Wire exit detection for the four directly-observable optional children so
the supervisor FSM's ChildExited edge fires at runtime. A runtime
child-liveness mpsc channel carries a Child on exit: the DNS task and the
two TUN threads self-report when their body returns, and a 2s poll monitor
reports mDNS and Nostr via new is_finished accessors. The rx_loop gains a
select arm that steps the FSM and republishes health (Degraded, since a
running node always has at least one transport up). Transports and worker
pools expose no runtime-exit signal and are left for a follow-up.
Adds LanRendezvous::is_finished and NostrRendezvous::is_finished; the
latter treats a shutdown-taken connect_task as finished so the monitor
terminates after a stop instead of polling forever.
Add an operator-visible Draining phase on daemon shutdown. On the
shutdown signal the node broadcasts Disconnect to all peers, then keeps
serving for a bounded window - up to node.drain_timeout_secs (default 2s),
exiting early once all peers are gone - before tearing down. This lets
in-flight traffic settle and peers observe the disconnect before the
transports close, rather than the previous immediate teardown.
The lifecycle FSM gains a Draining state plus Drain/DrainDeadlineElapsed
events; the run loop observes the shutdown signal and transitions to
draining in place - one continuous loop, so the channel receivers are
never destructively cancelled. The published NodeState gains a Draining
variant, visible via control queries during the window. The immediate
stop() path used by tests and non-daemon callers is unchanged: it still
tears down immediately with no drain wait.
The reconciler-gate actions the drain emits are no-ops until the peering
reconciler lands and consumes them.
Introduce a sans-IO lifecycle supervisor: a synchronous step(event) ->
[action] state machine (SupervisorFsm) that authors the substrate-child
spawn and teardown order, plus an owner struct (Supervisor) holding the
substrate runtime fields and embedding the FSM. The substrate-lifecycle
fields leave Node's flat list into the owner - state, packet_tx, the TUN
reader/writer handles + shutdown fd + channels, the DNS task + identity
channel, the Nostr/LAN rendezvous drivers, and the encrypt/decrypt worker
pools; the dataplane keeps packet_rx.
start()/stop() become the driver executing the FSM's SpawnChild/StopChild
actions: same children, same order, same warn/debug-and-continue on
optional failures, same logs, same NodeState transitions. Behavior- and
wire-neutral. The only determinism change is that transports now tear
down in ascending-id order, previously nondeterministic HashMap iteration.
The bounded Draining phase and the Running{Full|Degraded} health split
land as separate follow-on commits.
Forward-merge the dataplane/session concept-home reorganization onto
the next line. The moved files carry next's (XX-line) content; the one
hand-resolved surface is src/peer/active.rs, where the source-location
citation sits in different surrounding text than on the master line —
resolved by keeping next's body and applying the same node/session.rs
-> node/session/mod.rs citation update.
Reorganize the node module tree by concept rather than by
message-handling verb, as the first step of the node runtime
decomposition. Pure relocation: no wire, config, metric, or log
semantics change; the lib test count is unchanged (1577 passed).
Moves (git mv, 100% rename similarity):
- handlers/{forwarding,rx_loop,connected_udp,dispatch,encrypted}.rs
-> node/dataplane/ — the whole RX hot path (the select! run loop,
transit/local forwarding, the link-message router, the RX decrypt
path with responder K-bit cutover + roam writes, and connected-UDP
fast-path activation) now lives in one home.
- node/session.rs -> node/session/mod.rs — establishes the session
concept home for the data/state types. The message-behavior file
handlers/session.rs stays put for now (folds in with the later FSP
session step).
The IK/XX-divergent establishment files (handlers/{handshake,rekey,
timeout}.rs) and the deferred-home files (handlers/{mmp,lookup}.rs)
deliberately stay in handlers/, to move once rather than twice.
Every module is reached through impl Node methods, so no call site or
re-export shim was needed. Updated in lockstep with the moves: the
module_path!-derived tracing targets in the two mesh-lab compose-trace
overlays, a structural test's include_str! source path, doc-comments
in proto/routing and the mesh-lab docs, and the stale source-location
citations (node/handlers/{forwarding,rx_loop,encrypted}.rs and
node/session.rs) in doc-comments and the discovery design doc.
Johnathan Corgan