Networking-audit deferred plan §2. The host↔client offset was measured once
at connect; an NTP step or slow drift silently corrupted the clock-based
jump-to-live signal, the ABR one-way-delay signal, and every latency stat —
4a3b1ae2's disarm backstop stopped the IDR storm but lost the detector for
the session. Now the client re-estimates mid-stream and recovers it.
- quic: ClockResync — the connect-time 8-round probe/echo estimate as a
select!-driven state machine (rounds matched by echoed t1, stale batches
ignored), plus accept_resync (batch min-RTT ≤ max(2 ms, 1.5× connect RTT)
so a congested window can never bias the offset). No wire change: the
host has always answered ClockProbe at any time on the control stream.
- client: the offset lives in an Arc<AtomicI64> seeded at connect; the
control task re-probes every 60 s and immediately after the pump's FIRST
no-op clock flush (the "clock stepped under me" signal, sent on the next
report tick). On apply: store, reset stale_frames/noop_clock_flushes,
re-arm the clock detector if a step had disarmed it. The disarm heuristic
stays as the final backstop. Public NativeClient::clock_offset_ns keeps
the connect-time value (ABI untouched); new clock_offset_now_ns() /
clock_offset_shared() expose the live value.
- consumers migrated to the live offset: pf-client-core session stats, the
pf-presenter e2e stamp, Windows session/render, Android feeder/drain/
DisplayTracker (the tracker holds the shared handle, not the client, so
the leaked render-callback refcount can't pin the session).
- probe: --clock-resync runs a second full handshake mid-connection and
asserts a sane, consistent estimate. Live against the local canary host:
offsets 8646/2139 ns, disagreement 6 µs, 8/8 rounds — OK.
Unit tests cover the round collection, stale-echo rejection, batch restart,
min-RTT selection, and the acceptance guard. cargo ndk check green.
Remaining manual validation: `sudo date -s "+2 sec"` on a live streaming
client → expect one no-op flush, a re-sync, re-armed detector, no IDR pulse.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
enricobuehler
d4467a44e2