pub fn inflight_dec(loc: DeviceLocation)Expand description
Decrement the in-flight async-op count for loc — called when an A4b
completion handle RETIRES (its Drop). Underflow-saturating: if the
slot is missing or already 0 this is a no-op, so an unexpected extra
dec can never wrap the count to u32::MAX and poison future
scheduling. (Under the balance invariant — every inc is matched by
exactly one dec via the handle’s Drop — this saturation never
actually fires; it is pure defense.)