From 0639ce8e14074fb8bc34a7135bc9cad9086800ec Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Sat, 21 Mar 2026 19:05:26 +0200
Subject: [PATCH v9 09/16] Convert injection points to use the new interface

---
 src/backend/storage/ipc/ipci.c           |  3 --
 src/backend/utils/misc/injection_point.c | 60 ++++++++++++------------
 src/include/storage/subsystemlist.h      |  2 +-
 src/include/utils/injection_point.h      |  3 --
 4 files changed, 30 insertions(+), 38 deletions(-)

diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 3d70cb76ad6..2ae4b9c2ac2 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -52,7 +52,6 @@
 #include "storage/sinvaladt.h"
 #include "storage/subsystems.h"
 #include "utils/guc.h"
-#include "utils/injection_point.h"
 #include "utils/wait_event.h"
 
 /* GUCs */
@@ -139,7 +138,6 @@ CalculateShmemSize(void)
 	size = add_size(size, AsyncShmemSize());
 	size = add_size(size, StatsShmemSize());
 	size = add_size(size, WaitEventCustomShmemSize());
-	size = add_size(size, InjectionPointShmemSize());
 	size = add_size(size, SlotSyncShmemSize());
 	size = add_size(size, AioShmemSize());
 	size = add_size(size, WaitLSNShmemSize());
@@ -353,7 +351,6 @@ CreateOrAttachShmemStructs(void)
 	AsyncShmemInit();
 	StatsShmemInit();
 	WaitEventCustomShmemInit();
-	InjectionPointShmemInit();
 	AioShmemInit();
 	WaitLSNShmemInit();
 	LogicalDecodingCtlShmemInit();
diff --git a/src/backend/utils/misc/injection_point.c b/src/backend/utils/misc/injection_point.c
index c06b0e9b800..9981d6e212f 100644
--- a/src/backend/utils/misc/injection_point.c
+++ b/src/backend/utils/misc/injection_point.c
@@ -17,6 +17,7 @@
  */
 #include "postgres.h"
 
+#include "storage/subsystems.h"
 #include "utils/injection_point.h"
 
 #ifdef USE_INJECTION_POINTS
@@ -109,6 +110,11 @@ typedef struct InjectionPointCacheEntry
 
 static HTAB *InjectionPointCache = NULL;
 
+#ifdef USE_INJECTION_POINTS
+static void InjectionPointShmemRequest(void *arg);
+static void InjectionPointShmemInit(void *arg);
+#endif
+
 /*
  * injection_point_cache_add
  *
@@ -226,46 +232,38 @@ injection_point_cache_get(const char *name)
 }
 #endif							/* USE_INJECTION_POINTS */
 
-/*
- * Return the space for dynamic shared hash table.
- */
-Size
-InjectionPointShmemSize(void)
-{
+const ShmemCallbacks InjectionPointShmemCallbacks = {
 #ifdef USE_INJECTION_POINTS
-	Size		sz = 0;
-
-	sz = add_size(sz, sizeof(InjectionPointsCtl));
-	return sz;
-#else
-	return 0;
+	.request_fn = InjectionPointShmemRequest,
+	.init_fn = InjectionPointShmemInit,
 #endif
-}
+};
 
 /*
- * Allocate shmem space for dynamic shared hash.
+ * Reserve space for the dynamic shared hash table
  */
-void
-InjectionPointShmemInit(void)
-{
 #ifdef USE_INJECTION_POINTS
-	bool		found;
+static void
+InjectionPointShmemRequest(void *arg)
+{
+	static ShmemStructDesc InjectionPointShmemDesc;
 
-	ActiveInjectionPoints = ShmemInitStruct("InjectionPoint hash",
-											sizeof(InjectionPointsCtl),
-											&found);
-	if (!IsUnderPostmaster)
-	{
-		Assert(!found);
-		pg_atomic_init_u32(&ActiveInjectionPoints->max_inuse, 0);
-		for (int i = 0; i < MAX_INJECTION_POINTS; i++)
-			pg_atomic_init_u64(&ActiveInjectionPoints->entries[i].generation, 0);
-	}
-	else
-		Assert(found);
-#endif
+	ShmemRequestStruct(&InjectionPointShmemDesc,
+					   .name = "InjectionPoint hash",
+					   .size = sizeof(InjectionPointsCtl),
+					   .ptr = (void **) &ActiveInjectionPoints,
+		);
 }
 
+static void
+InjectionPointShmemInit(void *arg)
+{
+	pg_atomic_init_u32(&ActiveInjectionPoints->max_inuse, 0);
+	for (int i = 0; i < MAX_INJECTION_POINTS; i++)
+		pg_atomic_init_u64(&ActiveInjectionPoints->entries[i].generation, 0);
+}
+#endif
+
 /*
  * Attach a new injection point.
  */
diff --git a/src/include/storage/subsystemlist.h b/src/include/storage/subsystemlist.h
index ed43c90bcc3..65da6f17c5d 100644
--- a/src/include/storage/subsystemlist.h
+++ b/src/include/storage/subsystemlist.h
@@ -20,4 +20,4 @@
  * of these matter.
  */
 
-/* TODO: empty for now */
+PG_SHMEM_SUBSYSTEM(InjectionPointShmemCallbacks)
diff --git a/src/include/utils/injection_point.h b/src/include/utils/injection_point.h
index 27a2526524f..fabd1455c3c 100644
--- a/src/include/utils/injection_point.h
+++ b/src/include/utils/injection_point.h
@@ -46,9 +46,6 @@ typedef void (*InjectionPointCallback) (const char *name,
 										const void *private_data,
 										void *arg);
 
-extern Size InjectionPointShmemSize(void);
-extern void InjectionPointShmemInit(void);
-
 extern void InjectionPointAttach(const char *name,
 								 const char *library,
 								 const char *function,
-- 
2.47.3