Add wait event type "InjectionPoint", a custom type like "Extension".

Both injection points and customization of type "Extension" are new in
v17, so this just changes a detail of an unreleased feature.

Reported by Robert Haas.  Reviewed by Michael Paquier.

Discussion: https://postgr.es/m/CA+TgmobfMU5pdXP36D5iAwxV5WKE_vuDLtp_1QyH+H5jMMt21g@mail.gmail.com

5 files changed, 175 insertions, 108 deletions

diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 521ed5418cc..2100150f01c 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -149,7 +149,7 @@ CalculateShmemSize(int *num_semaphores)
 	size = add_size(size, SyncScanShmemSize());
 	size = add_size(size, AsyncShmemSize());
 	size = add_size(size, StatsShmemSize());
-	size = add_size(size, WaitEventExtensionShmemSize());
+	size = add_size(size, WaitEventCustomShmemSize());
 	size = add_size(size, InjectionPointShmemSize());
 	size = add_size(size, SlotSyncShmemSize());
 #ifdef EXEC_BACKEND
@@ -355,7 +355,7 @@ CreateOrAttachShmemStructs(void)
 	SyncScanShmemInit();
 	AsyncShmemInit();
 	StatsShmemInit();
-	WaitEventExtensionShmemInit();
+	WaitEventCustomShmemInit();
 	InjectionPointShmemInit();
 }
 
diff --git a/src/backend/utils/activity/generate-wait_event_types.pl b/src/backend/utils/activity/generate-wait_event_types.pl
index 42f36f405bd..6a9c0a5d347 100644
--- a/src/backend/utils/activity/generate-wait_event_types.pl
+++ b/src/backend/utils/activity/generate-wait_event_types.pl
@@ -181,9 +181,10 @@ if ($gen_code)
 	foreach my $waitclass (sort { uc($a) cmp uc($b) } keys %hashwe)
 	{
 		# Don't generate the pgstat_wait_event.c and wait_event_types.h files
-		# for Extension, LWLock and Lock, these are handled independently.
+		# for types handled independently.
 		next
 		  if ( $waitclass eq 'WaitEventExtension'
+			|| $waitclass eq 'WaitEventInjectionPoint'
 			|| $waitclass eq 'WaitEventLWLock'
 			|| $waitclass eq 'WaitEventLock');
 
diff --git a/src/backend/utils/activity/wait_event.c b/src/backend/utils/activity/wait_event.c
index 084a9dfdc28..bbf59482be1 100644
--- a/src/backend/utils/activity/wait_event.c
+++ b/src/backend/utils/activity/wait_event.c
@@ -47,68 +47,69 @@ uint32	   *my_wait_event_info = &local_my_wait_event_info;
  * Hash tables for storing custom wait event ids and their names in
  * shared memory.
  *
- * WaitEventExtensionHashById is used to find the name from an event id.
- * Any backend can search it to find custom wait events.
+ * WaitEventCustomHashByInfo is used to find the name from wait event
+ * information.  Any backend can search it to find custom wait events.
  *
- * WaitEventExtensionHashByName is used to find the event ID from a name.
- * It is used to ensure that no duplicated entries are registered.
+ * WaitEventCustomHashByName is used to find the wait event information from a
+ * name.  It is used to ensure that no duplicated entries are registered.
+ *
+ * For simplicity, we use the same ID counter across types of custom events.
+ * We could end that anytime the need arises.
  *
  * The size of the hash table is based on the assumption that
- * WAIT_EVENT_EXTENSION_HASH_INIT_SIZE is enough for most cases, and it seems
+ * WAIT_EVENT_CUSTOM_HASH_INIT_SIZE is enough for most cases, and it seems
  * unlikely that the number of entries will reach
- * WAIT_EVENT_EXTENSION_HASH_MAX_SIZE.
+ * WAIT_EVENT_CUSTOM_HASH_MAX_SIZE.
  */
-static HTAB *WaitEventExtensionHashById;	/* find names from IDs */
-static HTAB *WaitEventExtensionHashByName;	/* find IDs from names */
+static HTAB *WaitEventCustomHashByInfo; /* find names from infos */
+static HTAB *WaitEventCustomHashByName; /* find infos from names */
 
-#define WAIT_EVENT_EXTENSION_HASH_INIT_SIZE	16
-#define WAIT_EVENT_EXTENSION_HASH_MAX_SIZE	128
+#define WAIT_EVENT_CUSTOM_HASH_INIT_SIZE	16
+#define WAIT_EVENT_CUSTOM_HASH_MAX_SIZE	128
 
 /* hash table entries */
-typedef struct WaitEventExtensionEntryById
+typedef struct WaitEventCustomEntryByInfo
 {
-	uint16		event_id;		/* hash key */
+	uint32		wait_event_info;	/* hash key */
 	char		wait_event_name[NAMEDATALEN];	/* custom wait event name */
-} WaitEventExtensionEntryById;
+} WaitEventCustomEntryByInfo;
 
-typedef struct WaitEventExtensionEntryByName
+typedef struct WaitEventCustomEntryByName
 {
 	char		wait_event_name[NAMEDATALEN];	/* hash key */
-	uint16		event_id;		/* wait event ID */
-} WaitEventExtensionEntryByName;
+	uint32		wait_event_info;
+} WaitEventCustomEntryByName;
 
 
-/* dynamic allocation counter for custom wait events in extensions */
-typedef struct WaitEventExtensionCounterData
+/* dynamic allocation counter for custom wait events */
+typedef struct WaitEventCustomCounterData
 {
 	int			nextId;			/* next ID to assign */
 	slock_t		mutex;			/* protects the counter */
-} WaitEventExtensionCounterData;
+} WaitEventCustomCounterData;
 
 /* pointer to the shared memory */
-static WaitEventExtensionCounterData *WaitEventExtensionCounter;
-
-/* first event ID of custom wait events for extensions */
-#define WAIT_EVENT_EXTENSION_INITIAL_ID	1
+static WaitEventCustomCounterData *WaitEventCustomCounter;
 
-/* wait event info for extensions */
-#define WAIT_EVENT_EXTENSION_INFO(eventId)	(PG_WAIT_EXTENSION | eventId)
+/* first event ID of custom wait events */
+#define WAIT_EVENT_CUSTOM_INITIAL_ID	1
 
-static const char *GetWaitEventExtensionIdentifier(uint16 eventId);
+static uint32 WaitEventCustomNew(uint32 classId, const char *wait_event_name);
+static const char *GetWaitEventCustomIdentifier(uint32 wait_event_info);
 
 /*
  *  Return the space for dynamic shared hash tables and dynamic allocation counter.
  */
 Size
-WaitEventExtensionShmemSize(void)
+WaitEventCustomShmemSize(void)
 {
 	Size		sz;
 
-	sz = MAXALIGN(sizeof(WaitEventExtensionCounterData));
-	sz = add_size(sz, hash_estimate_size(WAIT_EVENT_EXTENSION_HASH_MAX_SIZE,
-										 sizeof(WaitEventExtensionEntryById)));
-	sz = add_size(sz, hash_estimate_size(WAIT_EVENT_EXTENSION_HASH_MAX_SIZE,
-										 sizeof(WaitEventExtensionEntryByName)));
+	sz = MAXALIGN(sizeof(WaitEventCustomCounterData));
+	sz = add_size(sz, hash_estimate_size(WAIT_EVENT_CUSTOM_HASH_MAX_SIZE,
+										 sizeof(WaitEventCustomEntryByInfo)));
+	sz = add_size(sz, hash_estimate_size(WAIT_EVENT_CUSTOM_HASH_MAX_SIZE,
+										 sizeof(WaitEventCustomEntryByName)));
 	return sz;
 }
 
@@ -116,39 +117,41 @@ WaitEventExtensionShmemSize(void)
  * Allocate shmem space for dynamic shared hash and dynamic allocation counter.
  */
 void
-WaitEventExtensionShmemInit(void)
+WaitEventCustomShmemInit(void)
 {
 	bool		found;
 	HASHCTL		info;
 
-	WaitEventExtensionCounter = (WaitEventExtensionCounterData *)
-		ShmemInitStruct("WaitEventExtensionCounterData",
-						sizeof(WaitEventExtensionCounterData), &found);
+	WaitEventCustomCounter = (WaitEventCustomCounterData *)
+		ShmemInitStruct("WaitEventCustomCounterData",
+						sizeof(WaitEventCustomCounterData), &found);
 
 	if (!found)
 	{
 		/* initialize the allocation counter and its spinlock. */
-		WaitEventExtensionCounter->nextId = WAIT_EVENT_EXTENSION_INITIAL_ID;
-		SpinLockInit(&WaitEventExtensionCounter->mutex);
+		WaitEventCustomCounter->nextId = WAIT_EVENT_CUSTOM_INITIAL_ID;
+		SpinLockInit(&WaitEventCustomCounter->mutex);
 	}
 
 	/* initialize or attach the hash tables to store custom wait events */
-	info.keysize = sizeof(uint16);
-	info.entrysize = sizeof(WaitEventExtensionEntryById);
-	WaitEventExtensionHashById = ShmemInitHash("WaitEventExtension hash by id",
-											   WAIT_EVENT_EXTENSION_HASH_INIT_SIZE,
-											   WAIT_EVENT_EXTENSION_HASH_MAX_SIZE,
-											   &info,
-											   HASH_ELEM | HASH_BLOBS);
+	info.keysize = sizeof(uint32);
+	info.entrysize = sizeof(WaitEventCustomEntryByInfo);
+	WaitEventCustomHashByInfo =
+		ShmemInitHash("WaitEventCustom hash by wait event information",
+					  WAIT_EVENT_CUSTOM_HASH_INIT_SIZE,
+					  WAIT_EVENT_CUSTOM_HASH_MAX_SIZE,
+					  &info,
+					  HASH_ELEM | HASH_BLOBS);
 
 	/* key is a NULL-terminated string */
 	info.keysize = sizeof(char[NAMEDATALEN]);
-	info.entrysize = sizeof(WaitEventExtensionEntryByName);
-	WaitEventExtensionHashByName = ShmemInitHash("WaitEventExtension hash by name",
-												 WAIT_EVENT_EXTENSION_HASH_INIT_SIZE,
-												 WAIT_EVENT_EXTENSION_HASH_MAX_SIZE,
-												 &info,
-												 HASH_ELEM | HASH_STRINGS);
+	info.entrysize = sizeof(WaitEventCustomEntryByName);
+	WaitEventCustomHashByName =
+		ShmemInitHash("WaitEventCustom hash by name",
+					  WAIT_EVENT_CUSTOM_HASH_INIT_SIZE,
+					  WAIT_EVENT_CUSTOM_HASH_MAX_SIZE,
+					  &info,
+					  HASH_ELEM | HASH_STRINGS);
 }
 
 /*
@@ -160,10 +163,23 @@ WaitEventExtensionShmemInit(void)
 uint32
 WaitEventExtensionNew(const char *wait_event_name)
 {
+	return WaitEventCustomNew(PG_WAIT_EXTENSION, wait_event_name);
+}
+
+uint32
+WaitEventInjectionPointNew(const char *wait_event_name)
+{
+	return WaitEventCustomNew(PG_WAIT_INJECTIONPOINT, wait_event_name);
+}
+
+static uint32
+WaitEventCustomNew(uint32 classId, const char *wait_event_name)
+{
 	uint16		eventId;
 	bool		found;
-	WaitEventExtensionEntryByName *entry_by_name;
-	WaitEventExtensionEntryById *entry_by_id;
+	WaitEventCustomEntryByName *entry_by_name;
+	WaitEventCustomEntryByInfo *entry_by_info;
+	uint32		wait_event_info;
 
 	/* Check the limit of the length of the event name */
 	if (strlen(wait_event_name) >= NAMEDATALEN)
@@ -175,13 +191,24 @@ WaitEventExtensionNew(const char *wait_event_name)
 	 * Check if the wait event info associated to the name is already defined,
 	 * and return it if so.
 	 */
-	LWLockAcquire(WaitEventExtensionLock, LW_SHARED);
-	entry_by_name = (WaitEventExtensionEntryByName *)
-		hash_search(WaitEventExtensionHashByName, wait_event_name,
+	LWLockAcquire(WaitEventCustomLock, LW_SHARED);
+	entry_by_name = (WaitEventCustomEntryByName *)
+		hash_search(WaitEventCustomHashByName, wait_event_name,
 					HASH_FIND, &found);
-	LWLockRelease(WaitEventExtensionLock);
+	LWLockRelease(WaitEventCustomLock);
 	if (found)
-		return WAIT_EVENT_EXTENSION_INFO(entry_by_name->event_id);
+	{
+		uint32		oldClassId;
+
+		oldClassId = entry_by_name->wait_event_info & WAIT_EVENT_CLASS_MASK;
+		if (oldClassId != classId)
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("wait event \"%s\" already exists in type \"%s\"",
+							wait_event_name,
+							pgstat_get_wait_event_type(entry_by_name->wait_event_info))));
+		return entry_by_name->wait_event_info;
+	}
 
 	/*
 	 * Allocate and register a new wait event.  Recheck if the event name
@@ -189,113 +216,123 @@ WaitEventExtensionNew(const char *wait_event_name)
 	 * one with the same name since the LWLock acquired again here was
 	 * previously released.
 	 */
-	LWLockAcquire(WaitEventExtensionLock, LW_EXCLUSIVE);
-	entry_by_name = (WaitEventExtensionEntryByName *)
-		hash_search(WaitEventExtensionHashByName, wait_event_name,
+	LWLockAcquire(WaitEventCustomLock, LW_EXCLUSIVE);
+	entry_by_name = (WaitEventCustomEntryByName *)
+		hash_search(WaitEventCustomHashByName, wait_event_name,
 					HASH_FIND, &found);
 	if (found)
 	{
-		LWLockRelease(WaitEventExtensionLock);
-		return WAIT_EVENT_EXTENSION_INFO(entry_by_name->event_id);
+		uint32		oldClassId;
+
+		LWLockRelease(WaitEventCustomLock);
+		oldClassId = entry_by_name->wait_event_info & WAIT_EVENT_CLASS_MASK;
+		if (oldClassId != classId)
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("wait event \"%s\" already exists in type \"%s\"",
+							wait_event_name,
+							pgstat_get_wait_event_type(entry_by_name->wait_event_info))));
+		return entry_by_name->wait_event_info;
 	}
 
 	/* Allocate a new event Id */
-	SpinLockAcquire(&WaitEventExtensionCounter->mutex);
+	SpinLockAcquire(&WaitEventCustomCounter->mutex);
 
-	if (WaitEventExtensionCounter->nextId >= WAIT_EVENT_EXTENSION_HASH_MAX_SIZE)
+	if (WaitEventCustomCounter->nextId >= WAIT_EVENT_CUSTOM_HASH_MAX_SIZE)
 	{
-		SpinLockRelease(&WaitEventExtensionCounter->mutex);
+		SpinLockRelease(&WaitEventCustomCounter->mutex);
 		ereport(ERROR,
 				errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
-				errmsg("too many wait events for extensions"));
+				errmsg("too many custom wait events"));
 	}
 
-	eventId = WaitEventExtensionCounter->nextId++;
+	eventId = WaitEventCustomCounter->nextId++;
 
-	SpinLockRelease(&WaitEventExtensionCounter->mutex);
+	SpinLockRelease(&WaitEventCustomCounter->mutex);
 
 	/* Register the new wait event */
-	entry_by_id = (WaitEventExtensionEntryById *)
-		hash_search(WaitEventExtensionHashById, &eventId,
+	wait_event_info = classId | eventId;
+	entry_by_info = (WaitEventCustomEntryByInfo *)
+		hash_search(WaitEventCustomHashByInfo, &wait_event_info,
 					HASH_ENTER, &found);
 	Assert(!found);
-	strlcpy(entry_by_id->wait_event_name, wait_event_name,
-			sizeof(entry_by_id->wait_event_name));
+	strlcpy(entry_by_info->wait_event_name, wait_event_name,
+			sizeof(entry_by_info->wait_event_name));
 
-	entry_by_name = (WaitEventExtensionEntryByName *)
-		hash_search(WaitEventExtensionHashByName, wait_event_name,
+	entry_by_name = (WaitEventCustomEntryByName *)
+		hash_search(WaitEventCustomHashByName, wait_event_name,
 					HASH_ENTER, &found);
 	Assert(!found);
-	entry_by_name->event_id = eventId;
+	entry_by_name->wait_event_info = wait_event_info;
 
-	LWLockRelease(WaitEventExtensionLock);
+	LWLockRelease(WaitEventCustomLock);
 
-	return WAIT_EVENT_EXTENSION_INFO(eventId);
+	return wait_event_info;
 }
 
 /*
- * Return the name of an wait event ID for extension.
+ * Return the name of a custom wait event information.
  */
 static const char *
-GetWaitEventExtensionIdentifier(uint16 eventId)
+GetWaitEventCustomIdentifier(uint32 wait_event_info)
 {
 	bool		found;
-	WaitEventExtensionEntryById *entry;
+	WaitEventCustomEntryByInfo *entry;
 
 	/* Built-in event? */
-	if (eventId < WAIT_EVENT_EXTENSION_INITIAL_ID)
+	if (wait_event_info == PG_WAIT_EXTENSION)
 		return "Extension";
 
 	/* It is a user-defined wait event, so lookup hash table. */
-	LWLockAcquire(WaitEventExtensionLock, LW_SHARED);
-	entry = (WaitEventExtensionEntryById *)
-		hash_search(WaitEventExtensionHashById, &eventId,
+	LWLockAcquire(WaitEventCustomLock, LW_SHARED);
+	entry = (WaitEventCustomEntryByInfo *)
+		hash_search(WaitEventCustomHashByInfo, &wait_event_info,
 					HASH_FIND, &found);
-	LWLockRelease(WaitEventExtensionLock);
+	LWLockRelease(WaitEventCustomLock);
 
 	if (!entry)
-		elog(ERROR, "could not find custom wait event name for ID %u",
-			 eventId);
+		elog(ERROR,
+			 "could not find custom name for wait event information %u",
+			 wait_event_info);
 
 	return entry->wait_event_name;
 }
 
 
 /*
- * Returns a list of currently defined custom wait event names for extensions.
- * The result is a palloc'd array, with the number of elements saved in
- * *nwaitevents.
+ * Returns a list of currently defined custom wait event names.  The result is
+ * a palloc'd array, with the number of elements saved in *nwaitevents.
  */
 char	  **
-GetWaitEventExtensionNames(int *nwaitevents)
+GetWaitEventCustomNames(uint32 classId, int *nwaitevents)
 {
 	char	  **waiteventnames;
-	WaitEventExtensionEntryByName *hentry;
+	WaitEventCustomEntryByName *hentry;
 	HASH_SEQ_STATUS hash_seq;
 	int			index;
 	int			els;
 
-	LWLockAcquire(WaitEventExtensionLock, LW_SHARED);
+	LWLockAcquire(WaitEventCustomLock, LW_SHARED);
 
 	/* Now we can safely count the number of entries */
-	els = hash_get_num_entries(WaitEventExtensionHashByName);
+	els = hash_get_num_entries(WaitEventCustomHashByName);
 
 	/* Allocate enough space for all entries */
 	waiteventnames = palloc(els * sizeof(char *));
 
 	/* Now scan the hash table to copy the data */
-	hash_seq_init(&hash_seq, WaitEventExtensionHashByName);
+	hash_seq_init(&hash_seq, WaitEventCustomHashByName);
 
 	index = 0;
-	while ((hentry = (WaitEventExtensionEntryByName *) hash_seq_search(&hash_seq)) != NULL)
+	while ((hentry = (WaitEventCustomEntryByName *) hash_seq_search(&hash_seq)) != NULL)
 	{
+		if ((hentry->wait_event_info & WAIT_EVENT_CLASS_MASK) != classId)
+			continue;
 		waiteventnames[index] = pstrdup(hentry->wait_event_name);
 		index++;
 	}
 
-	LWLockRelease(WaitEventExtensionLock);
-
-	Assert(index == els);
+	LWLockRelease(WaitEventCustomLock);
 
 	*nwaitevents = index;
 	return waiteventnames;
@@ -374,6 +411,9 @@ pgstat_get_wait_event_type(uint32 wait_event_info)
 		case PG_WAIT_IO:
 			event_type = "IO";
 			break;
+		case PG_WAIT_INJECTIONPOINT:
+			event_type = "InjectionPoint";
+			break;
 		default:
 			event_type = "???";
 			break;
@@ -411,7 +451,8 @@ pgstat_get_wait_event(uint32 wait_event_info)
 			event_name = GetLockNameFromTagType(eventId);
 			break;
 		case PG_WAIT_EXTENSION:
-			event_name = GetWaitEventExtensionIdentifier(eventId);
+		case PG_WAIT_INJECTIONPOINT:
+			event_name = GetWaitEventCustomIdentifier(wait_event_info);
 			break;
 		case PG_WAIT_BUFFERPIN:
 			{
diff --git a/src/backend/utils/activity/wait_event_funcs.c b/src/backend/utils/activity/wait_event_funcs.c
index ba244c2cf36..fa8bc05c0c7 100644
--- a/src/backend/utils/activity/wait_event_funcs.c
+++ b/src/backend/utils/activity/wait_event_funcs.c
@@ -48,7 +48,7 @@ pg_get_wait_events(PG_FUNCTION_ARGS)
 #define PG_GET_WAIT_EVENTS_COLS 3
 	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 	char	  **waiteventnames;
-	int			nbextwaitevents;
+	int			nbwaitevents;
 
 	/* Build tuplestore to hold the result rows */
 	InitMaterializedSRF(fcinfo, 0);
@@ -67,9 +67,10 @@ pg_get_wait_events(PG_FUNCTION_ARGS)
 	}
 
 	/* Handle custom wait events for extensions */
-	waiteventnames = GetWaitEventExtensionNames(&nbextwaitevents);
+	waiteventnames = GetWaitEventCustomNames(PG_WAIT_EXTENSION,
+											 &nbwaitevents);
 
-	for (int idx = 0; idx < nbextwaitevents; idx++)
+	for (int idx = 0; idx < nbwaitevents; idx++)
 	{
 		StringInfoData buf;
 		Datum		values[PG_GET_WAIT_EVENTS_COLS] = {0};
@@ -89,5 +90,29 @@ pg_get_wait_events(PG_FUNCTION_ARGS)
 		tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
 	}
 
+	/* Likewise for injection points */
+	waiteventnames = GetWaitEventCustomNames(PG_WAIT_INJECTIONPOINT,
+											 &nbwaitevents);
+
+	for (int idx = 0; idx < nbwaitevents; idx++)
+	{
+		StringInfoData buf;
+		Datum		values[PG_GET_WAIT_EVENTS_COLS] = {0};
+		bool		nulls[PG_GET_WAIT_EVENTS_COLS] = {0};
+
+
+		values[0] = CStringGetTextDatum("InjectionPoint");
+		values[1] = CStringGetTextDatum(waiteventnames[idx]);
+
+		initStringInfo(&buf);
+		appendStringInfo(&buf,
+						 "Waiting for injection point \"%s\"",
+						 waiteventnames[idx]);
+
+		values[2] = CStringGetTextDatum(buf.data);
+
+		tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+	}
+
 	return (Datum) 0;
 }
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index 87cbca28118..db37beeaae6 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -340,7 +340,7 @@ LogicalRepWorker	"Waiting to read or update the state of logical replication wor
 XactTruncation	"Waiting to execute <function>pg_xact_status</function> or update the oldest transaction ID available to it."
 WrapLimitsVacuum	"Waiting to update limits on transaction id and multixact consumption."
 NotifyQueueTail	"Waiting to update limit on <command>NOTIFY</command> message storage."
-WaitEventExtension	"Waiting to read or update custom wait events information for extensions."
+WaitEventCustom	"Waiting to read or update custom wait events information."
 WALSummarizer	"Waiting to read or update WAL summarization state."
 DSMRegistry	"Waiting to read or update the dynamic shared memory registry."
 InjectionPoint	"Waiting to read or update information related to injection points."