void thr::thr_init()
{
  if(!privileged_thread.isUninitialized())
  {
    std::stringstream sstr;
    sstr << "thread system already initialized";
    BOOST_THROW_EXCEPTION(std::runtime_error(sstr.str()));
  }

  privileged_thread.acquire();
  workers_active.addLast(&privileged_thread);
}