RegisterNotificationAsync published a refused registration into
NativeRegistrations under ConnectGate with NextRetryUtc = MinValue; the
SubscribeAsync caller booked the refusal backoff (NoteDeadFailure refused:
true) only after the gate was released and after its WARN. A probe tick in
that window took the gate, saw the registration as due, and retried it at
once - the CI flake in A_rearm_during_an_in_flight_retry_is_not_lost
("AttemptsFor(\"MAIN.T\") should be 1 but was 2").
RegisterNotificationAsync now books the failure (refusal backoff, or the
comms-class every-tick retry) before it publishes the dead registration, still
under the gate. The caller no longer books the refusal a second time (that
would double the backoff); its comms-class booking is idempotent and stays.
Tests: TwinCATCapturingLogger gains an OnWarning hook. A logger that holds
the refusal WARN for ten probe intervals forces the window open, so
A_rearm_during_an_in_flight_retry_is_not_lost exercises it on every run, and
the new A_refused_registration_is_published_with_its_backoff_already_set
pins the backoff (booked once, not doubled).
Pass rate of A_rearm_during_an_in_flight_retry_is_not_lost:
- before, unmodified test: 40/40 runs, plus 200/200 in-process repeats under
CPU load (the natural window is a few instructions wide; the flake is rare);
- before, window held open: 0/32 (deterministic failure, "should be 1 but
was 2");
- after, window held open: 40/40.
Full TwinCAT suite 663/663 at AKKA_TEST_TIMEFACTOR 1 and 3.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Joseph Doherty
f0992394b6