From 0924b7cc9f1a516df710677b246d26226cd01624 Mon Sep 17 00:00:00 2001
From: "Andrey M. Borodin" <x4mmm@night.local>
Date: Sun, 28 Jan 2024 22:22:22 +0500
Subject: [PATCH v2 2/3] Add wait type for injection points

---
 src/backend/utils/misc/injection_point.c      | 20 ++++++++++
 src/include/utils/injection_point.h           |  1 +
 src/test/modules/injection_points/Makefile    |  1 +
 .../injection_points/injection_points.c       | 16 ++++++++
 .../modules/injection_points/t/001_wait.pl    | 40 +++++++++++++++++++
 5 files changed, 78 insertions(+)
 create mode 100644 src/test/modules/injection_points/t/001_wait.pl

diff --git a/src/backend/utils/misc/injection_point.c b/src/backend/utils/misc/injection_point.c
index 0cf4d51cac..398ef2cf30 100644
--- a/src/backend/utils/misc/injection_point.c
+++ b/src/backend/utils/misc/injection_point.c
@@ -252,6 +252,26 @@ InjectionPointDetach(const char *name)
 #endif
 }
 
+/*
+ * Test if injection point is attached.
+ */
+bool
+InjectionPointIsAttach(const char *name)
+{
+#ifdef USE_INJECTION_POINTS
+	bool		found;
+
+	LWLockAcquire(InjectionPointLock, LW_EXCLUSIVE);
+	hash_search(InjectionPointHash, name, HASH_FIND, &found);
+	LWLockRelease(InjectionPointLock);
+
+	return found;
+
+#else
+	elog(ERROR, "Injection points are not supported by this build");
+#endif
+}
+
 /*
  * Execute an injection point, if defined.
  *
diff --git a/src/include/utils/injection_point.h b/src/include/utils/injection_point.h
index 55524b568f..e07f6b7024 100644
--- a/src/include/utils/injection_point.h
+++ b/src/include/utils/injection_point.h
@@ -33,5 +33,6 @@ extern void InjectionPointAttach(const char *name,
 								 const char *function);
 extern void InjectionPointRun(const char *name);
 extern void InjectionPointDetach(const char *name);
+extern bool InjectionPointIsAttach(const char *name);
 
 #endif							/* INJECTION_POINT_H */
diff --git a/src/test/modules/injection_points/Makefile b/src/test/modules/injection_points/Makefile
index 2cbbae4e0a..543d2ab927 100644
--- a/src/test/modules/injection_points/Makefile
+++ b/src/test/modules/injection_points/Makefile
@@ -7,6 +7,7 @@ DATA = injection_points--1.0.sql
 PGFILEDESC = "injection_points - facility for injection points"
 
 REGRESS = injection_points
+TAP_TESTS = 1
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config
diff --git a/src/test/modules/injection_points/injection_points.c b/src/test/modules/injection_points/injection_points.c
index e843e6594f..fbb30b15ad 100644
--- a/src/test/modules/injection_points/injection_points.c
+++ b/src/test/modules/injection_points/injection_points.c
@@ -18,6 +18,7 @@
 #include "postgres.h"
 
 #include "fmgr.h"
+#include "miscadmin.h"
 #include "storage/lwlock.h"
 #include "storage/shmem.h"
 #include "utils/builtins.h"
@@ -28,6 +29,7 @@ PG_MODULE_MAGIC;
 
 extern PGDLLEXPORT void injection_error(const char *name);
 extern PGDLLEXPORT void injection_notice(const char *name);
+extern PGDLLEXPORT void injection_wait(const char *name);
 
 
 /* Set of callbacks available to be attached to an injection point. */
@@ -43,6 +45,18 @@ injection_notice(const char *name)
 	elog(NOTICE, "notice triggered for injection point %s", name);
 }
 
+void
+injection_wait(const char *name)
+{
+	elog(NOTICE, "waiting triggered for injection point %s", name);
+	do
+	{
+		CHECK_FOR_INTERRUPTS();
+		pg_usleep(1000L);
+	} while (InjectionPointIsAttach(name));
+	elog(NOTICE, "waiting done for injection point %s", name);
+}
+
 /*
  * SQL function for creating an injection point.
  */
@@ -58,6 +72,8 @@ injection_points_attach(PG_FUNCTION_ARGS)
 		function = "injection_error";
 	else if (strcmp(action, "notice") == 0)
 		function = "injection_notice";
+	else if (strcmp(action, "wait") == 0)
+		function = "injection_wait";
 	else
 		elog(ERROR, "incorrect action \"%s\" for injection point creation", action);
 
diff --git a/src/test/modules/injection_points/t/001_wait.pl b/src/test/modules/injection_points/t/001_wait.pl
new file mode 100644
index 0000000000..98f7a8bcef
--- /dev/null
+++ b/src/test/modules/injection_points/t/001_wait.pl
@@ -0,0 +1,40 @@
+
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+
+use Test::More;
+
+my ($node, $result);
+
+$node = PostgreSQL::Test::Cluster->new('injection_points');
+$node->init;
+$node->start;
+$node->safe_psql('postgres', q(CREATE EXTENSION injection_points));
+
+$result = $node->psql('postgres', q(select injection_points_attach('FIRST','wait')));
+is($result, '0', 'wait injection point set');
+
+my $bg = $node->background_psql('postgres');
+
+$bg->query_until(
+	qr/start/, q(
+\echo start
+select injection_points_run('FIRST');
+select injection_points_attach('SECOND','wait');
+));
+
+$result = $node->psql('postgres', q(
+select injection_points_run('SECOND');
+select injection_points_detach('FIRST');
+));
+is($result, '0', 'wait injection point set');
+
+$bg->quit;
+
+$node->stop;
+done_testing();
-- 
2.37.1 (Apple Git-137.1)