Struct NetEventObserver 

pub struct NetEventObserver { /* private fields */ }

A running path-event observer. Construct one with start; the OS watcher runs until the observer is dropped, which stops the thread (Linux / BSD) or cancels the change callbacks (Windows).

Implementations

impl NetEventObserver

pub fn start(iface: Option<String>) -> Self

Start watching for path events. iface names the interface to read the MTU from; None auto-detects the first non-loopback up interface (the usual single-uplink case). Watcher startup is best-effort: if the OS notification source cannot be opened the observer still constructs and simply never fires, so a caller need not handle a failure.

pub fn path_shift(&self) -> f32

Decaying path-shift signal (0..=1): high just after a route / carrier / MTU event, fading with a fixed half-life. Fused as a path_shift source.

pub fn pmtu(&self) -> Option<u16>

Current egress-interface MTU in bytes, or None if unknown / the platform does not read it. Reported to the peer in a PmtuFrame.

pub fn event_count(&self) -> u64

Total path events observed since start (monotonic). A nonzero value is the durable proof the watcher fired, independent of the shift decay.

pub fn backend(&self) -> &'static str

Backend identifier (for diagnostics).

pub fn inject_event(&self)

Synthetically record a path event, as if the OS had announced a route / carrier change. Drives the --sim-path-event demo and the unit tests on a host where flapping a real interface is impractical; the production path is the OS watcher.

pub fn inject_pmtu(&self, mtu: u16)

Synthetically report a path MTU, recording an event if it is a drop - the same path a polled MTU decrease would take. For tests / demos.