std::size_t select_reactor::cancel_timer(timer_queue<Time_Traits>& queue,
    typename timer_queue<Time_Traits>::per_timer_data& timer,
    std::size_t max_cancelled)
{
  riakboost::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;
}

std::size_t epoll_reactor::cancel_timer(timer_queue<Time_Traits>& queue,
    typename timer_queue<Time_Traits>::per_timer_data& timer,
    std::size_t max_cancelled)
{
  mutex::scoped_lock lock(mutex_);
  op_queue<operation> ops;
  std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
  lock.unlock();
  scheduler_.post_deferred_completions(ops);
  return n;
}

std::size_t win_iocp_io_service::cancel_timer(timer_queue<Time_Traits>& queue,
    typename timer_queue<Time_Traits>::per_timer_data& timer)
{
  // If the service has been shut down we silently ignore the cancellation.
  if (::InterlockedExchangeAdd(&shutdown_, 0) != 0)
    return 0;

  mutex::scoped_lock lock(dispatch_mutex_);
  op_queue<win_iocp_operation> ops;
  std::size_t n = queue.cancel_timer(timer, ops);
  post_deferred_completions(ops);
  return n;
}

void kqueue_reactor::schedule_timer(timer_queue<Time_Traits>& queue,
    const typename Time_Traits::time_type& time,
    typename timer_queue<Time_Traits>::per_timer_data& timer, timer_op* op)
{
  boost::asio::detail::mutex::scoped_lock lock(mutex_);

  if (shutdown_)
  {
    io_service_.post_immediate_completion(op);
    return;
  }

  bool earliest = queue.enqueue_timer(time, timer, op);
  io_service_.work_started();
  if (earliest)
    interrupter_.interrupt();
}

void epoll_reactor::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)
{
  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)
    update_timeout();
}

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);
}

void win_iocp_io_service::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)
{
  // If the service has been shut down we silently discard the timer.
  if (::InterlockedExchangeAdd(&shutdown_, 0) != 0)
  {
    post_immediate_completion(op, false);
    return;
  }

  mutex::scoped_lock lock(dispatch_mutex_);

  bool earliest = queue.enqueue_timer(time, timer, op);
  work_started();
  if (earliest)
    update_timeout();
}