From 09ae4ae0fef8156da0f0026aadcd67307e1dc6f6 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Fri, 10 Nov 2023 13:54:11 +0200
Subject: [PATCH 1/3] Add test_dsa module.

This covers basic calls within a single backend process, and a test
that uses a different resource owner. The resource owner test
demonstrates that calling dsa_allocate() or dsa_get_address() while in
a different resource owner than in the dsa_create/attach call causes a
segfault. I think that's a bug.

This resource owner issue was originally found by Alexander Lakhin,
exposed by my large ResourceOwner rewrite commit.

Reported-by: Alexander Lakhin
Discussion: https://www.postgresql.org/message-id/11b70743-c5f3-3910-8e5b-dd6c115ff829%40gmail.com
---
 src/test/modules/Makefile                     |   1 +
 src/test/modules/meson.build                  |   1 +
 src/test/modules/test_dsa/Makefile            |  23 ++++
 .../modules/test_dsa/expected/test_dsa.out    |  13 ++
 src/test/modules/test_dsa/meson.build         |  33 +++++
 src/test/modules/test_dsa/sql/test_dsa.sql    |   4 +
 src/test/modules/test_dsa/test_dsa--1.0.sql   |  12 ++
 src/test/modules/test_dsa/test_dsa.c          | 115 ++++++++++++++++++
 src/test/modules/test_dsa/test_dsa.control    |   4 +
 9 files changed, 206 insertions(+)
 create mode 100644 src/test/modules/test_dsa/Makefile
 create mode 100644 src/test/modules/test_dsa/expected/test_dsa.out
 create mode 100644 src/test/modules/test_dsa/meson.build
 create mode 100644 src/test/modules/test_dsa/sql/test_dsa.sql
 create mode 100644 src/test/modules/test_dsa/test_dsa--1.0.sql
 create mode 100644 src/test/modules/test_dsa/test_dsa.c
 create mode 100644 src/test/modules/test_dsa/test_dsa.control

diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 738b715e792..a18e4d28a04 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -17,6 +17,7 @@ SUBDIRS = \
 		  test_copy_callbacks \
 		  test_custom_rmgrs \
 		  test_ddl_deparse \
+		  test_dsa \
 		  test_extensions \
 		  test_ginpostinglist \
 		  test_integerset \
diff --git a/src/test/modules/meson.build b/src/test/modules/meson.build
index d4828dc44d5..4e83c0f8d74 100644
--- a/src/test/modules/meson.build
+++ b/src/test/modules/meson.build
@@ -14,6 +14,7 @@ subdir('test_bloomfilter')
 subdir('test_copy_callbacks')
 subdir('test_custom_rmgrs')
 subdir('test_ddl_deparse')
+subdir('test_dsa')
 subdir('test_extensions')
 subdir('test_ginpostinglist')
 subdir('test_integerset')
diff --git a/src/test/modules/test_dsa/Makefile b/src/test/modules/test_dsa/Makefile
new file mode 100644
index 00000000000..77583464dca
--- /dev/null
+++ b/src/test/modules/test_dsa/Makefile
@@ -0,0 +1,23 @@
+# src/test/modules/test_dsa/Makefile
+
+MODULE_big = test_dsa
+OBJS = \
+	$(WIN32RES) \
+	test_dsa.o
+PGFILEDESC = "test_dsa - test code for dynamic shared memory areas"
+
+EXTENSION = test_dsa
+DATA = test_dsa--1.0.sql
+
+REGRESS = test_dsa
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_dsa
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_dsa/expected/test_dsa.out b/src/test/modules/test_dsa/expected/test_dsa.out
new file mode 100644
index 00000000000..266010e77fe
--- /dev/null
+++ b/src/test/modules/test_dsa/expected/test_dsa.out
@@ -0,0 +1,13 @@
+CREATE EXTENSION test_dsa;
+SELECT test_dsa_basic();
+ test_dsa_basic 
+----------------
+ 
+(1 row)
+
+SELECT test_dsa_resowners();
+ test_dsa_resowners 
+--------------------
+ 
+(1 row)
+
diff --git a/src/test/modules/test_dsa/meson.build b/src/test/modules/test_dsa/meson.build
new file mode 100644
index 00000000000..21738290ad5
--- /dev/null
+++ b/src/test/modules/test_dsa/meson.build
@@ -0,0 +1,33 @@
+# Copyright (c) 2022-2023, PostgreSQL Global Development Group
+
+test_dsa_sources = files(
+  'test_dsa.c',
+)
+
+if host_system == 'windows'
+  test_dsa_sources += rc_lib_gen.process(win32ver_rc, extra_args: [
+    '--NAME', 'test_dsa',
+    '--FILEDESC', 'test_dsa - test code for dynamic shared memory areas',])
+endif
+
+test_dsa = shared_module('test_dsa',
+  test_dsa_sources,
+  kwargs: pg_test_mod_args,
+)
+test_install_libs += test_dsa
+
+test_install_data += files(
+  'test_dsa.control',
+  'test_dsa--1.0.sql',
+)
+
+tests += {
+  'name': 'test_dsa',
+  'sd': meson.current_source_dir(),
+  'bd': meson.current_build_dir(),
+  'regress': {
+    'sql': [
+      'test_dsa',
+    ],
+  },
+}
diff --git a/src/test/modules/test_dsa/sql/test_dsa.sql b/src/test/modules/test_dsa/sql/test_dsa.sql
new file mode 100644
index 00000000000..c3d8db94372
--- /dev/null
+++ b/src/test/modules/test_dsa/sql/test_dsa.sql
@@ -0,0 +1,4 @@
+CREATE EXTENSION test_dsa;
+
+SELECT test_dsa_basic();
+SELECT test_dsa_resowners();
diff --git a/src/test/modules/test_dsa/test_dsa--1.0.sql b/src/test/modules/test_dsa/test_dsa--1.0.sql
new file mode 100644
index 00000000000..2904cb23525
--- /dev/null
+++ b/src/test/modules/test_dsa/test_dsa--1.0.sql
@@ -0,0 +1,12 @@
+/* src/test/modules/test_dsa/test_dsa--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_dsa" to load this file. \quit
+
+CREATE FUNCTION test_dsa_basic()
+	RETURNS pg_catalog.void
+	AS 'MODULE_PATHNAME' LANGUAGE C;
+
+CREATE FUNCTION test_dsa_resowners()
+	RETURNS pg_catalog.void
+	AS 'MODULE_PATHNAME' LANGUAGE C;
diff --git a/src/test/modules/test_dsa/test_dsa.c b/src/test/modules/test_dsa/test_dsa.c
new file mode 100644
index 00000000000..b3753b58577
--- /dev/null
+++ b/src/test/modules/test_dsa/test_dsa.c
@@ -0,0 +1,115 @@
+/*--------------------------------------------------------------------------
+ *
+ * test_dsa.c
+ *		Test dynamic shared memory areas (DSAs)
+ *
+ * Copyright (c) 2022-2023, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		src/test/modules/test_dsa/test_dsa.c
+ *
+ * -------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "fmgr.h"
+#include "utils/dsa.h"
+#include "storage/lwlock.h"
+#include "utils/resowner.h"
+
+PG_MODULE_MAGIC;
+
+/* Test basic DSA functionality */
+PG_FUNCTION_INFO_V1(test_dsa_basic);
+Datum
+test_dsa_basic(PG_FUNCTION_ARGS)
+{
+	int			tranche_id;
+	dsa_area   *a;
+	dsa_pointer p[100];
+
+	/* XXX: this tranche is leaked */
+	tranche_id = LWLockNewTrancheId();
+	LWLockRegisterTranche(tranche_id, "test_dsa");
+
+	a = dsa_create(tranche_id);
+	for (int i = 0; i < 100; i++)
+	{
+		p[i] = dsa_allocate(a, 1000);
+		snprintf(dsa_get_address(a, p[i]), 1000, "foobar%d", i);
+	}
+
+	for (int i = 0; i < 100; i++)
+	{
+		char buf[100];
+
+		snprintf(buf, 100, "foobar%d", i);
+		if (strcmp(dsa_get_address(a, p[i]), buf) != 0)
+			elog(ERROR, "no match");
+	}
+
+	for (int i = 0; i < 100; i++)
+	{
+		dsa_free(a, p[i]);
+	}
+
+	dsa_detach(a);
+
+	PG_RETURN_VOID();
+}
+
+/* Test using DSA across different resource owners */
+PG_FUNCTION_INFO_V1(test_dsa_resowners);
+Datum
+test_dsa_resowners(PG_FUNCTION_ARGS)
+{
+	int			tranche_id;
+	dsa_area   *a;
+	dsa_pointer p[10000];
+	ResourceOwner oldowner;
+	ResourceOwner childowner;
+
+	/* XXX: this tranche is leaked */
+	tranche_id = LWLockNewTrancheId();
+	LWLockRegisterTranche(tranche_id, "test_dsa");
+
+	/* Create DSA in parent resource owner */
+	a = dsa_create(tranche_id);
+
+	/* Switch to child resource owner, and do a bunch of allocations in the
+	 * DSA */
+	oldowner = CurrentResourceOwner;
+	childowner = ResourceOwnerCreate(oldowner, "test_dsa temp owner");
+	CurrentResourceOwner = childowner;
+
+	for (int i = 0; i < 10000; i++)
+	{
+		p[i] = dsa_allocate(a, 1000);
+		snprintf(dsa_get_address(a, p[i]), 1000, "foobar%d", i);
+	}
+
+	/*
+	 * Free them all. Not necessary, but demonstrates that you get a crash
+	 * even if you free all the allocations that you made while in the child
+	 * resource owner. The allocations are not "owned" by the resource owner.
+	 */
+	for (int i = 0; i < 100; i++)
+		dsa_free(a, p[i]);
+
+	/* Release the child resource owner */
+	CurrentResourceOwner = oldowner;
+	ResourceOwnerRelease(childowner,
+						 RESOURCE_RELEASE_BEFORE_LOCKS,
+						 true, false);
+	ResourceOwnerRelease(childowner,
+						 RESOURCE_RELEASE_LOCKS,
+						 true, false);
+	ResourceOwnerRelease(childowner,
+						 RESOURCE_RELEASE_AFTER_LOCKS,
+						 true, false);
+	ResourceOwnerDelete(childowner);
+
+	dsa_detach(a);
+
+	PG_RETURN_VOID();
+}
diff --git a/src/test/modules/test_dsa/test_dsa.control b/src/test/modules/test_dsa/test_dsa.control
new file mode 100644
index 00000000000..ac9674b2193
--- /dev/null
+++ b/src/test/modules/test_dsa/test_dsa.control
@@ -0,0 +1,4 @@
+comment = 'Test code for dynamic shared memory areas'
+default_version = '1.0'
+module_pathname = '$libdir/test_dsa'
+relocatable = true
-- 
2.39.2

