v2-0001-Add-InjectionPointList-to-retrieve-list-of-inject.patch

From f84213eab2fc324f0e92ca7c55e164da6b2a74ee Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Tue, 22 Apr 2025 12:59:30 +0900
Subject: [PATCH v2 1/3] Add InjectionPointList() to retrieve list of injection
 points

This hides the internals of the shmem array lookup, allocating the
result in a palloc'd array usable by the caller.
---
 src/include/utils/injection_point.h      | 16 +++++++++
 src/backend/utils/misc/injection_point.c | 46 ++++++++++++++++++++++++
 src/tools/pgindent/typedefs.list         |  1 +
 3 files changed, 63 insertions(+)

diff --git a/src/include/utils/injection_point.h b/src/include/utils/injection_point.h
index a37958e1835f..fd5bc061b7bd 100644
--- a/src/include/utils/injection_point.h
+++ b/src/include/utils/injection_point.h
@@ -11,6 +11,19 @@
 #ifndef INJECTION_POINT_H
 #define INJECTION_POINT_H
 
+#include "nodes/pg_list.h"
+
+/*
+ * Injection point data, used when retrieving a list of all the attached
+ * injection points.
+ */
+typedef struct InjectionPointData
+{
+	const char *name;
+	const char *library;
+	const char *function;
+} InjectionPointData;
+
 /*
  * Injection points require --enable-injection-points.
  */
@@ -47,6 +60,9 @@ extern void InjectionPointCached(const char *name, void *arg);
 extern bool IsInjectionPointAttached(const char *name);
 extern bool InjectionPointDetach(const char *name);
 
+/* Get the current set of injection points attached */
+extern List *InjectionPointList(void);
+
 #ifdef EXEC_BACKEND
 extern PGDLLIMPORT struct InjectionPointsCtl *ActiveInjectionPoints;
 #endif
diff --git a/src/backend/utils/misc/injection_point.c b/src/backend/utils/misc/injection_point.c
index f58ebc8ee522..12570fba56e4 100644
--- a/src/backend/utils/misc/injection_point.c
+++ b/src/backend/utils/misc/injection_point.c
@@ -584,3 +584,49 @@ IsInjectionPointAttached(const char *name)
 	return false;				/* silence compiler */
 #endif
 }
+
+/*
+ * Retrieve a list of all the injection points currently attached.
+ *
+ * This list is palloc'd in the current memory context.
+ */
+List *
+InjectionPointList(void)
+{
+#ifdef USE_INJECTION_POINTS
+	List	   *inj_points = NIL;
+	uint32		max_inuse;
+
+	LWLockAcquire(InjectionPointLock, LW_SHARED);
+
+	max_inuse = pg_atomic_read_u32(&ActiveInjectionPoints->max_inuse);
+
+	for (uint32 idx = 0; idx < max_inuse; idx++)
+	{
+		InjectionPointEntry *entry;
+		InjectionPointData *inj_point;
+		uint64		generation;
+
+		entry = &ActiveInjectionPoints->entries[idx];
+		generation = pg_atomic_read_u64(&entry->generation);
+
+		/* skip free slots */
+		if (generation % 2 == 0)
+			continue;
+
+		inj_point = (InjectionPointData *) palloc0(sizeof(InjectionPointData));
+		inj_point->name = pstrdup(entry->name);
+		inj_point->library = pstrdup(entry->library);
+		inj_point->function = pstrdup(entry->function);
+		inj_points = lappend(inj_points, inj_point);
+	}
+
+	LWLockRelease(InjectionPointLock);
+
+	return inj_points;
+
+#else
+	elog(ERROR, "Injection points are not supported by this build");
+	return NIL;	/* keep compiler quiet */
+#endif
+}
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9ea573fae210..e4842de815e7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1283,6 +1283,7 @@ InjectionPointCacheEntry
 InjectionPointCallback
 InjectionPointCondition
 InjectionPointConditionType
+InjectionPointData
 InjectionPointEntry
 InjectionPointsCtl
 InjectionPointSharedState
-- 
2.49.0