5 files changed, 44 insertions, 0 deletions
diff --git a/src/include/commands/wait.h b/src/include/commands/wait.h
new file mode 100644
index 00000000000..2a95c95d2b7
--- /dev/null
+++ b/src/include/commands/wait.h
@@ -0,0 +1,26 @@
+/*-------------------------------------------------------------------------
+ *
+ * wait.h
+ *	  prototypes for commands/wait.c
+ *
+ * Copyright (c) 2020, PostgreSQL Global Development Group
+ *
+ * src/include/commands/wait.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef WAIT_H
+#define WAIT_H
+
+#include "tcop/dest.h"
+#include "nodes/parsenodes.h"
+
+extern bool WaitLSNUtility(XLogRecPtr lsn, const int timeout_ms);
+extern Size WaitLSNShmemSize(void);
+extern void WaitLSNShmemInit(void);
+extern void WaitLSNSetLatch(XLogRecPtr cur_lsn);
+extern XLogRecPtr WaitLSNGetMin(void);
+extern int	WaitLSNMain(WaitClause *stmt, DestReceiver *dest);
+extern void WaitLSNDelete(void);
+
+#endif							/* WAIT_H */
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 381d84b4e4f..822827aa32d 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -492,6 +492,7 @@ typedef enum NodeTag
 	T_StartReplicationCmd,
 	T_TimeLineHistoryCmd,
 	T_SQLCmd,
+	T_WaitClause,
 
 	/*
 	 * TAGS FOR RANDOM OTHER STUFF
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 518abe42c10..7ad3ddbf579 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1432,6 +1432,17 @@ typedef struct OnConflictClause
 } OnConflictClause;
 
 /*
+ * WaitClause -
+ *		representation of WAIT FOR clause for BEGIN and START TRANSACTION.
+ */
+typedef struct WaitClause
+{
+	NodeTag		type;
+	char	   *lsn;			/* LSN to wait for */
+	int			timeout;		/* Number of milliseconds to limit wait time */
+} WaitClause;
+
+/*
  * CommonTableExpr -
  *	   representation of WITH list element
  *
@@ -3060,6 +3071,7 @@ typedef struct TransactionStmt
 	char	   *savepoint_name; /* for savepoint commands */
 	char	   *gid;			/* for two-phase-commit related commands */
 	bool		chain;			/* AND CHAIN option */
+	Node	   *wait;			/* WAIT FOR clause */
 } TransactionStmt;
 
 /* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 08f22ce211d..6e1848fe4cc 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -243,6 +243,7 @@ PG_KEYWORD("location", LOCATION, UNRESERVED_KEYWORD)
 PG_KEYWORD("lock", LOCK_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("locked", LOCKED, UNRESERVED_KEYWORD)
 PG_KEYWORD("logged", LOGGED, UNRESERVED_KEYWORD)
+PG_KEYWORD("lsn", LSN, UNRESERVED_KEYWORD)
 PG_KEYWORD("mapping", MAPPING, UNRESERVED_KEYWORD)
 PG_KEYWORD("match", MATCH, UNRESERVED_KEYWORD)
 PG_KEYWORD("materialized", MATERIALIZED, UNRESERVED_KEYWORD)
@@ -410,6 +411,7 @@ PG_KEYWORD("text", TEXT_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("then", THEN, RESERVED_KEYWORD)
 PG_KEYWORD("ties", TIES, UNRESERVED_KEYWORD)
 PG_KEYWORD("time", TIME, COL_NAME_KEYWORD)
+PG_KEYWORD("timeout", TIMEOUT, UNRESERVED_KEYWORD)
 PG_KEYWORD("timestamp", TIMESTAMP, COL_NAME_KEYWORD)
 PG_KEYWORD("to", TO, RESERVED_KEYWORD)
 PG_KEYWORD("trailing", TRAILING, RESERVED_KEYWORD)
@@ -450,6 +452,7 @@ PG_KEYWORD("version", VERSION_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("view", VIEW, UNRESERVED_KEYWORD)
 PG_KEYWORD("views", VIEWS, UNRESERVED_KEYWORD)
 PG_KEYWORD("volatile", VOLATILE, UNRESERVED_KEYWORD)
+PG_KEYWORD("wait", WAIT, UNRESERVED_KEYWORD)
 PG_KEYWORD("when", WHEN, RESERVED_KEYWORD)
 PG_KEYWORD("where", WHERE, RESERVED_KEYWORD)
 PG_KEYWORD("whitespace", WHITESPACE_P, UNRESERVED_KEYWORD)
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index 03a1de569f0..eaeeb79c411 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -109,4 +109,6 @@ extern int	date2isoyearday(int year, int mon, int mday);
 
 extern bool TimestampTimestampTzRequiresRewrite(void);
 
+#define GetNowFloat() ((float8) GetCurrentTimestamp() / 1000000.0)
+
 #endif							/* TIMESTAMP_H */