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

   1 //
   2 // detail/win_event.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2016 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_WIN_EVENT_HPP
  12 #define BOOST_ASIO_DETAIL_WIN_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
  20 #if defined(BOOST_ASIO_WINDOWS)
  21
  22 #include <boost/asio/detail/assert.hpp>
  23 #include <boost/asio/detail/noncopyable.hpp>
  24 #include <boost/asio/detail/socket_types.hpp>
  25
  26 #include <boost/asio/detail/push_options.hpp>
  27
  28 namespace boost {
  29 namespace asio {
  30 namespace detail {
  31
  32 class win_event
  33   : private noncopyable
  34 {
  35 public:
  36   // Constructor.
  37   BOOST_ASIO_DECL win_event();
  38
  39   // Destructor.
  40   BOOST_ASIO_DECL ~win_event();
  41
  42   // Signal the event. (Retained for backward compatibility.)
  43   template <typename Lock>
  44   void signal(Lock& lock)
  45   {
  46     this->signal_all(lock);
  47   }
  48
  49   // Signal all waiters.
  50   template <typename Lock>
  51   void signal_all(Lock& lock)
  52   {
  53     BOOST_ASIO_ASSERT(lock.locked());
  54     (void)lock;
  55     state_ |= 1;
  56     ::SetEvent(events_[0]);
  57   }
  58
  59   // Unlock the mutex and signal one waiter.
  60   template <typename Lock>
  61   void unlock_and_signal_one(Lock& lock)
  62   {
  63     BOOST_ASIO_ASSERT(lock.locked());
  64     state_ |= 1;
  65     bool have_waiters = (state_ > 1);
  66     lock.unlock();
  67     if (have_waiters)
  68       ::SetEvent(events_[1]);
  69   }
  70
  71   // If there's a waiter, unlock the mutex and signal it.
  72   template <typename Lock>
  73   bool maybe_unlock_and_signal_one(Lock& lock)
  74   {
  75     BOOST_ASIO_ASSERT(lock.locked());
  76     state_ |= 1;
  77     if (state_ > 1)
  78     {
  79       lock.unlock();
  80       ::SetEvent(events_[1]);
  81       return true;
  82     }
  83     return false;
  84   }
  85
  86   // Reset the event.
  87   template <typename Lock>
  88   void clear(Lock& lock)
  89   {
  90     BOOST_ASIO_ASSERT(lock.locked());
  91     (void)lock;
  92     ::ResetEvent(events_[0]);
  93     state_ &= ~std::size_t(1);
  94   }
  95
  96   // Wait for the event to become signalled.
  97   template <typename Lock>
  98   void wait(Lock& lock)
  99   {
 100     BOOST_ASIO_ASSERT(lock.locked());
 101     while ((state_ & 1) == 0)
 102     {
 103       state_ += 2;
 104       lock.unlock();
 105 #if defined(BOOST_ASIO_WINDOWS_APP)
 106       ::WaitForMultipleObjectsEx(2, events_, false, INFINITE, false);
 107 #else // defined(BOOST_ASIO_WINDOWS_APP)
 108       ::WaitForMultipleObjects(2, events_, false, INFINITE);
 109 #endif // defined(BOOST_ASIO_WINDOWS_APP)
 110       lock.lock();
 111       state_ -= 2;
 112     }
 113   }
 114
 115 private:
 116   HANDLE events_[2];
 117   std::size_t state_;
 118 };
 119
 120 } // namespace detail
 121 } // namespace asio
 122 } // namespace boost
 123
 124 #include <boost/asio/detail/pop_options.hpp>
 125
 126 #if defined(BOOST_ASIO_HEADER_ONLY)
 127 # include <boost/asio/detail/impl/win_event.ipp>
 128 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 129
 130 #endif // defined(BOOST_ASIO_WINDOWS)
 131
 132 #endif // BOOST_ASIO_DETAIL_WIN_EVENT_HPP