Module port_park 

phase-436 W7 — installing a port’s park primitive, with the wake-object constraint stated once instead of per board. phase-436 W7 — installing a port’s park primitive, in one place.

Every Rust board entry that wires the seam needs the same three steps and the same non-obvious constraint, so they live here rather than being spelt once per board and drifting.

The constraint. A ParkUntilFn must wait on the executor’s OWN wake object. The backend’s listener signals that one, and spin_once drops its transport drain to non-blocking once a port has parked — so a park on any other object cannot be broken by data arriving, and sleeps out its full deadline with a message already waiting. That is worse than not parking at all, it passes every test, and it is invisible in a quiet run.

Functions

install_port_park

Install park on executor, waiting on the executor’s own wake object.