- The pump's delivered/degraded writes (stream flag, live flag, PublishHealthy /
Degrade) now happen in TryMarkStreamDelivered / TryDegradeStream: one critical
section under _subscriptionLock that re-checks the session generation. A pump
wedged in a subscriber past its last check can no longer report a replaced
session's (down) stream Healthy and make the read path trust it.
- m3: the index and condition tracker are installed in the same lock as the
session + generation and captured under it (TryCaptureSessionState), so a stale
chunk cannot fold into the new session's index.
- Teardown also bumps the generation, so an abandoned pump cannot write over the
shutdown's health either.
- m2: an Agent restart clears the live flag before clearing the index, so reads
go to /current until the re-baseline lands.
Red test: the wedged-pump harness with the new stream failing, plus a positive
control (the current pump's chunk restores Healthy).
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
A pump the lifecycle retired or abandoned that finished after the restart
installed the new session published its stale cursor onto it (PublishAgentCursor
only checked for a null or identical session), so the next pump read its first
chunk as an Agent restart: index cleared, a Bad flicker on every subscribed tag,
a needless re-baseline. The pump now carries the session generation it was
started against; the cursor publish is checked under _subscriptionLock (where the
session install and generation bump are atomic) and a superseded pump also stops
folding late chunks / re-baselines into the new session's index.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Joseph Doherty