From edd7a401e438c4c549037c95e48dcd48a233cb7d Mon Sep 17 00:00:00 2001 From: Peter Geoghegan Date: Mon, 7 Jul 2025 14:11:17 -0400 Subject: [PATCH 1/3] injection points --- src/backend/access/nbtree/nbtsearch.c | 4 ++ src/test/modules/Makefile | 4 +- src/test/modules/meson.build | 1 + src/test/modules/nbtree/.gitignore | 4 ++ src/test/modules/nbtree/Makefile | 28 +++++++++++ .../modules/nbtree/expected/backwards.out | 32 +++++++++++++ src/test/modules/nbtree/meson.build | 17 +++++++ src/test/modules/nbtree/specs/backwards.spec | 46 +++++++++++++++++++ 8 files changed, 134 insertions(+), 2 deletions(-) create mode 100644 src/test/modules/nbtree/.gitignore create mode 100644 src/test/modules/nbtree/Makefile create mode 100644 src/test/modules/nbtree/expected/backwards.out create mode 100644 src/test/modules/nbtree/meson.build create mode 100644 src/test/modules/nbtree/specs/backwards.spec diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c index 4af1ff1e9..c250a4b92 100644 --- a/src/backend/access/nbtree/nbtsearch.c +++ b/src/backend/access/nbtree/nbtsearch.c @@ -21,6 +21,7 @@ #include "miscadmin.h" #include "pgstat.h" #include "storage/predicate.h" +#include "utils/injection_point.h" #include "utils/lsyscache.h" #include "utils/rel.h" @@ -2500,6 +2501,8 @@ _bt_lock_and_validate_left(Relation rel, BlockNumber *blkno, { BlockNumber origblkno = *blkno; /* detects circular links */ + INJECTION_POINT("lock-and-validate-left", NULL); + for (;;) { Buffer buf; @@ -2598,6 +2601,7 @@ _bt_lock_and_validate_left(Relation rel, BlockNumber *blkno, /* Start from scratch with new lastcurrblkno's blkno/prev link */ *blkno = origblkno = opaque->btpo_prev; _bt_relbuf(rel, buf); + INJECTION_POINT("lock-and-validate-new-lastcurrblkno", NULL); } return InvalidBuffer; diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile index aa1d27bbe..06b0de718 100644 --- a/src/test/modules/Makefile +++ b/src/test/modules/Makefile @@ -46,9 +46,9 @@ SUBDIRS = \ ifeq ($(enable_injection_points),yes) -SUBDIRS += injection_points gin typcache +SUBDIRS += injection_points gin nbtree typcache else -ALWAYS_SUBDIRS += injection_points gin typcache +ALWAYS_SUBDIRS += injection_points gin nbtree typcache endif ifeq ($(with_ssl),openssl) diff --git a/src/test/modules/meson.build b/src/test/modules/meson.build index 9de0057bd..54a3e7ba5 100644 --- a/src/test/modules/meson.build +++ b/src/test/modules/meson.build @@ -9,6 +9,7 @@ subdir('gin') subdir('injection_points') subdir('ldap_password_func') subdir('libpq_pipeline') +subdir('nbtree') subdir('oauth_validator') subdir('plsample') subdir('spgist_name_ops') diff --git a/src/test/modules/nbtree/.gitignore b/src/test/modules/nbtree/.gitignore new file mode 100644 index 000000000..5dcb3ff97 --- /dev/null +++ b/src/test/modules/nbtree/.gitignore @@ -0,0 +1,4 @@ +# Generated subdirectories +/log/ +/results/ +/tmp_check/ diff --git a/src/test/modules/nbtree/Makefile b/src/test/modules/nbtree/Makefile new file mode 100644 index 000000000..bdcf80e60 --- /dev/null +++ b/src/test/modules/nbtree/Makefile @@ -0,0 +1,28 @@ +# src/test/modules/nbtree/Makefile + +EXTRA_INSTALL = src/test/modules/injection_points + +ISOLATION = backwards + +ifdef USE_PGXS +PG_CONFIG = pg_config +PGXS := $(shell $(PG_CONFIG) --pgxs) +include $(PGXS) +else +subdir = src/test/modules/nbtree +top_builddir = ../../../.. +include $(top_builddir)/src/Makefile.global + +# XXX: This test is conditional on enable_injection_points in the +# parent Makefile, so we should never get here in the first place if +# injection points are not enabled. But the buildfarm 'misc-check' +# step doesn't pay attention to the if-condition in the parent +# Makefile. To work around that, disable running the test here too. +ifeq ($(enable_injection_points),yes) +include $(top_srcdir)/contrib/contrib-global.mk +else +check: + @echo "injection points are disabled in this build" +endif + +endif diff --git a/src/test/modules/nbtree/expected/backwards.out b/src/test/modules/nbtree/expected/backwards.out new file mode 100644 index 000000000..6b334a2ac --- /dev/null +++ b/src/test/modules/nbtree/expected/backwards.out @@ -0,0 +1,32 @@ +Parsed test spec with 2 sessions + +starting permutation: b_scan i_insert i_detach +step b_scan: SELECT * FROM backwards_scan_tbl WHERE col % 100 = 1 ORDER BY col DESC; +step i_insert: INSERT INTO backwards_scan_tbl SELECT i FROM generate_series(-2000, 700) i; +step i_detach: + SELECT injection_points_detach('lock-and-validate-left'); + SELECT injection_points_wakeup('lock-and-validate-left'); + +injection_points_detach +----------------------- + +(1 row) + +injection_points_wakeup +----------------------- + +(1 row) + +backwards_scan_session: NOTICE: notice triggered for injection point lock-and-validate-new-lastcurrblkno +step b_scan: <... completed> +col +--- +601 +501 +401 +301 +201 +101 + 1 +(7 rows) + diff --git a/src/test/modules/nbtree/meson.build b/src/test/modules/nbtree/meson.build new file mode 100644 index 000000000..20d77077b --- /dev/null +++ b/src/test/modules/nbtree/meson.build @@ -0,0 +1,17 @@ +# Copyright (c) 2022-2025, PostgreSQL Global Development Group + +if not get_option('injection_points') + subdir_done() +endif + +tests += { + 'name': 'nbtree', + 'sd': meson.current_source_dir(), + 'bd': meson.current_build_dir(), + 'isolation': { + 'specs': [ + 'backwards', + ], + 'runningcheck': false, # see syscache-update-pruned + }, +} diff --git a/src/test/modules/nbtree/specs/backwards.spec b/src/test/modules/nbtree/specs/backwards.spec new file mode 100644 index 000000000..780929ee1 --- /dev/null +++ b/src/test/modules/nbtree/specs/backwards.spec @@ -0,0 +1,46 @@ +# Backwards scan isolation test + +setup +{ + CREATE EXTENSION injection_points; + CREATE TABLE backwards_scan_tbl(col int4) WITH (autovacuum_enabled = off); + CREATE INDEX ON backwards_scan_tbl(col); + INSERT INTO backwards_scan_tbl SELECT i FROM generate_series(0, 700) i; +} +setup +{ + VACUUM (FREEZE, DISABLE_PAGE_SKIPPING) backwards_scan_tbl; +} +teardown +{ + DROP EXTENSION injection_points; + DROP TABLE backwards_scan_tbl; +} + +# Wait happens in backwards_scan_session session, wakeup in insert session +# +# The lock-and-validate-new-lastcurrblkno injection point is used for the +# wait. The lock-and-validate-left injection point is used to generate a +# notification that confirms that we have the desired test coverage. +session backwards_scan_session +setup { + SELECT injection_points_set_local(); + SELECT injection_points_attach('lock-and-validate-new-lastcurrblkno', 'notice'); + SELECT injection_points_attach('lock-and-validate-left', 'wait'); + SET enable_seqscan=off; + SET enable_sort=off; +} +step b_scan { SELECT * FROM backwards_scan_tbl WHERE col % 100 = 1 ORDER BY col DESC; } + +session insert_scan_session +step i_detach { + SELECT injection_points_detach('lock-and-validate-left'); + SELECT injection_points_wakeup('lock-and-validate-left'); +} +step i_insert { INSERT INTO backwards_scan_tbl SELECT i FROM generate_series(-2000, 700) i; } + +# Start a backwards scan session that waits "between pages". Meanwhile, a +# concurrent session performs insertions that cause many page splits. When +# the backwards scan session wakes up, it'll have to reason about these +# concurrent page splits the hard way. +permutation b_scan i_insert i_detach -- 2.50.0