Minor sync rep corrections.

Fujii Masao, with a bit of additional wordsmithing by me.

src/backend/replication/syncrep.c

@@ -447,9 +447,9 @@ SyncRepGetStandbyPriority(void)
 }
 
 /*
- * Walk queue from head setting setting the state of any backends that
- * need to be woken, remove them from the queue and then wake them.
- * Set all = true to wake whole queue, or just up to LSN.
+ * Walk queue from head.  Set the state of any backends that need to be woken,
+ * remove them from the queue, and then wake them.  Pass all = true to wake
+ * whole queue; otherwise, just wake up to the walsender's LSN.
  *
  * Must hold SyncRepLock.
  */

src/backend/storage/ipc/shmqueue.c

@@ -157,7 +157,7 @@ SHMQueueNext(const SHM_QUEUE *queue, const SHM_QUEUE *curElem, Size linkOffset)
 /*--------------------
  * SHMQueuePrev -- Get the previous element from a queue
  *
- * Same as SHMQueueNext, just starting at tail and moving towards head
+ * Same as SHMQueueNext, just starting at tail and moving towards head.
  * All other comments and usage applies.
  */
 Pointer

src/include/replication/syncrep.h

@@ -29,7 +29,6 @@
 
 /* user-settable parameters for synchronous replication */
 extern bool sync_rep_mode;
-extern int 	sync_rep_timeout;
 extern char *SyncRepStandbyNames;
 
 /* called by user backend */
@@ -44,6 +43,6 @@ extern void SyncRepReleaseWaiters(void);
 
 /* called by various procs */
 extern int SyncRepWakeQueue(bool all);
-const char *assign_synchronous_standby_names(const char *newval, bool doit, GucSource source);
+extern const char *assign_synchronous_standby_names(const char *newval, bool doit, GucSource source);
 
 #endif   /* _SYNCREP_H */