It's turtles all the way down. At some point, it's _not really_ a queue. For example imagine a computer program to fetch the contents of a list of URLs. Perhap

It's turtles all the way down. At some point, it's _not really_ a queue. For example imagine a computer program to fetch the contents of a list of URLs. Perhaps it makes some number of parallel requests. If the URLs are hard coded, e.g.: fetch("https://news.ycombinator.com/") fetch("https://bbc.co.uk/") fetch("https://archive.org/") ... When the maximum concurrency is reached (which could simply be 1) and all requests are blocking, then back-pressure is applied. The callers wait before submitting more work. In this example the queue is the code, and the program counter acts represents the head of the queue. I wouldn't regularly refer to that as a queue. Perhaps instead it reads a list of entries from a file. The queue's state can be represented by file offset. And so on. Computers are by definition carry out sequences of operations. A sequence can be viewed as a queue. Everything is a queue. So yes, ignore requests and make the caller implement their own queue _is a completely correct take_ in a sense, but I don't find it productive.