Joseph Doherty
058d8d529f
DisposeAsync is the third path that completes the outbound, staging and event
channels, but unlike MarkClosed and SetFaulted it left _state untouched. A
client disposed while still Ready therefore kept reporting
IsTerminalState() == false, so a read loop already inside DispatchEnvelope when
the staging channel was completed took StageWorkerEvent's overflow arm: a
spurious ProtocolViolation fault, a worker-event-staging overflow metric, a
redundant kill and a WorkerStopped("ProtocolViolation") metric during an
intentional teardown — on exactly the path an operator inspects after a failed
SessionManager.OpenSessionAsync.
DisposeAsync now takes _syncRoot once, claims _disposed there, and transitions
to Closed only when the state is not already Closed or Faulted, so a
dispose-after-fault keeps Faulted and a double dispose is a no-op. Because the
transition is now real, the dispose path records the worker stop through the
existing RecordWorkerStoppedOnce latch, which also stops the running-worker
gauge leaking when a Ready client is disposed without a prior close or fault.
MarkClosed is deliberately not reused: it would overwrite Faulted with Closed
and would re-run a teardown sequence DisposeAsync performs itself.
The StageWorkerEvent XML doc now names all three completion paths.
Test: DisposeAsync_WhileWorkerIsEmittingEvents_ClosesWithoutFaultingOrOverflowing
disposes a Ready client mid-event-stream and asserts Closed state, zero faults,
zero queue overflows, zero kills and exactly one recorded worker exit. It fails
on the pre-fix code.