test(db): lock probes read only their own database's locks

pg_locks is the whole server's: under the parallel lane a worker's own advisory claim on the same playlist id, or its own lock wait, was counted by another worker's probe (a leak reported where there was none, a commit made before the second tab blocked).
2026-10-25 13:51:26 +01:00
parent 2e1934689f
commit 13f65b4844
2 changed files with 14 additions and 4 deletions
@@ -1105,10 +1105,16 @@ def test_two_overlapping_reorders_never_share_a_slot(db, as_user):

        worker = threading.Thread(target=second_tab)
        worker.start()
-        # Commit A only once B is blocked on a row lock, so B's read is the stale snapshot.
+        # Commit A only once B is blocked on a row lock, so B's read is the stale snapshot. pg_locks is
+        # the whole server's: only a wait in this database is B's (a parallel worker's is not).
        waiting = 0
        for _ in range(200):
-            waiting = probe.scalar(text("SELECT count(*) FROM pg_locks WHERE NOT granted"))
+            waiting = probe.scalar(
+                text(
+                    "SELECT count(*) FROM pg_locks WHERE NOT granted AND pid IN"
+                    " (SELECT pid FROM pg_stat_activity WHERE datname = current_database())"
+                )
+            )
            probe.rollback()
            if waiting:
                break