ceph/src/boost/boost/asio/detail/conditionally_enabled_event.hpp

   1 //
   2 // detail/conditionally_enabled_event.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2019 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_CONDITIONALLY_ENABLED_EVENT_HPP
  12 #define BOOST_ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_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/conditionally_enabled_mutex.hpp>
  20 #include <boost/asio/detail/event.hpp>
  21 #include <boost/asio/detail/noncopyable.hpp>
  22 #include <boost/asio/detail/null_event.hpp>
  23 #include <boost/asio/detail/scoped_lock.hpp>
  24
  25 #include <boost/asio/detail/push_options.hpp>
  26
  27 namespace boost {
  28 namespace asio {
  29 namespace detail {
  30
  31 // Mutex adapter used to conditionally enable or disable locking.
  32 class conditionally_enabled_event
  33   : private noncopyable
  34 {
  35 public:
  36   // Constructor.
  37   conditionally_enabled_event()
  38   {
  39   }
  40
  41   // Destructor.
  42   ~conditionally_enabled_event()
  43   {
  44   }
  45
  46   // Signal the event. (Retained for backward compatibility.)
  47   void signal(conditionally_enabled_mutex::scoped_lock& lock)
  48   {
  49     if (lock.mutex_.enabled_)
  50       event_.signal(lock);
  51   }
  52
  53   // Signal all waiters.
  54   void signal_all(conditionally_enabled_mutex::scoped_lock& lock)
  55   {
  56     if (lock.mutex_.enabled_)
  57       event_.signal_all(lock);
  58   }
  59
  60   // Unlock the mutex and signal one waiter.
  61   void unlock_and_signal_one(
  62       conditionally_enabled_mutex::scoped_lock& lock)
  63   {
  64     if (lock.mutex_.enabled_)
  65       event_.unlock_and_signal_one(lock);
  66   }
  67
  68   // If there's a waiter, unlock the mutex and signal it.
  69   bool maybe_unlock_and_signal_one(
  70       conditionally_enabled_mutex::scoped_lock& lock)
  71   {
  72     if (lock.mutex_.enabled_)
  73       return event_.maybe_unlock_and_signal_one(lock);
  74     else
  75       return false;
  76   }
  77
  78   // Reset the event.
  79   void clear(conditionally_enabled_mutex::scoped_lock& lock)
  80   {
  81     if (lock.mutex_.enabled_)
  82       event_.clear(lock);
  83   }
  84
  85   // Wait for the event to become signalled.
  86   void wait(conditionally_enabled_mutex::scoped_lock& lock)
  87   {
  88     if (lock.mutex_.enabled_)
  89       event_.wait(lock);
  90     else
  91       null_event().wait(lock);
  92   }
  93
  94   // Timed wait for the event to become signalled.
  95   bool wait_for_usec(
  96       conditionally_enabled_mutex::scoped_lock& lock, long usec)
  97   {
  98     if (lock.mutex_.enabled_)
  99       return event_.wait_for_usec(lock, usec);
 100     else
 101       return null_event().wait_for_usec(lock, usec);
 102   }
 103
 104 private:
 105   boost::asio::detail::event event_;
 106 };
 107
 108 } // namespace detail
 109 } // namespace asio
 110 } // namespace boost
 111
 112 #include <boost/asio/detail/pop_options.hpp>
 113
 114 #endif // BOOST_ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP