replace Begin words in coordinated transactions with use (#3293)

src/backend/distributed/commands/multi_copy.c

@@ -298,7 +298,7 @@ PG_FUNCTION_INFO_V1(citus_text_send_as_jsonb);
 static void
 CitusCopyFrom(CopyStmt *copyStatement, char *completionTag)
 {
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	/* disallow COPY to/from file or program except for superusers */
 	if (copyStatement->filename != NULL && !superuser())
@@ -2251,7 +2251,7 @@ CitusCopyDestReceiverStartup(DestReceiver *dest, int operation,
 	/* keep the table metadata to avoid looking it up for every tuple */
 	copyDest->tableMetadata = cacheEntry;
 
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	if (cacheEntry->replicationModel == REPLICATION_MODEL_2PC ||
 		MultiShardCommitProtocol == COMMIT_PROTOCOL_2PC)

src/backend/distributed/commands/truncate.c

@@ -237,7 +237,7 @@ AcquireDistributedLockOnRelations(List *relationIdList, LOCKMODE lockMode)
 	relationIdList = SortList(relationIdList, CompareOids);
 	workerNodeList = SortList(workerNodeList, CompareWorkerNodes);
 
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	foreach_oid(relationId, relationIdList)
 	{

src/backend/distributed/executor/adaptive_executor.c

@@ -897,7 +897,7 @@ StartDistributedExecution(DistributedExecution *execution)
 		 */
 		if (DistributedExecutionRequiresRollback(execution) || LocalExecutionHappened)
 		{
-			BeginOrContinueCoordinatedTransaction();
+			UseCoordinatedTransaction();
 
 			if (TaskListRequires2PC(taskList) || LocalExecutionHappened)
 			{

src/backend/distributed/executor/intermediate_results.c

@@ -122,7 +122,7 @@ broadcast_intermediate_result(PG_FUNCTION_ARGS)
 	 * Intermediate results will be stored in a directory that is derived
 	 * from the distributed transaction ID.
 	 */
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	List *nodeList = ActivePrimaryWorkerNodeList(NoLock);
 	EState *estate = CreateExecutorState();
@@ -164,7 +164,7 @@ create_intermediate_result(PG_FUNCTION_ARGS)
 	 * Intermediate results will be stored in a directory that is derived
 	 * from the distributed transaction ID.
 	 */
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	EState *estate = CreateExecutorState();
 	RemoteFileDestReceiver *resultDest =

src/backend/distributed/executor/subplan_execution.c

@@ -53,7 +53,7 @@ ExecuteSubPlans(DistributedPlan *distributedPlan)
 	 * Intermediate results of subplans will be stored in a directory that is
 	 * derived from the distributed transaction ID.
 	 */
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	foreach(subPlanCell, subPlanList)
 	{

src/backend/distributed/master/master_delete_protocol.c

@@ -361,7 +361,7 @@ DropShards(Oid relationId, char *schemaName, char *relationName,
 {
 	ListCell *shardIntervalCell = NULL;
 
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	/* At this point we intentionally decided to not use 2PC for reference tables */
 	if (MultiShardCommitProtocol == COMMIT_PROTOCOL_2PC)

src/backend/distributed/master/master_stage_protocol.c

@@ -284,7 +284,7 @@ master_append_table_to_shard(PG_FUNCTION_ARGS)
 						errhint("Try running master_create_empty_shard() first")));
 	}
 
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	/* issue command to append table to each shard placement */
 	foreach(shardPlacementCell, shardPlacementList)

src/backend/distributed/planner/multi_explain.c

@@ -386,7 +386,7 @@ RemoteExplain(Task *task, ExplainState *es)
 	 * Use a coordinated transaction to ensure that we open a transaction block
 	 * such that we can set a savepoint.
 	 */
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	for (int placementIndex = 0; placementIndex < placementCount; placementIndex++)
 	{

src/backend/distributed/transaction/backend_data.c

@@ -720,7 +720,7 @@ GetCurrentDistributedTransactionId(void)
  * sets it for the current backend. It also sets the databaseId and
  * processId fields.
  *
- * This function should only be called on BeginCoordinatedTransaction(). Any other
+ * This function should only be called on UseCoordinatedTransaction(). Any other
  * callers is very likely to break the distributed transaction management.
  */
 void

src/backend/distributed/transaction/transaction_management.c

@@ -96,7 +96,6 @@ bool FunctionOpensTransactionBlock = true;
 
 
 /* transaction management functions */
-static void BeginCoordinatedTransaction(void);
 static void CoordinatedTransactionCallback(XactEvent event, void *arg);
 static void CoordinatedSubTransactionCallback(SubXactEvent event, SubTransactionId subId,
 											  SubTransactionId parentSubid, void *arg);
@@ -111,18 +110,26 @@ static bool MaybeExecutingUDF(void);
 
 
 /*
- * BeginOrContinueCoordinatedTransaction starts a coordinated transaction,
- * unless one already is in progress.
+ * UseCoordinatedTransaction sets up the necessary variables to use
+ * a coordinated transaction, unless one is already in progress.
  */
 void
-BeginOrContinueCoordinatedTransaction(void)
+UseCoordinatedTransaction(void)
 {
 	if (CurrentCoordinatedTransactionState == COORD_TRANS_STARTED)
 	{
 		return;
 	}
 
-	BeginCoordinatedTransaction();
+	if (CurrentCoordinatedTransactionState != COORD_TRANS_NONE &&
+		CurrentCoordinatedTransactionState != COORD_TRANS_IDLE)
+	{
+		ereport(ERROR, (errmsg("starting transaction in wrong state")));
+	}
+
+	CurrentCoordinatedTransactionState = COORD_TRANS_STARTED;
+
+	AssignDistributedTransactionId();
 }
 
 
@@ -169,25 +176,6 @@ InitializeTransactionManagement(void)
 }
 
 
-/*
- * BeginCoordinatedTransaction begins a coordinated transaction. No
- * pre-existing coordinated transaction may be in progress./
- */
-static void
-BeginCoordinatedTransaction(void)
-{
-	if (CurrentCoordinatedTransactionState != COORD_TRANS_NONE &&
-		CurrentCoordinatedTransactionState != COORD_TRANS_IDLE)
-	{
-		ereport(ERROR, (errmsg("starting transaction in wrong state")));
-	}
-
-	CurrentCoordinatedTransactionState = COORD_TRANS_STARTED;
-
-	AssignDistributedTransactionId();
-}
-
-
 /*
  * Transaction management callback, handling coordinated transaction, and
  * transaction independent connection management.

src/backend/distributed/transaction/worker_transaction.c

@@ -89,7 +89,7 @@ SendCommandToWorkerAsUser(char *nodeName, int32 nodePort, const char *nodeUser,
 {
 	uint connectionFlags = 0;
 
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 	CoordinatedTransactionUse2PC();
 
 	MultiConnection *transactionConnection = GetNodeUserDatabaseConnection(
@@ -279,7 +279,7 @@ SendCommandToWorkersParamsInternal(TargetWorkerSet targetWorkerSet, const char *
 	List *workerNodeList = TargetWorkerSetNodeList(targetWorkerSet, ShareLock);
 	ListCell *workerNodeCell = NULL;
 
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 	CoordinatedTransactionUse2PC();
 
 	/* open connections in parallel */

src/backend/distributed/utils/resource_lock.c

@@ -197,7 +197,7 @@ LockShardListResourcesOnFirstWorker(LOCKMODE lockmode, List *shardIntervalList)
 	appendStringInfo(lockCommand, "])");
 
 	/* need to hold the lock until commit */
-	BeginOrContinueCoordinatedTransaction();
+	UseCoordinatedTransaction();
 
 	/*
 	 * Use the superuser connection to make sure we are allowed to lock.

src/include/distributed/transaction_management.h

@@ -106,7 +106,7 @@ extern StringInfo activeSetStmts;
 /*
  * Coordinated transaction management.
  */
-extern void BeginOrContinueCoordinatedTransaction(void);
+extern void UseCoordinatedTransaction(void);
 extern bool InCoordinatedTransaction(void);
 extern void CoordinatedTransactionUse2PC(void);
 extern bool IsMultiStatementTransaction(void);