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

   1 //
   2 // detail/conditionally_enabled_event.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2020 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   // Unlock the mutex and signal one waiter who may destroy us.
  69   void unlock_and_signal_one_for_destruction(
  70       conditionally_enabled_mutex::scoped_lock& lock)
  71   {
  72     if (lock.mutex_.enabled_)
  73       event_.unlock_and_signal_one(lock);
  74   }
  75
  76   // If there's a waiter, unlock the mutex and signal it.
  77   bool maybe_unlock_and_signal_one(
  78       conditionally_enabled_mutex::scoped_lock& lock)
  79   {
  80     if (lock.mutex_.enabled_)
  81       return event_.maybe_unlock_and_signal_one(lock);
  82     else
  83       return false;
  84   }
  85
  86   // Reset the event.
  87   void clear(conditionally_enabled_mutex::scoped_lock& lock)
  88   {
  89     if (lock.mutex_.enabled_)
  90       event_.clear(lock);
  91   }
  92
  93   // Wait for the event to become signalled.
  94   void wait(conditionally_enabled_mutex::scoped_lock& lock)
  95   {
  96     if (lock.mutex_.enabled_)
  97       event_.wait(lock);
  98     else
  99       null_event().wait(lock);
 100   }
 101
 102   // Timed wait for the event to become signalled.
 103   bool wait_for_usec(
 104       conditionally_enabled_mutex::scoped_lock& lock, long usec)
 105   {
 106     if (lock.mutex_.enabled_)
 107       return event_.wait_for_usec(lock, usec);
 108     else
 109       return null_event().wait_for_usec(lock, usec);
 110   }
 111
 112 private:
 113   boost::asio::detail::event event_;
 114 };
 115
 116 } // namespace detail
 117 } // namespace asio
 118 } // namespace boost
 119
 120 #include <boost/asio/detail/pop_options.hpp>
 121
 122 #endif // BOOST_ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP