4 files changed, 54 insertions, 24 deletions

diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index cbf84ef7d8f..ddca78d3717 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -759,6 +759,7 @@ pg_wal_replay_wait(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	target_lsn = PG_GETARG_LSN(0);
 	int64		timeout = PG_GETARG_INT64(1);
+	WaitLSNResult result;
 
 	if (timeout < 0)
 		ereport(ERROR,
@@ -799,7 +800,35 @@ pg_wal_replay_wait(PG_FUNCTION_ARGS)
 	 */
 	Assert(MyProc->xmin == InvalidTransactionId);
 
-	(void) WaitForLSNReplay(target_lsn, timeout);
+	result = WaitForLSNReplay(target_lsn, timeout);
+
+	/*
+	 * Process the result of WaitForLSNReplay().  Throw appropriate error if
+	 * needed.
+	 */
+	switch (result)
+	{
+		case WAIT_LSN_RESULT_SUCCESS:
+			/* Nothing to do on success */
+			break;
+
+		case WAIT_LSN_RESULT_TIMEOUT:
+			ereport(ERROR,
+					(errcode(ERRCODE_QUERY_CANCELED),
+					 errmsg("timed out while waiting for target LSN %X/%X to be replayed; current replay LSN %X/%X",
+							LSN_FORMAT_ARGS(target_lsn),
+							LSN_FORMAT_ARGS(GetXLogReplayRecPtr(NULL)))));
+			break;
+
+		case WAIT_LSN_RESULT_NOT_IN_RECOVERY:
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("recovery is not in progress"),
+					 errdetail("Recovery ended before replaying target LSN %X/%X; last replay LSN %X/%X.",
+							   LSN_FORMAT_ARGS(target_lsn),
+							   LSN_FORMAT_ARGS(GetXLogReplayRecPtr(NULL)))));
+			break;
+	}
 
 	PG_RETURN_VOID();
 }
diff --git a/src/backend/access/transam/xlogwait.c b/src/backend/access/transam/xlogwait.c
index 353b7854dc8..58fb10aa5a8 100644
--- a/src/backend/access/transam/xlogwait.c
+++ b/src/backend/access/transam/xlogwait.c
@@ -217,7 +217,7 @@ WaitLSNCleanup(void)
  * Wait using MyLatch till the given LSN is replayed, the postmaster dies or
  * timeout happens.
  */
-void
+WaitLSNResult
 WaitForLSNReplay(XLogRecPtr targetLSN, int64 timeout)
 {
 	XLogRecPtr	currentLSN;
@@ -240,17 +240,14 @@ WaitForLSNReplay(XLogRecPtr targetLSN, int64 timeout)
 		 * check the last replay LSN before reporting an error.
 		 */
 		if (targetLSN <= GetXLogReplayRecPtr(NULL))
-			return;
-		ereport(ERROR,
-				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-				 errmsg("recovery is not in progress"),
-				 errhint("Waiting for LSN can only be executed during recovery.")));
+			return WAIT_LSN_RESULT_SUCCESS;
+		return WAIT_LSN_RESULT_NOT_IN_RECOVERY;
 	}
 	else
 	{
 		/* If target LSN is already replayed, exit immediately */
 		if (targetLSN <= GetXLogReplayRecPtr(NULL))
-			return;
+			return WAIT_LSN_RESULT_SUCCESS;
 	}
 
 	if (timeout > 0)
@@ -276,17 +273,13 @@ WaitForLSNReplay(XLogRecPtr targetLSN, int64 timeout)
 		{
 			/*
 			 * Recovery was ended, but recheck if target LSN was already
-			 * replayed.
+			 * replayed.  See the comment regarding deleteLSNWaiter() below.
 			 */
+			deleteLSNWaiter();
 			currentLSN = GetXLogReplayRecPtr(NULL);
 			if (targetLSN <= currentLSN)
-				return;
-			ereport(ERROR,
-					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-					 errmsg("recovery is not in progress"),
-					 errdetail("Recovery ended before replaying target LSN %X/%X; last replay LSN %X/%X.",
-							   LSN_FORMAT_ARGS(targetLSN),
-							   LSN_FORMAT_ARGS(currentLSN))));
+				return WAIT_LSN_RESULT_SUCCESS;
+			return WAIT_LSN_RESULT_NOT_IN_RECOVERY;
 		}
 		else
 		{
@@ -338,11 +331,7 @@ WaitForLSNReplay(XLogRecPtr targetLSN, int64 timeout)
 	 * If we didn't reach the target LSN, we must be exited by timeout.
 	 */
 	if (targetLSN > currentLSN)
-	{
-		ereport(ERROR,
-				(errcode(ERRCODE_QUERY_CANCELED),
-				 errmsg("timed out while waiting for target LSN %X/%X to be replayed; current replay LSN %X/%X",
-						LSN_FORMAT_ARGS(targetLSN),
-						LSN_FORMAT_ARGS(currentLSN))));
-	}
+		return WAIT_LSN_RESULT_TIMEOUT;
+
+	return WAIT_LSN_RESULT_SUCCESS;
 }
diff --git a/src/include/access/xlogwait.h b/src/include/access/xlogwait.h
index 31e208cb7ad..eb2260aa2ec 100644
--- a/src/include/access/xlogwait.h
+++ b/src/include/access/xlogwait.h
@@ -70,12 +70,23 @@ typedef struct WaitLSNState
 	WaitLSNProcInfo procInfos[FLEXIBLE_ARRAY_MEMBER];
 } WaitLSNState;
 
+/*
+ * Result statuses for WaitForLSNReplay().
+ */
+typedef enum
+{
+	WAIT_LSN_RESULT_SUCCESS,	/* Target LSN is reached */
+	WAIT_LSN_RESULT_TIMEOUT,	/* Timeout occurred */
+	WAIT_LSN_RESULT_NOT_IN_RECOVERY,	/* Recovery ended before or during our
+										 * wait */
+} WaitLSNResult;
+
 extern PGDLLIMPORT WaitLSNState *waitLSNState;
 
 extern Size WaitLSNShmemSize(void);
 extern void WaitLSNShmemInit(void);
 extern void WaitLSNSetLatches(XLogRecPtr currentLSN);
 extern void WaitLSNCleanup(void);
-extern void WaitForLSNReplay(XLogRecPtr targetLSN, int64 timeout);
+extern WaitLSNResult WaitForLSNReplay(XLogRecPtr targetLSN, int64 timeout);
 
 #endif							/* XLOG_WAIT_H */
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 4b8139c4b47..110089695e1 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3126,6 +3126,7 @@ WaitEventIPC
 WaitEventSet
 WaitEventTimeout
 WaitLSNProcInfo
+WaitLSNResult
 WaitLSNState
 WaitPMResult
 WalCloseMethod