code: replace most remaining uses of 'master'.

Author: Andres Freund
Reviewed-By: David Steele
Discussion: https://postgr.es/m/20200615182235.x7lch5n6kcjq4aue@alap3.anarazel.de

src/backend/access/transam/xlog.c

@@ -562,11 +562,12 @@ typedef struct XLogCtlInsert
 	char		pad[PG_CACHE_LINE_SIZE];
 
 	/*
-	 * fullPageWrites is the master copy used by all backends to determine
-	 * whether to write full-page to WAL, instead of using process-local one.
-	 * This is required because, when full_page_writes is changed by SIGHUP,
-	 * we must WAL-log it before it actually affects WAL-logging by backends.
-	 * Checkpointer sets at startup or after SIGHUP.
+	 * fullPageWrites is the authoritative value used by all backends to
+	 * determine whether to write full-page image to WAL. This shared value,
+	 * instead of the process-local fullPageWrites, is required because, when
+	 * full_page_writes is changed by SIGHUP, we must WAL-log it before it
+	 * actually affects WAL-logging by backends.  Checkpointer sets at startup
+	 * or after SIGHUP.
 	 *
 	 * To read these fields, you must hold an insertion lock. To modify them,
 	 * you must hold ALL the locks.
@@ -8366,8 +8367,9 @@ GetRedoRecPtr(void)
 
 	/*
 	 * The possibly not up-to-date copy in XlogCtl is enough. Even if we
-	 * grabbed a WAL insertion lock to read the master copy, someone might
-	 * update it just after we've released the lock.
+	 * grabbed a WAL insertion lock to read the authoritative value in
+	 * Insert->RedoRecPtr, someone might update it just after we've released
+	 * the lock.
 	 */
 	SpinLockAcquire(&XLogCtl->info_lck);
 	ptr = XLogCtl->RedoRecPtr;

src/backend/catalog/index.c

@@ -3765,7 +3765,7 @@ reindex_relation(Oid relid, int flags, int options)
 
 	/*
 	 * If the relation has a secondary toast rel, reindex that too while we
-	 * still hold the lock on the master table.
+	 * still hold the lock on the main table.
 	 */
 	if ((flags & REINDEX_REL_PROCESS_TOAST) && OidIsValid(toast_relid))
 		result |= reindex_relation(toast_relid, flags, options);

src/backend/catalog/toasting.c

@@ -345,8 +345,8 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
 	table_close(class_rel, RowExclusiveLock);
 
 	/*
-	 * Register dependency from the toast table to the master, so that the
-	 * toast table will be deleted if the master is.  Skip this in bootstrap
+	 * Register dependency from the toast table to the main, so that the
+	 * toast table will be deleted if the main is.  Skip this in bootstrap
 	 * mode.
 	 */
 	if (!IsBootstrapProcessingMode())

src/backend/commands/vacuum.c

@@ -1897,7 +1897,7 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 
 	/*
 	 * If the relation has a secondary toast rel, vacuum that too while we
-	 * still hold the session lock on the master table.  Note however that
+	 * still hold the session lock on the main table.  Note however that
 	 * "analyze" will not get done on the toast table.  This is good, because
 	 * the toaster always uses hardcoded index access and statistics are
 	 * totally unimportant for toast relations.
@@ -1906,7 +1906,7 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 		vacuum_rel(toast_relid, NULL, params);
 
 	/*
-	 * Now release the session-level lock on the master table.
+	 * Now release the session-level lock on the main table.
 	 */
 	UnlockRelationIdForSession(&onerelid, lmode);
 

src/backend/libpq/hba.c

@@ -145,7 +145,7 @@ static List *tokenize_inc_file(List *tokens, const char *outer_filename,
 static bool parse_hba_auth_opt(char *name, char *val, HbaLine *hbaline,
 							   int elevel, char **err_msg);
 static bool verify_option_list_length(List *options, const char *optionname,
-									  List *masters, const char *mastername, int line_num);
+									  List *comparelist, const char *comparename, int line_num);
 static ArrayType *gethba_options(HbaLine *hba);
 static void fill_hba_line(Tuplestorestate *tuple_store, TupleDesc tupdesc,
 						  int lineno, HbaLine *hba, const char *err_msg);
@@ -1648,11 +1648,13 @@ parse_hba_line(TokenizedLine *tok_line, int elevel)
 
 
 static bool
-verify_option_list_length(List *options, const char *optionname, List *masters, const char *mastername, int line_num)
+verify_option_list_length(List *options, const char *optionname,
+						  List *comparelist, const char *comparename,
+						  int line_num)
 {
 	if (list_length(options) == 0 ||
 		list_length(options) == 1 ||
-		list_length(options) == list_length(masters))
+		list_length(options) == list_length(comparelist))
 		return true;
 
 	ereport(LOG,
@@ -1660,8 +1662,8 @@ verify_option_list_length(List *options, const char *optionname, List *masters,
 			 errmsg("the number of %s (%d) must be 1 or the same as the number of %s (%d)",
 					optionname,
 					list_length(options),
-					mastername,
-					list_length(masters)
+					comparename,
+					list_length(comparelist)
 					),
 			 errcontext("line %d of configuration file \"%s\"",
 						line_num, HbaFileName)));

src/backend/libpq/pqcomm.c

@@ -705,8 +705,8 @@ Setup_AF_UNIX(const char *sock_path)
  *		server port.  Set port->sock to the FD of the new connection.
  *
  * ASSUME: that this doesn't need to be non-blocking because
- *		the Postmaster uses select() to tell when the server master
- *		socket is ready for accept().
+ *		the Postmaster uses select() to tell when the socket is ready for
+ *		accept().
  *
  * RETURNS: STATUS_OK or STATUS_ERROR
  */

src/backend/optimizer/plan/planner.c

@@ -1748,7 +1748,7 @@ inheritance_planner(PlannerInfo *root)
 	else
 	{
 		/*
-		 * Put back the final adjusted rtable into the master copy of the
+		 * Put back the final adjusted rtable into the original copy of the
 		 * Query.  (We mustn't do this if we found no non-excluded children,
 		 * since we never saved an adjusted rtable at all.)
 		 */
@@ -1757,7 +1757,7 @@ inheritance_planner(PlannerInfo *root)
 		root->simple_rel_array = save_rel_array;
 		root->append_rel_array = save_append_rel_array;
 
-		/* Must reconstruct master's simple_rte_array, too */
+		/* Must reconstruct original's simple_rte_array, too */
 		root->simple_rte_array = (RangeTblEntry **)
 			palloc0((list_length(final_rtable) + 1) * sizeof(RangeTblEntry *));
 		rti = 1;

src/backend/parser/gram.y

@@ -15016,7 +15016,7 @@ ColLabel:	IDENT									{ $$ = $1; }
  *
  * Make sure that each keyword's category in kwlist.h matches where
  * it is listed here.  (Someday we may be able to generate these lists and
- * kwlist.h's table from a common master list.)
+ * kwlist.h's table from one source of truth.)
  */
 
 /* "Unreserved" keywords --- available for use as any kind of name.

src/backend/snowball/README

@@ -22,8 +22,8 @@ At least on Linux, no platform-specific adjustment is needed.
 Postgres' files under src/backend/snowball/libstemmer/ and
 src/include/snowball/libstemmer/ are taken directly from the Snowball
 files, with only some minor adjustments of file inclusions.  Note
-that most of these files are in fact derived files, not master source.
-The master sources are in the Snowball language, and are built using
+that most of these files are in fact derived files, not original source.
+The original sources are in the Snowball language, and are built using
 the Snowball-to-C compiler that is also part of the Snowball project.
 We choose to include the derived files in the PostgreSQL distribution
 because most installations will not have the Snowball compiler available.

src/backend/utils/time/snapmgr.c

@@ -2222,9 +2222,9 @@ RestoreSnapshot(char *start_address)
  * the declaration for PGPROC.
  */
 void
-RestoreTransactionSnapshot(Snapshot snapshot, void *master_pgproc)
+RestoreTransactionSnapshot(Snapshot snapshot, void *source_pgproc)
 {
-	SetTransactionSnapshot(snapshot, NULL, InvalidPid, master_pgproc);
+	SetTransactionSnapshot(snapshot, NULL, InvalidPid, source_pgproc);
 }
 
 /*

src/include/nodes/execnodes.h

@@ -496,7 +496,7 @@ typedef struct ResultRelInfo
 /* ----------------
  *	  EState information
  *
- * Master working state for an Executor invocation
+ * Working state for an Executor invocation
  * ----------------
  */
 typedef struct EState

src/include/utils/snapmgr.h

@@ -153,6 +153,6 @@ extern bool HistoricSnapshotActive(void);
 extern Size EstimateSnapshotSpace(Snapshot snapshot);
 extern void SerializeSnapshot(Snapshot snapshot, char *start_address);
 extern Snapshot RestoreSnapshot(char *start_address);
-extern void RestoreTransactionSnapshot(Snapshot snapshot, void *master_pgproc);
+extern void RestoreTransactionSnapshot(Snapshot snapshot, void *source_pgproc);
 
 #endif							/* SNAPMGR_H */

src/pl/tcl/pltcl.c

@@ -432,9 +432,9 @@ _PG_init(void)
 	 * stdout and stderr on DeleteInterp
 	 ************************************************************/
 	if ((pltcl_hold_interp = Tcl_CreateInterp()) == NULL)
-		elog(ERROR, "could not create master Tcl interpreter");
+		elog(ERROR, "could not create dummy Tcl interpreter");
 	if (Tcl_Init(pltcl_hold_interp) == TCL_ERROR)
-		elog(ERROR, "could not initialize master Tcl interpreter");
+		elog(ERROR, "could not initialize dummy Tcl interpreter");
 
 	/************************************************************
 	 * Create the hash table for working interpreters
@@ -489,14 +489,14 @@ pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
 	char		interpname[32];
 
 	/************************************************************
-	 * Create the Tcl interpreter as a slave of pltcl_hold_interp.
+	 * Create the Tcl interpreter subsidiary to pltcl_hold_interp.
 	 * Note: Tcl automatically does Tcl_Init in the untrusted case,
 	 * and it's not wanted in the trusted case.
 	 ************************************************************/
-	snprintf(interpname, sizeof(interpname), "slave_%u", interp_desc->user_id);
+	snprintf(interpname, sizeof(interpname), "subsidiary_%u", interp_desc->user_id);
 	if ((interp = Tcl_CreateSlave(pltcl_hold_interp, interpname,
 								  pltrusted ? 1 : 0)) == NULL)
-		elog(ERROR, "could not create slave Tcl interpreter");
+		elog(ERROR, "could not create subsidiary Tcl interpreter");
 
 	/************************************************************
 	 * Initialize the query hash table associated with interpreter