/** \brief Inner task running, important (promised) tasks.
 *
 * \param pscope Previously created scoped lock.
 * \return True if executed something, false if not.
 */
static bool inner_run_important(boost::mutex::scoped_lock &pscope)
{
  if(tasks_important.empty())
  {
    return false;
  }
  Promise *promise = tasks_important.get();
  pscope.unlock();
  promise->task();
  pscope.lock();
  return true;
}