on_scheduler_join()'s full job resync and sched_job_new_fun()'s
incremental per-commit push both hold c->sched.lock for their entire
body, making concurrent delivery of the same jobid structurally
impossible -- confirmed by direct code reading, no live repro needed.
This also fully explains the previously-unexplained "redelivery
storm" (up to 18x per jobid): every scheduler reconnect triggers a
full resync of the whole job set, and the scheduler's connection
already flaps repeatedly under heavy load (found earlier this
session), so N flaps produce N redundant resyncs with no race
involved. All scheduler-side and controller-side push-path candidates
are now exhausted; the actual stale-reader for j->submit remains
unfound after 9 sessions.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XYdtrEWWZfKRRGED7raEYg
Rongsong Shen
1fc08d74f5