在FIFO Qeueing系统中，实现优先级消息传递的最佳方式是什么

For message-oriented middleware that does not consistently support priority messages (such as AMQP) what is the best way to implement priority consumption when queues have only FIFO semantics? The general use case would be a system in which consumers receive messages of a higher priority before messages of a lower priority when a large backlog of messages exists in Queue(s).For message-oriented middleware that does not c