ceph/src/boost/libs/asio/include/boost/asio/detail/eventfd_select_interrupter.hpp

   1 //
   2 // detail/eventfd_select_interrupter.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2016 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
  25 namespace boost {
  26 namespace asio {
  27 namespace detail {
  28
  29 class eventfd_select_interrupter
  30 {
  31 public:
  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
  53 private:
  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