text: //
  // detail/impl/winrt_timer_scheduler.hpp
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  //
  // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
  //
  // Distributed under the Boost Software License, Version 1.0. (See accompanying
  // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  //
  
  #ifndef BOOST_ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_HPP
  #define BOOST_ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_HPP
  
  #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  # pragma once
  #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  
  #include <boost/asio/detail/config.hpp>
  
  #if defined(BOOST_ASIO_WINDOWS_RUNTIME)
  
  #include <boost/asio/detail/push_options.hpp>
  
  namespace boost {
  namespace asio {
  namespace detail {
  
  template <typename Time_Traits>
  void winrt_timer_scheduler::add_timer_queue(timer_queue<Time_Traits>& queue)
  {
    do_add_timer_queue(queue);
  }
  
  // Remove a timer queue from the reactor.
  template <typename Time_Traits>
  void winrt_timer_scheduler::remove_timer_queue(timer_queue<Time_Traits>& queue)
  {
    do_remove_timer_queue(queue);
  }
  
  template <typename Time_Traits>
  void winrt_timer_scheduler::schedule_timer(timer_queue<Time_Traits>& queue,
      const typename Time_Traits::time_type& time,
      typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op)
  {
    boost::asio::detail::mutex::scoped_lock lock(mutex_);
  
    if (shutdown_)
    {
      io_service_.post_immediate_completion(op, false);
      return;
    }
  
    bool earliest = queue.enqueue_timer(time, timer, op);
    io_service_.work_started();
    if (earliest)
      event_.signal(lock);
  }
  
  template <typename Time_Traits>
  std::size_t winrt_timer_scheduler::cancel_timer(timer_queue<Time_Traits>& queue,
      typename timer_queue<Time_Traits>::per_timer_data& timer,
      std::size_t max_cancelled)
  {
    boost::asio::detail::mutex::scoped_lock lock(mutex_);
    op_queue<operation> ops;
    std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
    lock.unlock();
    io_service_.post_deferred_completions(ops);
    return n;
  }
  
  } // namespace detail
  } // namespace asio
  } // namespace boost
  
  #include <boost/asio/detail/pop_options.hpp>
  
  #endif // defined(BOOST_ASIO_WINDOWS_RUNTIME)
  
  #endif // BOOST_ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_HPP
  