A unit of per-fixed-step simulation work (§39, verbatim interface).
priority is read once, at registration: the registry keeps its systems
in sorted order rather than re-sorting every step, so mutating priority
after registration has no effect until the system is unregistered and
registered again (WP-1.11 decision — re-sorting per step would cost work in
the hot path and make the order depend on when a field happened to change).
A unit of per-fixed-step simulation work (§39, verbatim interface).
priorityis read once, at registration: the registry keeps its systems in sorted order rather than re-sorting every step, so mutatingpriorityafter registration has no effect until the system is unregistered and registered again (WP-1.11 decision — re-sorting per step would cost work in the hot path and make the order depend on when a field happened to change).