test: cover pg_task.limit/run concurrency caps in all three suites

RekGRpth · claude · RekGRpth · commit 5e76afedaff2 · 2026-07-29T15:38:06.000+05:00
work_sleep()'s claiming query LIMIT clause is LEAST(run - currently
held, "limit") - both were left at their generous defaults (limit
1000, run INT_MAX) by every existing test, so neither had ever
actually constrained anything. Add a case per file that lowers each
GUC to 1 via ALTER SYSTEM (work_sleep reads them live through
current_setting(), so a session-level SET wouldn't reach the
dispatcher) and asserts that with three long-running tasks inserted
at once, at least one gets dispatched and at least one stays behind
in PLAN - proving the cap actually throttles intake.

Same claiming logic runs once in work_sleep() regardless of local/
spi/remote, so this duplicates identical SQL across all three files
rather than exercising different code paths per file, unlike the
earlier per-mode cases.

Co-Authored-By: Claude Sonnet 5 &lt;noreply@anthropic.com&gt;
diff --git a/expected/local.out b/expected/local.out
@@ -46,3 +46,9 @@ t
 t
 t|t
 t
+t
+t|t
+t
+t
+t|t
+t
diff --git a/expected/remote.out b/expected/remote.out
@@ -49,3 +49,9 @@ t
 t|t
 t
 t
+t
+t|t
+t
+t
+t|t
+t
diff --git a/expected/spi.out b/expected/spi.out
@@ -45,3 +45,9 @@ t
 t|t
 t
 t
+t|t
+t
+t
+t|t
+t
+t
diff --git a/sql/local.sql b/sql/local.sql
@@ -255,3 +255,35 @@ DO $body$ BEGIN
     END LOOP;
 END;$body$ LANGUAGE plpgsql;
 SELECT output = '"1","text",<NULL>' AS format_ok FROM task WHERE "group" = '29' AND plan > :ct::timestamp;
+DELETE FROM task WHERE "group" IN ('30', '31', '32');
+ALTER SYSTEM SET pg_task."limit" = 1;
+SELECT pg_reload_conf();
+INSERT INTO task ("group", input) VALUES ('30', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('31', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('32', 'SELECT pg_sleep(5) AS a');
+DO $$ BEGIN PERFORM pg_sleep(2); END $$;
+SELECT count(*) FILTER (WHERE state != 'PLAN') >= 1 AS some_dispatched, count(*) FILTER (WHERE state = 'PLAN') >= 1 AS some_capped FROM task WHERE "group" IN ('30', '31', '32') AND plan > :ct::timestamp;
+ALTER SYSTEM RESET pg_task."limit";
+SELECT pg_reload_conf();
+DO $body$ BEGIN
+    FOR i IN 1..30 LOOP
+        IF (SELECT count(*) FROM task WHERE "group" IN ('30', '31', '32') AND state NOT IN ('DONE', 'GONE', 'FAIL')) = 0 THEN EXIT; END IF;
+        PERFORM pg_sleep(1);
+    END LOOP;
+END;$body$ LANGUAGE plpgsql;
+DELETE FROM task WHERE "group" IN ('30', '31', '32');
+ALTER SYSTEM SET pg_task.run = 1;
+SELECT pg_reload_conf();
+INSERT INTO task ("group", input) VALUES ('30', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('31', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('32', 'SELECT pg_sleep(5) AS a');
+DO $$ BEGIN PERFORM pg_sleep(2); END $$;
+SELECT count(*) FILTER (WHERE state != 'PLAN') >= 1 AS some_dispatched, count(*) FILTER (WHERE state = 'PLAN') >= 1 AS some_capped FROM task WHERE "group" IN ('30', '31', '32') AND plan > :ct::timestamp;
+ALTER SYSTEM RESET pg_task.run;
+SELECT pg_reload_conf();
+DO $body$ BEGIN
+    FOR i IN 1..30 LOOP
+        IF (SELECT count(*) FROM task WHERE "group" IN ('30', '31', '32') AND state NOT IN ('DONE', 'GONE', 'FAIL')) = 0 THEN EXIT; END IF;
+        PERFORM pg_sleep(1);
+    END LOOP;
+END;$body$ LANGUAGE plpgsql;
diff --git a/sql/remote.sql b/sql/remote.sql
@@ -277,3 +277,35 @@ DO $body$ BEGIN
     END LOOP;
 END;$body$ LANGUAGE plpgsql;
 SELECT output = '"1","text",<NULL>' AS format_ok FROM task WHERE "group" = '29' AND plan > :ct::timestamp;
+DELETE FROM task WHERE "group" IN ('30', '31', '32');
+ALTER SYSTEM SET pg_task."limit" = 1;
+SELECT pg_reload_conf();
+INSERT INTO task ("group", input, remote) VALUES ('30', 'SELECT pg_sleep(5) AS a', 'application_name=test');
+INSERT INTO task ("group", input, remote) VALUES ('31', 'SELECT pg_sleep(5) AS a', 'application_name=test');
+INSERT INTO task ("group", input, remote) VALUES ('32', 'SELECT pg_sleep(5) AS a', 'application_name=test');
+DO $$ BEGIN PERFORM pg_sleep(2); END $$;
+SELECT count(*) FILTER (WHERE state != 'PLAN') >= 1 AS some_dispatched, count(*) FILTER (WHERE state = 'PLAN') >= 1 AS some_capped FROM task WHERE "group" IN ('30', '31', '32') AND plan > :ct::timestamp;
+ALTER SYSTEM RESET pg_task."limit";
+SELECT pg_reload_conf();
+DO $body$ BEGIN
+    FOR i IN 1..30 LOOP
+        IF (SELECT count(*) FROM task WHERE "group" IN ('30', '31', '32') AND state NOT IN ('DONE', 'GONE', 'FAIL')) = 0 THEN EXIT; END IF;
+        PERFORM pg_sleep(1);
+    END LOOP;
+END;$body$ LANGUAGE plpgsql;
+DELETE FROM task WHERE "group" IN ('30', '31', '32');
+ALTER SYSTEM SET pg_task.run = 1;
+SELECT pg_reload_conf();
+INSERT INTO task ("group", input, remote) VALUES ('30', 'SELECT pg_sleep(5) AS a', 'application_name=test');
+INSERT INTO task ("group", input, remote) VALUES ('31', 'SELECT pg_sleep(5) AS a', 'application_name=test');
+INSERT INTO task ("group", input, remote) VALUES ('32', 'SELECT pg_sleep(5) AS a', 'application_name=test');
+DO $$ BEGIN PERFORM pg_sleep(2); END $$;
+SELECT count(*) FILTER (WHERE state != 'PLAN') >= 1 AS some_dispatched, count(*) FILTER (WHERE state = 'PLAN') >= 1 AS some_capped FROM task WHERE "group" IN ('30', '31', '32') AND plan > :ct::timestamp;
+ALTER SYSTEM RESET pg_task.run;
+SELECT pg_reload_conf();
+DO $body$ BEGIN
+    FOR i IN 1..30 LOOP
+        IF (SELECT count(*) FROM task WHERE "group" IN ('30', '31', '32') AND state NOT IN ('DONE', 'GONE', 'FAIL')) = 0 THEN EXIT; END IF;
+        PERFORM pg_sleep(1);
+    END LOOP;
+END;$body$ LANGUAGE plpgsql;
diff --git a/sql/spi.sql b/sql/spi.sql
@@ -257,5 +257,37 @@ DO $body$ BEGIN
     END LOOP;
 END;$body$ LANGUAGE plpgsql;
 SELECT output = '"1","text",<NULL>' AS format_ok FROM task WHERE "group" = '29' AND plan > :ct::timestamp;
+DELETE FROM task WHERE "group" IN ('30', '31', '32');
+ALTER SYSTEM SET pg_task."limit" = 1;
+SELECT pg_reload_conf();
+INSERT INTO task ("group", input) VALUES ('30', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('31', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('32', 'SELECT pg_sleep(5) AS a');
+DO $$ BEGIN PERFORM pg_sleep(2); END $$;
+SELECT count(*) FILTER (WHERE state != 'PLAN') >= 1 AS some_dispatched, count(*) FILTER (WHERE state = 'PLAN') >= 1 AS some_capped FROM task WHERE "group" IN ('30', '31', '32') AND plan > :ct::timestamp;
+ALTER SYSTEM RESET pg_task."limit";
+SELECT pg_reload_conf();
+DO $body$ BEGIN
+    FOR i IN 1..30 LOOP
+        IF (SELECT count(*) FROM task WHERE "group" IN ('30', '31', '32') AND state NOT IN ('DONE', 'GONE', 'FAIL')) = 0 THEN EXIT; END IF;
+        PERFORM pg_sleep(1);
+    END LOOP;
+END;$body$ LANGUAGE plpgsql;
+DELETE FROM task WHERE "group" IN ('30', '31', '32');
+ALTER SYSTEM SET pg_task.run = 1;
+SELECT pg_reload_conf();
+INSERT INTO task ("group", input) VALUES ('30', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('31', 'SELECT pg_sleep(5) AS a');
+INSERT INTO task ("group", input) VALUES ('32', 'SELECT pg_sleep(5) AS a');
+DO $$ BEGIN PERFORM pg_sleep(2); END $$;
+SELECT count(*) FILTER (WHERE state != 'PLAN') >= 1 AS some_dispatched, count(*) FILTER (WHERE state = 'PLAN') >= 1 AS some_capped FROM task WHERE "group" IN ('30', '31', '32') AND plan > :ct::timestamp;
+ALTER SYSTEM RESET pg_task.run;
+SELECT pg_reload_conf();
+DO $body$ BEGIN
+    FOR i IN 1..30 LOOP
+        IF (SELECT count(*) FROM task WHERE "group" IN ('30', '31', '32') AND state NOT IN ('DONE', 'GONE', 'FAIL')) = 0 THEN EXIT; END IF;
+        PERFORM pg_sleep(1);
+    END LOOP;
+END;$body$ LANGUAGE plpgsql;
 ALTER SYSTEM RESET pg_task.spi;
 SELECT pg_reload_conf();

Original file line number	Diff line number	Diff line change
`@@ -46,3 +46,9 @@ t`
`46`	`46`	`t`
`47`	`47`	`t\|t`
`48`	`48`	`t`
	`49`	`+t`
	`50`	`+t\|t`
	`51`	`+t`
	`52`	`+t`
	`53`	`+t\|t`
	`54`	`+t`
Original file line number	Diff line number	Diff line change
`@@ -49,3 +49,9 @@ t`
`49`	`49`	`t\|t`
`50`	`50`	`t`
`51`	`51`	`t`
	`52`	`+t`
	`53`	`+t\|t`
	`54`	`+t`
	`55`	`+t`
	`56`	`+t\|t`
	`57`	`+t`
Original file line number	Diff line number	Diff line change
`@@ -45,3 +45,9 @@ t`
`45`	`45`	`t\|t`
`46`	`46`	`t`
`47`	`47`	`t`
	`48`	`+t\|t`
	`49`	`+t`
	`50`	`+t`
	`51`	`+t\|t`
	`52`	`+t`
	`53`	`+t`