_ONLY)
0082 # include <boost/asio/detail/impl/pipe_select_interrupter.ipp>
0083 #endif // defined(BOOST_ASIO_HEADER_ONLY)
0084
0085 #endif // !defined(BOOST_ASIO_HAS_EVENTFD)
0086 #endif // !defined(__SYMBIAN32__)
0087 #endif // !defined(__CYGWIN__)
0088 #endif // !defined(BOOST_ASIO_WINDOWS_RUNTIME)
0089 #endif // !defined(BOOST_ASIO_WINDOWS)
0090
0091 #endif // BOOST_ASIO_DETAIL_PIPE_SELECT_INTERRUPTER_HPP