5 files changed, 22 insertions, 6 deletions
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index 3ba23f5e87b..503ae1b82d7 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -60,7 +60,9 @@ typedef enum
 	SYNCHRONOUS_COMMIT_LOCAL_FLUSH,		/* wait for local flush only */
 	SYNCHRONOUS_COMMIT_REMOTE_WRITE,	/* wait for local flush and remote
 										 * write */
-	SYNCHRONOUS_COMMIT_REMOTE_FLUSH		/* wait for local and remote flush */
+	SYNCHRONOUS_COMMIT_REMOTE_FLUSH,	/* wait for local and remote flush */
+	SYNCHRONOUS_COMMIT_REMOTE_APPLY		/* wait for local flush and remote
+										 * apply */
 }	SyncCommitLevel;
 
 /* Define the default setting for synchonous_commit */
@@ -144,10 +146,13 @@ typedef void (*SubXactCallback) (SubXactEvent event, SubTransactionId mySubid,
  * EOXact... routines which run at the end of the original transaction
  * completion.
  */
+#define XACT_COMPLETION_APPLY_FEEDBACK			(1U << 29)
 #define XACT_COMPLETION_UPDATE_RELCACHE_FILE	(1U << 30)
 #define XACT_COMPLETION_FORCE_SYNC_COMMIT		(1U << 31)
 
 /* Access macros for above flags */
+#define XactCompletionApplyFeedback(xinfo) \
+	((xinfo & XACT_COMPLETION_APPLY_FEEDBACK) != 0)
 #define XactCompletionRelcacheInitFileInval(xinfo) \
 	((xinfo & XACT_COMPLETION_UPDATE_RELCACHE_FILE) != 0)
 #define XactCompletionForceSyncCommit(xinfo) \
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 74a139496e6..a7dcdae67f8 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -267,6 +267,8 @@ extern bool CheckPromoteSignal(void);
 extern void WakeupRecovery(void);
 extern void SetWalWriterSleeping(bool sleeping);
 
+extern void XLogRequestWalReceiverReply(void);
+
 extern void assign_max_wal_size(int newval, void *extra);
 extern void assign_checkpoint_completion_target(double newval, void *extra);
 
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index e8b64dd4262..aa2f074201a 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -31,7 +31,7 @@
 /*
  * Each page of XLOG file has a header like this:
  */
-#define XLOG_PAGE_MAGIC 0xD088	/* can be used as WAL version indicator */
+#define XLOG_PAGE_MAGIC 0xD089	/* can be used as WAL version indicator */
 
 typedef struct XLogPageHeaderData
 {
diff --git a/src/include/replication/syncrep.h b/src/include/replication/syncrep.h
index 96e059bc3fa..c005a425836 100644
--- a/src/include/replication/syncrep.h
+++ b/src/include/replication/syncrep.h
@@ -23,8 +23,9 @@
 #define SYNC_REP_NO_WAIT		-1
 #define SYNC_REP_WAIT_WRITE		0
 #define SYNC_REP_WAIT_FLUSH		1
+#define SYNC_REP_WAIT_APPLY		2
 
-#define NUM_SYNC_REP_WAIT_MODE	2
+#define NUM_SYNC_REP_WAIT_MODE	3
 
 /* syncRepState */
 #define SYNC_REP_NOT_WAITING		0
@@ -35,7 +36,7 @@
 extern char *SyncRepStandbyNames;
 
 /* called by user backend */
-extern void SyncRepWaitForLSN(XLogRecPtr XactCommitLSN);
+extern void SyncRepWaitForLSN(XLogRecPtr lsn, bool commit);
 
 /* called at backend exit */
 extern void SyncRepCleanupAtProcExit(void);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 6eacb095d1b..36bcb471720 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -113,9 +113,16 @@ typedef struct
 	slock_t		mutex;			/* locks shared variables shown above */
 
 	/*
+	 * force walreceiver reply?  This doesn't need to be locked; memory
+	 * barriers for ordering are sufficient.
+	 */
+	bool		force_reply;
+
+	/*
 	 * Latch used by startup process to wake up walreceiver after telling it
 	 * where to start streaming (after setting receiveStart and
-	 * receiveStartTLI).
+	 * receiveStartTLI), and also to tell it to send apply feedback to the
+	 * primary whenever specially marked commit records are applied.
 	 */
 	Latch		latch;
 } WalRcvData;
@@ -138,7 +145,7 @@ extern PGDLLIMPORT walrcv_startstreaming_type walrcv_startstreaming;
 typedef void (*walrcv_endstreaming_type) (TimeLineID *next_tli);
 extern PGDLLIMPORT walrcv_endstreaming_type walrcv_endstreaming;
 
-typedef int (*walrcv_receive_type) (int timeout, char **buffer);
+typedef int (*walrcv_receive_type) (char **buffer, int *wait_fd);
 extern PGDLLIMPORT walrcv_receive_type walrcv_receive;
 
 typedef void (*walrcv_send_type) (const char *buffer, int nbytes);
@@ -162,5 +169,6 @@ extern void RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr,
 extern XLogRecPtr GetWalRcvWriteRecPtr(XLogRecPtr *latestChunkStart, TimeLineID *receiveTLI);
 extern int	GetReplicationApplyDelay(void);
 extern int	GetReplicationTransferLatency(void);
+extern void WalRcvForceReply(void);
 
 #endif   /* _WALRECEIVER_H */