Build persist_apply_pump_run()/persist_apply_pump_kick() -- the
ordered walk from last_applied_lsn+1 through committed_lsn, applying
every entry via apply_committed_entry() regardless of commit mode.
This is the first live (non-replay) consumer of that dispatch
function. Kick is wired into commit_resolve_pending() (the single
choke point all 6 internal committed_lsn-advancing paths funnel
through, discovered in task 1.2), dispatched via
vtask_enq_classified(VTASK_LIVE_BLOCK) with a CAS-coalesced
fire-and-forget trigger.
Fixes the two hazards flagged since task 4.1 as required before
going live:
1. Double-append: a thread-local call-provenance guard
(t_apply_seam_notifying) prevents persist_job_hook_fun/
persist_queue_hook_fun/persist_worker_hook_fun from re-appending
entries the apply pump itself just applied, while preserving
job_ctrl's legitimate live command-path appends (a naive
detail-based filter would have broken SIGCONT/SIGSTOP). Also
closes an undocumented instance of the same hazard in the
queue/worker hook functions.
2. Merge-staleness: record_job_fail_fact/postdone's fact recording
previously baked a receipt-time-computed final job state into the
WAL entry, which goes stale under deferred apply -- a FINISH
followed shortly by an ordinary post-exec FAIL could silently
clobber a correct DONE completion with a stale RUN|EXIT|PERR, no
guard catching it. Fixed by repurposing wal_jobstate_t's unused
_pad field to carry just enough data (FAIL's stage) to recompute
against the job's actual current state at apply time via the real
apply_job_fail_transition()/new apply_job_postdone_transition()
guard cores, instead of overwriting with a stale absolute value.
Backward compatible: _pad==0 (all prior data) routes to the same
legacy overwrite behavior.
Also fixes bug-1409 (unbounded busy-loop in apply_pump_drain when
committed_lsn advances without a corresponding on-disk entry) and a
genuine test-flakiness hazard (a second, independent apply-pump
kicker from the fsync_worker thread that existing tests didn't
account for).
Two pre-existing tests in test_commit_barrier_reply.c now fail as
expected -- their own assertions state "no job may be constructed
until task 6's apply pump exists," now correctly invalidated by this
task landing; updating them is task 7.3's explicit job.
Rongsong Shen
2fa955b92e