SET TRANSACTION ISOLATION LEVEL ...

LOCK TABLE IN ... MODE
...implemented

Author: vadim4o

src/backend/access/transam/varsup.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.17 1998/09/01 04:27:18 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.18 1998/12/18 09:10:17 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -311,6 +311,42 @@ GetNewTransactionId(TransactionId *xid)
 	SpinRelease(OidGenLockId);
 }
 
+/*
+ * Like GetNewTransactionId reads nextXid but don't fetch it.
+ */
+void
+ReadNewTransactionId(TransactionId *xid)
+{
+
+	/* ----------------
+	 *	during bootstrap initialization, we return the special
+	 *	bootstrap transaction id.
+	 * ----------------
+	 */
+	if (AMI_OVERRIDE)
+	{
+		TransactionIdStore(AmiTransactionId, xid);
+		return;
+	}
+
+	SpinAcquire(OidGenLockId);	/* not good for concurrency... */
+
+	if (ShmemVariableCache->xid_count == 0)
+	{
+		TransactionId nextid;
+
+		VariableRelationGetNextXid(&nextid);
+		TransactionIdStore(nextid, &(ShmemVariableCache->nextXid));
+		ShmemVariableCache->xid_count = VAR_XID_PREFETCH;
+		TransactionIdAdd(&nextid, VAR_XID_PREFETCH);
+		VariableRelationPutNextXid(nextid);
+	}
+
+	TransactionIdStore(ShmemVariableCache->nextXid, xid);
+
+	SpinRelease(OidGenLockId);
+}
+
 /* ----------------------------------------------------------------
  *					object id generation support
  * ----------------------------------------------------------------

src/backend/access/transam/xact.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.27 1998/12/16 11:53:44 vadim Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.28 1998/12/18 09:10:18 vadim Exp $
  *
  * NOTES
  *		Transaction aborts can now occur two ways:
@@ -194,7 +194,8 @@ TransactionStateData CurrentTransactionStateData = {
 TransactionState CurrentTransactionState =
 &CurrentTransactionStateData;
 
-int	XactIsoLevel = XACT_SERIALIZED;
+int	DefaultXactIsoLevel = XACT_SERIALIZABLE;
+int	XactIsoLevel;
 
 /* ----------------
  *		info returned when the system is disabled
@@ -798,6 +799,7 @@ StartTransaction()
 
 	TransactionIdFlushCache();
 	FreeXactSnapshot();
+	XactIsoLevel = DefaultXactIsoLevel;
 
 	/* ----------------
 	 *	Check the current transaction state.  If the transaction system

src/backend/commands/command.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.34 1998/12/15 12:45:52 vadim Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.35 1998/12/18 09:10:18 vadim Exp $
  *
  * NOTES
  *	  The PortalExecutorHeapMemory crap needs to be eliminated
@@ -39,6 +39,7 @@
 #include "utils/mcxt.h"
 #include "utils/portal.h"
 #include "utils/syscache.h"
+#include "miscadmin.h"
 
 /* ----------------
  *		PortalExecutorHeapMemory stuff
@@ -492,3 +493,25 @@ PerformAddAttribute(char *relationName,
 	pfree(reltup);
 	heap_close(rel);
 }
+
+void
+LockTableCommand(LockStmt *lockstmt)
+{
+	Relation	rel;
+	int			aclresult;
+
+	rel = heap_openr(lockstmt->relname);
+	if (rel == NULL)
+		elog(ERROR, "LOCK TABLE: relation %s can't be openned", lockstmt->relname);
+
+	if (lockstmt->mode == AccessShareLock)
+		aclresult = pg_aclcheck(lockstmt->relname, GetPgUserName(), ACL_RD);
+	else
+		aclresult = pg_aclcheck(lockstmt->relname, GetPgUserName(), ACL_WR);
+
+	if (aclresult != ACLCHECK_OK)
+		elog(ERROR, "LOCK TABLE: permission denied");
+
+	LockRelation(rel, lockstmt->mode);
+
+}

src/backend/commands/trigger.c

@@ -818,8 +818,8 @@ GetTupleForTrigger(EState *estate, ItemPointer tid, bool before)
 
 			case HeapTupleUpdated:
 				ReleaseBuffer(buffer);
-				if (XactIsoLevel == XACT_SERIALIZED)
-					elog(ERROR, "Serialize access failed due to concurrent update");
+				if (XactIsoLevel == XACT_SERIALIZABLE)
+					elog(ERROR, "Can't serialize access due to concurrent update");
 				else
 					elog(ERROR, "Isolation level %u is not supported", XactIsoLevel);
 				return(NULL);

src/backend/commands/variable.c

@@ -2,7 +2,7 @@
  * Routines for handling of 'SET var TO',
  *	'SHOW var' and 'RESET var' statements.
  *
- * $Id: variable.c,v 1.17 1998/10/26 00:59:22 tgl Exp $
+ * $Id: variable.c,v 1.18 1998/12/18 09:10:20 vadim Exp $
  *
  */
 
@@ -15,6 +15,7 @@
 #include "commands/variable.h"
 #include "utils/builtins.h"
 #include "optimizer/internal.h"
+#include "access/xact.h"
 #ifdef MULTIBYTE
 #include "mb/pg_wchar.h"
 #endif
@@ -44,6 +45,9 @@ static bool parse_geqo(const char *);
 static bool show_ksqo(void);
 static bool reset_ksqo(void);
 static bool parse_ksqo(const char *);
+static bool show_XactIsoLevel(void);
+static bool reset_XactIsoLevel(void);
+static bool parse_XactIsoLevel(const char *);
 #ifdef QUERY_LIMIT
 static bool show_query_limit(void);
 static bool reset_query_limit(void);
@@ -669,6 +673,9 @@ struct VariableParsers
 	{
 		"ksqo", parse_ksqo, show_ksqo, reset_ksqo
 	},
+	{
+		"XactIsoLevel", parse_XactIsoLevel, show_XactIsoLevel, reset_XactIsoLevel
+	},
 #ifdef QUERY_LIMIT
 	{
 		"query_limit", parse_query_limit, show_query_limit, reset_query_limit
@@ -773,3 +780,58 @@ reset_ksqo()
 	_use_keyset_query_optimizer = false;
 	return TRUE;
 }
+
+/* SET TRANSACTION */
+
+static bool
+parse_XactIsoLevel(const char *value)
+{
+	
+	if (value == NULL)
+	{
+		reset_XactIsoLevel();
+		return TRUE;
+	}
+
+	if (SerializableSnapshot != NULL)
+	{
+		elog(ERROR, "SET TRANSACTION ISOLATION LEVEL must be called before any query");
+		return TRUE;
+	}
+
+
+	if (strcasecmp(value, "SERIALIZABLE") == 0)
+		XactIsoLevel = XACT_SERIALIZABLE;
+	else if (strcasecmp(value, "COMMITTED") == 0)
+		XactIsoLevel = XACT_READ_COMMITTED;
+	else
+		elog(ERROR, "Bad TRANSACTION ISOLATION LEVEL (%s)", value);
+
+	return TRUE;
+}
+
+static bool
+show_XactIsoLevel()
+{
+
+	if (XactIsoLevel == XACT_SERIALIZABLE)
+		elog(NOTICE, "TRANSACTION ISOLATION LEVEL is SERIALIZABLE");
+	else
+		elog(NOTICE, "TRANSACTION ISOLATION LEVEL is READ COMMITTED");
+	return TRUE;
+}
+
+static bool
+reset_XactIsoLevel()
+{
+	
+	if (SerializableSnapshot != NULL)
+	{
+		elog(ERROR, "SET TRANSACTION ISOLATION LEVEL must be called before any query");
+		return TRUE;
+	}
+
+	XactIsoLevel = DefaultXactIsoLevel;
+
+	return TRUE;
+}

src/backend/executor/execMain.c

@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.61 1998/12/16 11:53:45 vadim Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.62 1998/12/18 09:10:21 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1037,8 +1037,8 @@ ExecDelete(TupleTableSlot *slot,
 			break;
 
 		case HeapTupleUpdated:
-			if (XactIsoLevel == XACT_SERIALIZED)
-				elog(ERROR, "Serialize access failed due to concurrent update");
+			if (XactIsoLevel == XACT_SERIALIZABLE)
+				elog(ERROR, "Can't serialize access due to concurrent update");
 			else
 				elog(ERROR, "Isolation level %u is not supported", XactIsoLevel);
 			return;
@@ -1167,8 +1167,8 @@ ExecReplace(TupleTableSlot *slot,
 			break;
 
 		case HeapTupleUpdated:
-			if (XactIsoLevel == XACT_SERIALIZED)
-				elog(ERROR, "Serialize access failed due to concurrent update");
+			if (XactIsoLevel == XACT_SERIALIZABLE)
+				elog(ERROR, "Can't serialize access due to concurrent update");
 			else
 				elog(ERROR, "Isolation level %u is not supported", XactIsoLevel);
 			return;