Sean,
there is no single queue that maintains order of arrival of requests in Jetty. Different requests will arrive on different connections, which may be handled by different selectors which run entirely independently of each other. Even if they are on a single selector, the order they are selected is entirely dependent in the implementation of the Set iterator, which has no guarantee about the order.
The design of jetty is specifically done so as to avoid synchronisation points that can become congested. Jetty doesn't distribute requests to Random threads. The requests start off already distributed among random threads which do the selection, IO and parsing. There is no queue of requests, no centralised point of contention to base an ordering on. There is no way of telling if one request was received before or after another. This is deliberately by design and required so that jetty can scale.
We do set a timestamp on each request, but only to millisecond accuracy, so you can have several requests arriving at the same time, but even with nanosecond accuracy that would still be possible on a multi-core machine for 2 CPUs to receive requests from the same client at precisely the same time. If you want an ordering, then you will need to create a data structure based on client IP that your application can synchronise on soon after receiving the request.
regards
