PG 15 Compat: Resolve compile issues + shmem requests

Similar to #5897, one more step for running Citus with PG 15.

This PR at least make Citus run with PG 15. I have not tried running the tests with PG 15.

Shmem changes are based on 4f2400cb3f

Compile breaks are mostly due to #6008

src/backend/distributed/commands/foreign_data_wrapper.c

@@ -83,7 +83,7 @@ PreprocessGrantOnFDWStmt(Node *node, const char *queryString,
 static bool
 NameListHasFDWOwnedByDistributedExtension(List *FDWNames)
 {
-	Value *FDWValue = NULL;
+	String *FDWValue = NULL;
 	foreach_ptr(FDWValue, FDWNames)
 	{
 		/* captures the extension address during lookup */

src/backend/distributed/commands/function.c

@@ -2038,7 +2038,7 @@ FilterDistributedFunctions(GrantStmt *grantStmt)
 		List *namespaceOidList = NIL;
 
 		/* iterate over all namespace names provided to get their oid's */
-		Value *namespaceValue = NULL;
+		String *namespaceValue = NULL;
 		foreach_ptr(namespaceValue, grantStmt->objects)
 		{
 			char *nspname = strVal(namespaceValue);

src/backend/distributed/commands/policy.c

@@ -612,8 +612,8 @@ RenamePolicyEventExtendNames(RenameStmt *stmt, const char *schemaName, uint64 sh
 void
 DropPolicyEventExtendNames(DropStmt *dropStmt, const char *schemaName, uint64 shardId)
 {
-	Value *relationSchemaNameValue = NULL;
-	Value *relationNameValue = NULL;
+	String *relationSchemaNameValue = NULL;
+	String *relationNameValue = NULL;
 
 	uint32 dropCount = list_length(dropStmt->objects);
 	if (dropCount > 1)
@@ -652,10 +652,10 @@ DropPolicyEventExtendNames(DropStmt *dropStmt, const char *schemaName, uint64 sh
 	/* prefix with schema name if it is not added already */
 	if (relationSchemaNameValue == NULL)
 	{
-		Value *schemaNameValue = makeString(pstrdup(schemaName));
+		String *schemaNameValue = makeString(pstrdup(schemaName));
 		relationNameList = lcons(schemaNameValue, relationNameList);
 	}
 
-	char **relationName = &(relationNameValue->val.str);
+	char **relationName = &(strVal(relationNameValue));
 	AppendShardIdToName(relationName, shardId);
 }

src/backend/distributed/commands/sequence.c

@@ -825,7 +825,7 @@ FilterDistributedSequences(GrantStmt *stmt)
 	{
 		/* iterate over all namespace names provided to get their oid's */
 		List *namespaceOidList = NIL;
-		Value *namespaceValue = NULL;
+		String *namespaceValue = NULL;
 		foreach_ptr(namespaceValue, stmt->objects)
 		{
 			char *nspname = strVal(namespaceValue);

src/backend/distributed/commands/subscription.c

@@ -103,7 +103,7 @@ GenerateConninfoWithAuth(char *conninfo)
 		}
 		else if (strcmp(option->keyword, "port") == 0)
 		{
-			port = pg_atoi(option->val, 4, 0);
+			port = pg_strtoint32(option->val);
 		}
 		else if (strcmp(option->keyword, "user") == 0)
 		{

src/backend/distributed/connection/connection_configuration.c

@@ -455,7 +455,7 @@ GetEffectiveConnKey(ConnectionHashKey *key)
 		}
 		else if (strcmp(option->keyword, "port") == 0)
 		{
-			effectiveKey->port = pg_atoi(option->val, 4, 0);
+			effectiveKey->port = pg_strtoint32(option->val);
 		}
 		else if (strcmp(option->keyword, "dbname") == 0)
 		{

src/backend/distributed/connection/shared_connection_stats.c

@@ -123,8 +123,6 @@ static void StoreAllRemoteConnectionStats(Tuplestorestate *tupleStore, TupleDesc
 										  tupleDescriptor);
 static void LockConnectionSharedMemory(LWLockMode lockMode);
 static void UnLockConnectionSharedMemory(void);
-static void SharedConnectionStatsShmemInit(void);
-static size_t SharedConnectionStatsShmemSize(void);
 static bool ShouldWaitForConnection(int currentConnectionCount);
 static uint32 SharedConnectionHashHash(const void *key, Size keysize);
 static int SharedConnectionHashCompare(const void *a, const void *b, Size keysize);
@@ -617,11 +615,15 @@ WaitForSharedConnection(void)
 void
 InitializeSharedConnectionStats(void)
 {
+/* on PG 15, we use shmem_request_hook_type */
+#if PG_VERSION_NUM < PG_VERSION_15
+
 	/* allocate shared memory */
 	if (!IsUnderPostmaster)
 	{
 		RequestAddinShmemSpace(SharedConnectionStatsShmemSize());
 	}
+#endif
 
 	prev_shmem_startup_hook = shmem_startup_hook;
 	shmem_startup_hook = SharedConnectionStatsShmemInit;
@@ -632,7 +634,7 @@ InitializeSharedConnectionStats(void)
  * SharedConnectionStatsShmemSize returns the size that should be allocated
  * on the shared memory for shared connection stats.
  */
-static size_t
+size_t
 SharedConnectionStatsShmemSize(void)
 {
 	Size size = 0;
@@ -652,7 +654,7 @@ SharedConnectionStatsShmemSize(void)
  * SharedConnectionStatsShmemInit initializes the shared memory used
  * for keeping track of connection stats across backends.
  */
-static void
+void
 SharedConnectionStatsShmemInit(void)
 {
 	bool alreadyInitialized = false;

src/backend/distributed/executor/query_stats.c

@@ -49,7 +49,6 @@
 #define STICKY_DECREASE_FACTOR (0.50)   /* factor for sticky entries */
 #define USAGE_DEALLOC_PERCENT 5         /* free this % of entries at once */
 #define USAGE_INIT (1.0)                /* including initial planning */
-#define STATS_SHARED_MEM_NAME "citus_query_stats"
 
 #define MAX_KEY_LENGTH NAMEDATALEN
 
@@ -124,7 +123,6 @@ PG_FUNCTION_INFO_V1(citus_executor_name);
 
 static char * CitusExecutorName(MultiExecutorType executorType);
 
-static Size CitusQueryStatsSharedMemSize(void);
 
 static void CitusQueryStatsShmemStartup(void);
 static void CitusQueryStatsShmemShutdown(int code, Datum arg);
@@ -142,11 +140,19 @@ static void CitusQueryStatsRemoveExpiredEntries(HTAB *existingQueryIdHash);
 
 void
 InitializeCitusQueryStats(void)
+{
+/* on PG 15, we use shmem_request_hook_type */
+#if PG_VERSION_NUM < PG_VERSION_15
+
+	/* allocate shared memory */
+	if (!IsUnderPostmaster)
 	{
 		RequestAddinShmemSpace(CitusQueryStatsSharedMemSize());
 
 		elog(LOG, "requesting named LWLockTranch for %s", STATS_SHARED_MEM_NAME);
 		RequestNamedLWLockTranche(STATS_SHARED_MEM_NAME, 1);
+	}
+#endif
 
 	/* Install hook */
 	prev_shmem_startup_hook = shmem_startup_hook;
@@ -373,7 +379,7 @@ error:
  * CitusQueryStatsSharedMemSize calculates and returns shared memory size
  * required to keep query statistics.
  */
-static Size
+Size
 CitusQueryStatsSharedMemSize(void)
 {
 	Assert(StatStatementsMax >= 0);
@@ -947,7 +953,7 @@ GetPGStatStatementsMax(void)
 	 */
 	if (pgssMax)
 	{
-		maxValue = pg_atoi(pgssMax, 4, 0);
+		maxValue = pg_strtoint32(pgssMax);
 	}
 
 	return maxValue;

src/backend/distributed/replication/multi_logical_replication.c

@@ -33,6 +33,7 @@
 #include "catalog/namespace.h"
 #include "catalog/pg_constraint.h"
 #include "distributed/adaptive_executor.h"
+#include "distributed/citus_safe_lib.h"
 #include "distributed/colocation_utils.h"
 #include "distributed/connection_management.h"
 #include "distributed/listutils.h"
@@ -1808,7 +1809,7 @@ TotalRelationSizeForSubscription(MultiConnection *connection, char *command)
 	{
 		char *resultString = PQgetvalue(result, 0, 0);
 
-		remoteTotalSize = pg_strtouint64(resultString, NULL, 10);
+		remoteTotalSize = SafeStringToUint64(resultString);
 	}
 	else
 	{

src/backend/distributed/shared_library_init.c

@@ -141,6 +141,7 @@ DEFINE_COLUMNAR_PASSTHROUGH_FUNC(test_columnar_storage_write_new_page)
 
 #define DUMMY_REAL_TIME_EXECUTOR_ENUM_VALUE 9999999
 static char *CitusVersion = CITUS_VERSION;
+static char *DeprecatedEmptyString = "";
 
 /* deprecated GUC value that should not be used anywhere outside this file */
 static int ReplicationModel = REPLICATION_MODEL_STREAMING;
@@ -150,8 +151,15 @@ static GucStringAssignHook OldApplicationNameAssignHook = NULL;
 
 static object_access_hook_type PrevObjectAccessHook = NULL;
 
+#if PG_VERSION_NUM >= PG_VERSION_15
+static shmem_request_hook_type prev_shmem_request_hook = NULL;
+#endif
+
 void _PG_init(void);
 
+#if PG_VERSION_NUM >= PG_VERSION_15
+static void citus_shmem_request(void);
+#endif
 static void CitusObjectAccessHook(ObjectAccessType access, Oid classId, Oid objectId, int
 								  subId, void *arg);
 static void DoInitialCleanup(void);
@@ -368,6 +376,11 @@ _PG_init(void)
 	original_client_auth_hook = ClientAuthentication_hook;
 	ClientAuthentication_hook = CitusAuthHook;
 
+#if PG_VERSION_NUM >= PG_VERSION_15
+	prev_shmem_request_hook = shmem_request_hook;
+	shmem_request_hook = citus_shmem_request;
+#endif
+
 	InitializeMaintenanceDaemon();
 
 	/* initialize coordinated transaction management */
@@ -400,6 +413,7 @@ _PG_init(void)
 	PrevObjectAccessHook = object_access_hook;
 	object_access_hook = CitusObjectAccessHook;
 
+
 	/* ensure columnar module is loaded at the right time */
 	load_file(COLUMNAR_MODULE_NAME, false);
 
@@ -442,6 +456,30 @@ _PG_init(void)
 }
 
 
+#if PG_VERSION_NUM >= PG_VERSION_15
+
+/*
+ * Requests any additional shared memory required for citus.
+ */
+static void
+citus_shmem_request(void)
+{
+	if (prev_shmem_request_hook)
+	{
+		prev_shmem_request_hook();
+	}
+
+	RequestAddinShmemSpace(BackendManagementShmemSize());
+	RequestAddinShmemSpace(SharedConnectionStatsShmemSize());
+	RequestAddinShmemSpace(MaintenanceDaemonShmemSize());
+	RequestAddinShmemSpace(CitusQueryStatsSharedMemSize());
+	RequestNamedLWLockTranche(STATS_SHARED_MEM_NAME, 1);
+}
+
+
+#endif
+
+
 /*
  * DoInitialCleanup does cleanup at start time.
  * Currently it:
@@ -1234,6 +1272,26 @@ RegisterCitusConfigVariables(void)
 		GUC_NO_SHOW_ALL,
 		NULL, NULL, NULL);
 
+	/*
+	 * This was a GUC we added on Citus 11.0.1, and
+	 * replaced with another name on 11.0.2 via #5920.
+	 * However, as this GUC has been used in
+	 * citus_shard_indexes_on_worker-11.0.1
+	 * script. So, it is not easy to completely get rid
+	 * of the GUC. Especially with PG 15+, Postgres verifies
+	 * existence of the GUCs that are used. So, without this
+	 * CREATE EXTENSION fails.
+	 */
+	DefineCustomStringVariable(
+		"citus.hide_shards_from_app_name_prefixes",
+		gettext_noop("Deprecated, use citus.show_shards_for_app_name_prefixes"),
+		NULL,
+		&DeprecatedEmptyString,
+		"",
+		PGC_SUSET,
+		GUC_NO_SHOW_ALL,
+		NULL, NULL, NULL);
+
 	DefineCustomIntVariable(
 		"citus.isolation_test_session_process_id",
 		NULL,

src/backend/distributed/transaction/backend_data.c

@@ -104,8 +104,6 @@ static BackendData *MyBackendData = NULL;
 static CitusBackendType CurrentBackendType = CITUS_BACKEND_NOT_ASSIGNED;
 
 
-static void BackendManagementShmemInit(void);
-static size_t BackendManagementShmemSize(void);
 static void DetermineCitusBackendType(void);
 
 
@@ -515,12 +513,15 @@ UserHasPermissionToViewStatsOf(Oid currentUserId, Oid backendOwnedId)
 void
 InitializeBackendManagement(void)
 {
+/* on PG 15, we use shmem_request_hook_type */
+#if PG_VERSION_NUM < PG_VERSION_15
+
 	/* allocate shared memory */
 	if (!IsUnderPostmaster)
 	{
 		RequestAddinShmemSpace(BackendManagementShmemSize());
 	}
-
+#endif
 	prev_shmem_startup_hook = shmem_startup_hook;
 	shmem_startup_hook = BackendManagementShmemInit;
 }
@@ -531,7 +532,7 @@ InitializeBackendManagement(void)
  * memory startup hook. The function sets up the necessary shared memory
  * segment for the backend manager.
  */
-static void
+void
 BackendManagementShmemInit(void)
 {
 	bool alreadyInitialized = false;
@@ -599,7 +600,7 @@ BackendManagementShmemInit(void)
  * BackendManagementShmemSize returns the size that should be allocated
  * on the shared memory for backend management.
  */
-static size_t
+size_t
 BackendManagementShmemSize(void)
 {
 	Size size = 0;

src/backend/distributed/utils/maintenanced.c

@@ -117,8 +117,6 @@ static bool IsMaintenanceDaemon = false;
 
 static void MaintenanceDaemonSigTermHandler(SIGNAL_ARGS);
 static void MaintenanceDaemonSigHupHandler(SIGNAL_ARGS);
-static size_t MaintenanceDaemonShmemSize(void);
-static void MaintenanceDaemonShmemInit(void);
 static void MaintenanceDaemonShmemExit(int code, Datum arg);
 static void MaintenanceDaemonErrorContext(void *arg);
 static bool MetadataSyncTriggeredCheckAndReset(MaintenanceDaemonDBData *dbData);
@@ -133,11 +131,6 @@ static void WarnMaintenanceDaemonNotStarted(void);
 void
 InitializeMaintenanceDaemon(void)
 {
-	if (!IsUnderPostmaster)
-	{
-		RequestAddinShmemSpace(MaintenanceDaemonShmemSize());
-	}
-
 	prev_shmem_startup_hook = shmem_startup_hook;
 	shmem_startup_hook = MaintenanceDaemonShmemInit;
 }
@@ -743,7 +736,7 @@ CitusMaintenanceDaemonMain(Datum main_arg)
 /*
  * MaintenanceDaemonShmemSize computes how much shared memory is required.
  */
-static size_t
+size_t
 MaintenanceDaemonShmemSize(void)
 {
 	Size size = 0;
@@ -767,7 +760,7 @@ MaintenanceDaemonShmemSize(void)
  * MaintenanceDaemonShmemInit initializes the requested shared memory for the
  * maintenance daemon.
  */
-static void
+void
 MaintenanceDaemonShmemInit(void)
 {
 	bool alreadyInitialized = false;

src/include/distributed/backend_data.h

@@ -45,6 +45,8 @@ typedef struct BackendData
 } BackendData;
 
 
+extern void BackendManagementShmemInit(void);
+extern size_t BackendManagementShmemSize(void);
 extern void InitializeBackendManagement(void);
 extern int TotalProcCount(void);
 extern void InitializeBackendData(void);

src/include/distributed/maintenanced.h

@@ -24,6 +24,8 @@ extern double DistributedDeadlockDetectionTimeoutFactor;
 extern void StopMaintenanceDaemon(Oid databaseId);
 extern void TriggerNodeMetadataSync(Oid databaseId);
 extern void InitializeMaintenanceDaemon(void);
+extern size_t MaintenanceDaemonShmemSize(void);
+extern void MaintenanceDaemonShmemInit(void);
 extern void InitializeMaintenanceDaemonBackend(void);
 extern bool LockCitusExtension(void);
 

src/include/distributed/query_stats.h

@@ -12,6 +12,9 @@
 
 #include "distributed/multi_server_executor.h"
 
+#define STATS_SHARED_MEM_NAME "citus_query_stats"
+
+extern Size CitusQueryStatsSharedMemSize(void);
 extern void InitializeCitusQueryStats(void);
 extern void CitusQueryStatsExecutorsEntry(uint64 queryId, MultiExecutorType executorType,
 										  char *partitionKey);

src/include/distributed/shared_connection_stats.h

@@ -25,6 +25,8 @@ extern int MaxClientConnections;
 extern void InitializeSharedConnectionStats(void);
 extern void WaitForSharedConnection(void);
 extern void WakeupWaiterBackendsForSharedConnection(void);
+extern size_t SharedConnectionStatsShmemSize(void);
+extern void SharedConnectionStatsShmemInit(void);
 extern int GetMaxClientConnections(void);
 extern int GetMaxSharedPoolSize(void);
 extern int GetLocalSharedPoolSize(void);