Method dequeue

src/common/PrioritizedQueue.h:278–320

  }

  T dequeue() final {
    ceph_assert(!empty());

    if (!(high_queue.empty())) {
      T ret = std::move(high_queue.rbegin()->second.front().second);
      high_queue.rbegin()->second.pop_front();
      if (high_queue.rbegin()->second.empty()) {
	high_queue.erase(high_queue.rbegin()->first);
      }
      return ret;
    }

    // if there are multiple buckets/subqueues with sufficient tokens,
    // we behave like a strict priority queue among all subqueues that
    // are eligible to run.
    for (typename SubQueues::iterator i = queue.begin();
	 i != queue.end();
	 ++i) {
      ceph_assert(!(i->second.empty()));
      if (i->second.front().first < i->second.num_tokens()) {
	unsigned cost = i->second.front().first;
	i->second.take_tokens(cost);
	T ret = std::move(i->second.front().second);
	i->second.pop_front();
	if (i->second.empty()) {
	  remove_queue(i->first);
	}
	distribute_tokens(cost);
	return ret;
      }
    }

    // if no subqueues have sufficient tokens, we behave like a strict
    // priority queue.
    unsigned cost = queue.rbegin()->second.front().first;
    T ret = std::move(queue.rbegin()->second.front().second);
    queue.rbegin()->second.pop_front();
    if (queue.rbegin()->second.empty()) {
      remove_queue(queue.rbegin()->first);
    }
    distribute_tokens(cost);
    return ret;
  }

  void dump(ceph::Formatter *f) const final {
    f->dump_int("total_priority", total_priority);