Skip-gated AlarmsLiveSmokeTests.Alarms_full_pipeline_round_trip ran
against the dev rig with the flip script firing
TestMachine_001.TestAlarm001 every 10s. Verified:
- Subscribe + 1st PollOnce yield real transition events
- Field-by-field decode correct (provider, group, tag, severity,
UTC timestamp, comment, type)
- SnapshotActiveAlarms reflects current state
- AcknowledgeByName(real identity) -> rc=0
- Pipeline keeps streaming transitions on the 10s cadence post-ack
Three production quirks surfaced and were fixed in
WnWrapAlarmConsumer:
1. SetXmlAlarmQuery is mandatory for reads. Skipping it (per the
earlier discovery-doc recommendation) makes the first
GetXmlCurrentAlarms2 fail with E_FAIL. The doc's claim that the
call is unnecessary because the round-trip echo is mangled was
wrong — mangled echo or not, the call is required.
2. SetXmlAlarmQuery breaks AlarmAckByName on the same consumer
instance (returns -55). Workaround: provision a parallel
"ack-only" wnwrap consumer that runs Initialize → Register →
Subscribe via the v1-prefixed methods, no SetXmlAlarmQuery.
Production WnWrapAlarmConsumer now holds two COM clients;
AcknowledgeByName always dispatches through the ack-only one.
3. AlarmAckByName has v2 (8-arg) and v1 (6-arg) overloads. The v2
8-arg overload returns -55 on this AVEVA build (apparently a
stub); the v1 6-arg overload works. Production now calls the
6-arg overload, discarding the proto's operator_domain and
operator_full_name fields. The proto contract keeps both for
forward-compat if AVEVA fixes the v2 method.
Bonus finding (not fixed here): AlarmAckByGUID throws
NotImplementedException on wnwrap. Reference→GUID lookup that we
initially planned to plumb is therefore not viable; all acks must
go through AlarmAckByName. WorkerAlarmRpcDispatcher.AcknowledgeAsync
already routes references through the by-name path, so this only
affects the GUID-input branch (which the worker tries first if the
input parses as a GUID — that branch will surface
NotImplementedException as MxaccessFailure if a client supplies one).
Threading caveat: wnwrap is ThreadingModel=Apartment, so the
consumer's internal Timer (firing on threadpool threads) blocks on
cross-apartment marshaling without an STA message pump. The smoke
test sidesteps this with pollIntervalMilliseconds=0 (Timer disabled)
+ manual PollOnce calls from the test STA. Production hosting will
route polls through the worker's StaRuntime in a follow-up; PollOnce
is now public so the wire-up is straightforward.
Test counts after this slice:
Worker: 195 pass / 4 skipped (live probes incl. new live smoke) /
1 pre-existing structure-fail (untouched)
Server: 308 pass / 0 fail
Solution builds clean.
docs/AlarmClientDiscovery.md "Live smoke-test discoveries" section
records all five findings.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
a4ed605f74