changes_amit_2.patch

diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index df67851ac0..75119183da 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -1882,7 +1882,6 @@ apply_handle_stream_abort(StringInfo s)
 					pa_unlock_stream(xid, AccessExclusiveLock);
 					(void) pa_free_worker(winfo);
 				}
-
 				break;
 			}
 
@@ -1927,8 +1926,8 @@ apply_handle_stream_abort(StringInfo s)
 			 * We need to wait after processing rollback to savepoint for the
 			 * next set of changes.
 			 *
-			 * We have a race condition here when we can start waiting here
-			 * when there are more chunk of streams in the queue. See
+			 * We have a race condition here due to which we can start waiting
+			 * here when there are more chunk of streams in the queue. See
 			 * apply_handle_stream_stop.
 			 */
 			if (!toplevel_xact)
@@ -4242,8 +4241,8 @@ stream_write_change(char action, StringInfo s)
  *	  Serialize a message to a file for the given transaction.
  *
  * This function is similar to stream_write_change except that it will open the
- * target file if not already before writing the message and close file at the
- * end.
+ * target file if not already before writing the message and close the file at
+ * the end.
  */
 static void
 stream_open_and_write_change(TransactionId xid, char action, StringInfo s)
@@ -4926,10 +4925,9 @@ set_apply_error_context_origin(char *originname)
 }
 
 /*
- * Return the action to take for the given transaction. *winfo is assigned to
- * the destination parallel worker info (if the action is
- * TRANS_LEADER_SEND_TO_PARALLEL or TRANS_LEADER_PARTIAL_SERIALIZE), otherwise
- * *winfo is assigned NULL.
+ * Return the action to be taken for the given transaction. *winfo is
+ * assigned to the destination parallel worker info when the given
+ * transaction is being processed using a parallel apply worker.
  */
 static TransApplyAction
 get_transaction_apply_action(TransactionId xid, ParallelApplyWorkerInfo **winfo)
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index a362688fde..1a75686b79 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -58,10 +58,12 @@ typedef struct LogicalRepWorker
 
 	/*
 	 * Used to create the changes and subxact files for the streaming
-	 * transactions.  Upon the arrival of the first streaming transaction, the
-	 * fileset will be initialized, and it will be deleted when the worker
-	 * exits.  Under this, separate buffiles would be created for each
-	 * transaction which will be deleted after the transaction is finished.
+	 * transactions.  Upon the arrival of the first streaming transaction or
+	 * when the first-time leader apply worker times out while sending changes
+	 * to the parallel apply worker, the fileset will be initialized, and it
+	 * will be deleted when the worker exits.  Under this, separate buffiles
+	 * would be created for each transaction which will be deleted after the
+	 * transaction is finished.
 	 */
 	FileSet    *stream_fileset;
 
@@ -96,12 +98,20 @@ typedef enum ParallelTransState
 } ParallelTransState;
 
 /*
- * State of fileset in leader apply worker.
+ * State of fileset used to communicate changes from leader to parallel
+ * apply worker.
  *
- * FS_SERIALIZE_IN_PROGRESS means that the leader is serializing changes to the
- * file. FS_SERIALIZE_DONE means that the leader has serialized all changes to
- * the file. FS_READY means that it is now ok for a parallel apply worker read
+ * FS_EMPTY indicates an initial state where the leader doesn't need to use
+ * the file to communicate with the parallel apply worker.
+ *
+ * FS_SERIALIZE_IN_PROGRESS indicates that the leader is serializing changes
+ * to the file.
+ *
+ * FS_SERIALIZE_DONE indicates that the leader has serialized all changes to
  * the file.
+ *
+ * FS_READY indicates that it is now ok for a parallel apply worker to
+ * read the file.
  */
 typedef enum PartialFileSetState
 {