Method queue

src/common/WorkQueue.h:258–264

    }
    
    bool queue(T *item) {
      pool->_lock.lock();
      bool r = _enqueue(item);
      pool->_cond.notify_one();
      pool->_lock.unlock();
      return r;
    }
    void dequeue(T *item) {
      pool->_lock.lock();
      _dequeue(item);