From fa42213d4af6bc0dce5b8e9bffeef9afa20b8dd8 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 25 Sep 2025 13:29:02 -0400 Subject: Add minimal sleep to stats isolation test functions. The functions test_stat_func() and test_stat_func2() had empty function bodies, so that they took very little time to run. This made it possible that on machines with relatively low timer resolution the functions could return before the clock advanced, making the test fail (as seen on buildfarm members fruitcrow and hamerkop). To avoid that, pg_sleep for 10us during the functions. As far as we can tell, all current hardware has clock resolution much less than that. (The current implementation of pg_sleep will round it up to 1ms anyway, but someday that might get improved.) Author: Michael Banck Reviewed-by: Tom Lane Discussion: https://postgr.es/m/68d413a3.a70a0220.24c74c.8be9@mx.google.com Backpatch-through: 15 --- src/test/isolation/specs/stats.spec | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/test/isolation/specs/stats.spec b/src/test/isolation/specs/stats.spec index 5b922d788cc..64247c40875 100644 --- a/src/test/isolation/specs/stats.spec +++ b/src/test/isolation/specs/stats.spec @@ -6,10 +6,13 @@ setup INSERT INTO test_stat_tab(key, value) VALUES('k0', 1); INSERT INTO test_stat_oid(name, oid) VALUES('test_stat_tab', 'test_stat_tab'::regclass); - CREATE FUNCTION test_stat_func() RETURNS VOID LANGUAGE plpgsql AS $$BEGIN END;$$; + -- include 10us sleep to ensure that runtime measures as more than zero + CREATE FUNCTION test_stat_func() RETURNS VOID LANGUAGE plpgsql AS + $$BEGIN PERFORM pg_sleep(10e-6); END;$$; INSERT INTO test_stat_oid(name, oid) VALUES('test_stat_func', 'test_stat_func'::regproc); - CREATE FUNCTION test_stat_func2() RETURNS VOID LANGUAGE plpgsql AS $$BEGIN END;$$; + CREATE FUNCTION test_stat_func2() RETURNS VOID LANGUAGE plpgsql AS + $$BEGIN PERFORM pg_sleep(10e-6); END;$$; INSERT INTO test_stat_oid(name, oid) VALUES('test_stat_func2', 'test_stat_func2'::regproc); CREATE TABLE test_slru_stats(slru TEXT, stat TEXT, value INT); -- cgit v1.2.3