Refactor ps_status.c API

The init_ps_display() arguments were mostly lies by now, so to match
typical usage, just use one argument and let the caller assemble it
from multiple sources if necessary.  The only user of the additional
arguments is BackendInitialize(), which was already doing string
assembly on the caller side anyway.

Remove the second argument of set_ps_display() ("force") and just
handle that in init_ps_display() internally.

BackendInitialize() also used to set the initial status as
"authentication", but that was very far from where authentication
actually happened.  So now it's set to "initializing" and then
"authentication" just before the actual call to
ClientAuthentication().
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Kuntal Ghosh <kuntalghosh.2007@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/c65e5196-4f04-4ead-9353-6088c19615a3@2ndquadrant.com

src/backend/access/transam/xlog.c

@@ -3648,7 +3648,7 @@ XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli,
 			/* Report recovery progress in PS display */
 			snprintf(activitymsg, sizeof(activitymsg), "waiting for %s",
 					 xlogfname);
-			set_ps_display(activitymsg, false);
+			set_ps_display(activitymsg);
 
 			restoredFromArchive = RestoreArchivedFile(path, xlogfname,
 													  "RECOVERYXLOG",
@@ -3691,7 +3691,7 @@ XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli,
 		/* Report recovery progress in PS display */
 		snprintf(activitymsg, sizeof(activitymsg), "recovering %s",
 				 xlogfname);
-		set_ps_display(activitymsg, false);
+		set_ps_display(activitymsg);
 
 		/* Track source of data in assorted state variables */
 		readSource = source;

src/backend/bootstrap/bootstrap.c

@@ -342,7 +342,7 @@ AuxiliaryProcessMain(int argc, char *argv[])
 				statmsg = "??? process";
 				break;
 		}
-		init_ps_display(statmsg, "", "", "");
+		init_ps_display(statmsg);
 	}
 
 	/* Acquire configuration parameters, unless inherited from postmaster */

src/backend/commands/async.c

@@ -2225,7 +2225,7 @@ ProcessIncomingNotify(void)
 	if (Trace_notify)
 		elog(DEBUG1, "ProcessIncomingNotify");
 
-	set_ps_display("notify interrupt", false);
+	set_ps_display("notify interrupt");
 
 	/*
 	 * We must run asyncQueueReadAllNotifications inside a transaction, else
@@ -2242,7 +2242,7 @@ ProcessIncomingNotify(void)
 	 */
 	pq_flush();
 
-	set_ps_display("idle", false);
+	set_ps_display("idle");
 
 	if (Trace_notify)
 		elog(DEBUG1, "ProcessIncomingNotify: done");

src/backend/postmaster/autovacuum.c

@@ -434,7 +434,7 @@ AutoVacLauncherMain(int argc, char *argv[])
 	am_autovacuum_launcher = true;
 
 	/* Identify myself via ps */
-	init_ps_display(pgstat_get_backend_desc(B_AUTOVAC_LAUNCHER), "", "", "");
+	init_ps_display(pgstat_get_backend_desc(B_AUTOVAC_LAUNCHER));
 
 	ereport(DEBUG1,
 			(errmsg("autovacuum launcher started")));
@@ -1507,7 +1507,7 @@ AutoVacWorkerMain(int argc, char *argv[])
 	am_autovacuum_worker = true;
 
 	/* Identify myself via ps */
-	init_ps_display(pgstat_get_backend_desc(B_AUTOVAC_WORKER), "", "", "");
+	init_ps_display(pgstat_get_backend_desc(B_AUTOVAC_WORKER));
 
 	SetProcessingMode(InitProcessing);
 
@@ -1680,7 +1680,7 @@ AutoVacWorkerMain(int argc, char *argv[])
 		 */
 		InitPostgres(NULL, dbid, NULL, InvalidOid, dbname, false);
 		SetProcessingMode(NormalProcessing);
-		set_ps_display(dbname, false);
+		set_ps_display(dbname);
 		ereport(DEBUG1,
 				(errmsg("autovacuum: processing database \"%s\"", dbname)));
 

src/backend/postmaster/bgworker.c

@@ -689,7 +689,7 @@ StartBackgroundWorker(void)
 	IsBackgroundWorker = true;
 
 	/* Identify myself via ps */
-	init_ps_display(worker->bgw_name, "", "", "");
+	init_ps_display(worker->bgw_name);
 
 	/*
 	 * If we're not supposed to have shared memory access, then detach from

src/backend/postmaster/pgarch.c

@@ -241,7 +241,7 @@ PgArchiverMain(int argc, char *argv[])
 	/*
 	 * Identify myself via ps
 	 */
-	init_ps_display("archiver", "", "", "");
+	init_ps_display("archiver");
 
 	pgarch_MainLoop();
 
@@ -584,7 +584,7 @@ pgarch_archiveXlog(char *xlog)
 
 	/* Report archive activity in PS display */
 	snprintf(activitymsg, sizeof(activitymsg), "archiving %s", xlog);
-	set_ps_display(activitymsg, false);
+	set_ps_display(activitymsg);
 
 	rc = system(xlogarchcmd);
 	if (rc != 0)
@@ -634,14 +634,14 @@ pgarch_archiveXlog(char *xlog)
 		}
 
 		snprintf(activitymsg, sizeof(activitymsg), "failed on %s", xlog);
-		set_ps_display(activitymsg, false);
+		set_ps_display(activitymsg);
 
 		return false;
 	}
 	elog(DEBUG1, "archived write-ahead log file \"%s\"", xlog);
 
 	snprintf(activitymsg, sizeof(activitymsg), "last was %s", xlog);
-	set_ps_display(activitymsg, false);
+	set_ps_display(activitymsg);
 
 	return true;
 }

src/backend/postmaster/pgstat.c

@@ -4450,7 +4450,7 @@ PgstatCollectorMain(int argc, char *argv[])
 	/*
 	 * Identify myself via ps
 	 */
-	init_ps_display("stats collector", "", "", "");
+	init_ps_display("stats collector");
 
 	/*
 	 * Read in existing stats files or initialize the stats to zero.

src/backend/postmaster/postmaster.c

@@ -4282,7 +4282,7 @@ BackendInitialize(Port *port)
 	int			ret;
 	char		remote_host[NI_MAXHOST];
 	char		remote_port[NI_MAXSERV];
-	char		remote_ps_data[NI_MAXHOST];
+	StringInfoData ps_data;
 
 	/* Save port etc. for ps status */
 	MyProcPort = port;
@@ -4346,10 +4346,6 @@ BackendInitialize(Port *port)
 		ereport(WARNING,
 				(errmsg_internal("pg_getnameinfo_all() failed: %s",
 								 gai_strerror(ret))));
-	if (remote_port[0] == '\0')
-		snprintf(remote_ps_data, sizeof(remote_ps_data), "%s", remote_host);
-	else
-		snprintf(remote_ps_data, sizeof(remote_ps_data), "%s(%s)", remote_host, remote_port);
 
 	/*
 	 * Save remote_host and remote_port in port structure (after this, they
@@ -4423,21 +4419,21 @@ BackendInitialize(Port *port)
 	/*
 	 * Now that we have the user and database name, we can set the process
 	 * title for ps.  It's good to do this as early as possible in startup.
-	 *
-	 * For a walsender, the ps display is set in the following form:
-	 *
-	 * postgres: walsender <user> <host> <activity>
-	 *
-	 * To achieve that, we pass "walsender" as username and username as dbname
-	 * to init_ps_display(). XXX: should add a new variant of
-	 * init_ps_display() to avoid abusing the parameters like this.
 	 */
+	initStringInfo(&ps_data);
 	if (am_walsender)
-		init_ps_display(pgstat_get_backend_desc(B_WAL_SENDER), port->user_name, remote_ps_data,
-						update_process_title ? "authentication" : "");
-	else
-		init_ps_display(port->user_name, port->database_name, remote_ps_data,
-						update_process_title ? "authentication" : "");
+		appendStringInfo(&ps_data, "%s ", pgstat_get_backend_desc(B_WAL_SENDER));
+	appendStringInfo(&ps_data, "%s ", port->user_name);
+	if (!am_walsender)
+		appendStringInfo(&ps_data, "%s ", port->database_name);
+	appendStringInfo(&ps_data, "%s", port->remote_host);
+	if (port->remote_port[0] != '\0')
+		appendStringInfo(&ps_data, "(%s)", port->remote_port);
+
+	init_ps_display(ps_data.data);
+	pfree(ps_data.data);
+
+	set_ps_display("initializing");
 
 	/*
 	 * Disable the timeout, and prevent SIGTERM/SIGQUIT again.

src/backend/postmaster/syslogger.c

@@ -179,7 +179,7 @@ SysLoggerMain(int argc, char *argv[])
 
 	am_syslogger = true;
 
-	init_ps_display("logger", "", "", "");
+	init_ps_display("logger");
 
 	/*
 	 * If we restarted, our stderr is already redirected into our own input

src/backend/replication/basebackup.c

@@ -828,7 +828,7 @@ SendBaseBackup(BaseBackupCmd *cmd)
 
 		snprintf(activitymsg, sizeof(activitymsg), "sending backup \"%s\"",
 				 opt.label);
-		set_ps_display(activitymsg, false);
+		set_ps_display(activitymsg);
 	}
 
 	perform_base_backup(&opt);

src/backend/replication/syncrep.c

@@ -209,7 +209,7 @@ SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
 		memcpy(new_status, old_status, len);
 		sprintf(new_status + len, " waiting for %X/%X",
 				(uint32) (lsn >> 32), (uint32) lsn);
-		set_ps_display(new_status, false);
+		set_ps_display(new_status);
 		new_status[len] = '\0'; /* truncate off " waiting ..." */
 	}
 
@@ -311,7 +311,7 @@ SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
 	if (new_status)
 	{
 		/* Reset ps display */
-		set_ps_display(new_status, false);
+		set_ps_display(new_status);
 		pfree(new_status);
 	}
 }

src/backend/replication/walreceiver.c

@@ -666,8 +666,7 @@ WalRcvWaitForStartPosition(XLogRecPtr *startpoint, TimeLineID *startpointTLI)
 	walrcv->receiveStartTLI = 0;
 	SpinLockRelease(&walrcv->mutex);
 
-	if (update_process_title)
-		set_ps_display("idle", false);
+	set_ps_display("idle");
 
 	/*
 	 * nudge startup process to notice that we've stopped streaming and are
@@ -715,7 +714,7 @@ WalRcvWaitForStartPosition(XLogRecPtr *startpoint, TimeLineID *startpointTLI)
 		snprintf(activitymsg, sizeof(activitymsg), "restarting at %X/%X",
 				 (uint32) (*startpoint >> 32),
 				 (uint32) *startpoint);
-		set_ps_display(activitymsg, false);
+		set_ps_display(activitymsg);
 	}
 }
 
@@ -1028,7 +1027,7 @@ XLogWalRcvFlush(bool dying)
 			snprintf(activitymsg, sizeof(activitymsg), "streaming %X/%X",
 					 (uint32) (LogstreamResult.Write >> 32),
 					 (uint32) LogstreamResult.Write);
-			set_ps_display(activitymsg, false);
+			set_ps_display(activitymsg);
 		}
 
 		/* Also let the master know that we made some progress */

src/backend/replication/walsender.c

@@ -2769,7 +2769,7 @@ retry:
 
 		snprintf(activitymsg, sizeof(activitymsg), "streaming %X/%X",
 				 (uint32) (sentPtr >> 32), (uint32) sentPtr);
-		set_ps_display(activitymsg, false);
+		set_ps_display(activitymsg);
 	}
 }
 

src/backend/storage/ipc/standby.c

@@ -259,7 +259,7 @@ ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist,
 				new_status = (char *) palloc(len + 8 + 1);
 				memcpy(new_status, old_status, len);
 				strcpy(new_status + len, " waiting");
-				set_ps_display(new_status, false);
+				set_ps_display(new_status);
 				new_status[len] = '\0'; /* truncate off " waiting" */
 			}
 
@@ -290,7 +290,7 @@ ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist,
 	/* Reset ps display if we changed it */
 	if (new_status)
 	{
-		set_ps_display(new_status, false);
+		set_ps_display(new_status);
 		pfree(new_status);
 	}
 }

src/backend/storage/lmgr/lock.c

@@ -1737,7 +1737,7 @@ WaitOnLock(LOCALLOCK *locallock, ResourceOwner owner)
 		new_status = (char *) palloc(len + 8 + 1);
 		memcpy(new_status, old_status, len);
 		strcpy(new_status + len, " waiting");
-		set_ps_display(new_status, false);
+		set_ps_display(new_status);
 		new_status[len] = '\0'; /* truncate off " waiting" */
 	}
 
@@ -1789,7 +1789,7 @@ WaitOnLock(LOCALLOCK *locallock, ResourceOwner owner)
 		/* Report change to non-waiting status */
 		if (update_process_title)
 		{
-			set_ps_display(new_status, false);
+			set_ps_display(new_status);
 			pfree(new_status);
 		}
 
@@ -1803,7 +1803,7 @@ WaitOnLock(LOCALLOCK *locallock, ResourceOwner owner)
 	/* Report change to non-waiting status */
 	if (update_process_title)
 	{
-		set_ps_display(new_status, false);
+		set_ps_display(new_status);
 		pfree(new_status);
 	}
 

src/backend/tcop/postgres.c

@@ -1081,7 +1081,7 @@ exec_simple_query(const char *query_string)
 		 */
 		commandTag = CreateCommandTag(parsetree->stmt);
 
-		set_ps_display(GetCommandTagName(commandTag), false);
+		set_ps_display(GetCommandTagName(commandTag));
 
 		BeginCommand(commandTag, dest);
 
@@ -1365,7 +1365,7 @@ exec_parse_message(const char *query_string,	/* string to execute */
 
 	pgstat_report_activity(STATE_RUNNING, query_string);
 
-	set_ps_display("PARSE", false);
+	set_ps_display("PARSE");
 
 	if (save_log_statement_stats)
 		ResetUsage();
@@ -1656,7 +1656,7 @@ exec_bind_message(StringInfo input_message)
 
 	pgstat_report_activity(STATE_RUNNING, psrc->query_string);
 
-	set_ps_display("BIND", false);
+	set_ps_display("BIND");
 
 	if (save_log_statement_stats)
 		ResetUsage();
@@ -2099,7 +2099,7 @@ exec_execute_message(const char *portal_name, long max_rows)
 
 	pgstat_report_activity(STATE_RUNNING, sourceText);
 
-	set_ps_display(GetCommandTagName(portal->commandTag), false);
+	set_ps_display(GetCommandTagName(portal->commandTag));
 
 	if (save_log_statement_stats)
 		ResetUsage();
@@ -4175,7 +4175,7 @@ PostgresMain(int argc, char *argv[],
 		{
 			if (IsAbortedTransactionBlockState())
 			{
-				set_ps_display("idle in transaction (aborted)", false);
+				set_ps_display("idle in transaction (aborted)");
 				pgstat_report_activity(STATE_IDLEINTRANSACTION_ABORTED, NULL);
 
 				/* Start the idle-in-transaction timer */
@@ -4188,7 +4188,7 @@ PostgresMain(int argc, char *argv[],
 			}
 			else if (IsTransactionOrTransactionBlock())
 			{
-				set_ps_display("idle in transaction", false);
+				set_ps_display("idle in transaction");
 				pgstat_report_activity(STATE_IDLEINTRANSACTION, NULL);
 
 				/* Start the idle-in-transaction timer */
@@ -4215,7 +4215,7 @@ PostgresMain(int argc, char *argv[],
 
 				pgstat_report_stat(false);
 
-				set_ps_display("idle", false);
+				set_ps_display("idle");
 				pgstat_report_activity(STATE_IDLE, NULL);
 			}
 
@@ -4365,7 +4365,7 @@ PostgresMain(int argc, char *argv[],
 
 				/* Report query to various monitoring facilities. */
 				pgstat_report_activity(STATE_FASTPATH, NULL);
-				set_ps_display("<FASTPATH>", false);
+				set_ps_display("<FASTPATH>");
 
 				/* start an xact for this function invocation */
 				start_xact_command();

src/backend/utils/init/postinit.c

@@ -236,6 +236,7 @@ PerformAuthentication(Port *port)
 	/*
 	 * Now perform authentication exchange.
 	 */
+	set_ps_display("authentication");
 	ClientAuthentication(port); /* might not return, if failure */
 
 	/*
@@ -303,7 +304,7 @@ PerformAuthentication(Port *port)
 		}
 	}
 
-	set_ps_display("startup", false);
+	set_ps_display("startup");
 
 	ClientAuthInProgress = false;	/* client_min_messages is active now */
 }

src/backend/utils/misc/ps_status.c

@@ -250,12 +250,11 @@ save_ps_display_args(int argc, char **argv)
  * values.  At this point, the original argv[] array may be overwritten.
  */
 void
-init_ps_display(const char *username, const char *dbname,
-				const char *host_info, const char *initial_str)
+init_ps_display(const char *fixed_part)
 {
-	Assert(username);
-	Assert(dbname);
-	Assert(host_info);
+	bool		save_update_process_title;
+
+	Assert(fixed_part);
 
 #ifndef PS_USE_NONE
 	/* no ps display for stand-alone backend */
@@ -309,19 +308,25 @@ init_ps_display(const char *username, const char *dbname,
 	if (*cluster_name == '\0')
 	{
 		snprintf(ps_buffer, ps_buffer_size,
-				 PROGRAM_NAME_PREFIX "%s %s %s ",
-				 username, dbname, host_info);
+				 PROGRAM_NAME_PREFIX "%s ",
+				 fixed_part);
 	}
 	else
 	{
 		snprintf(ps_buffer, ps_buffer_size,
-				 PROGRAM_NAME_PREFIX "%s: %s %s %s ",
-				 cluster_name, username, dbname, host_info);
+				 PROGRAM_NAME_PREFIX "%s: %s ",
+				 cluster_name, fixed_part);
 	}
 
 	ps_buffer_cur_len = ps_buffer_fixed_size = strlen(ps_buffer);
 
-	set_ps_display(initial_str, true);
+	/*
+	 * On the first run, force the update.
+	 */
+	save_update_process_title = update_process_title;
+	update_process_title = true;
+	set_ps_display("");
+	update_process_title = save_update_process_title;
 #endif							/* not PS_USE_NONE */
 }
 
@@ -332,11 +337,11 @@ init_ps_display(const char *username, const char *dbname,
  * indication of what you're currently doing passed in the argument.
  */
 void
-set_ps_display(const char *activity, bool force)
+set_ps_display(const char *activity)
 {
 #ifndef PS_USE_NONE
-	/* update_process_title=off disables updates, unless force = true */
-	if (!force && !update_process_title)
+	/* update_process_title=off disables updates */
+	if (!update_process_title)
 		return;
 
 	/* no ps display for stand-alone backend */

src/include/utils/ps_status.h

@@ -16,10 +16,9 @@ extern bool update_process_title;
 
 extern char **save_ps_display_args(int argc, char **argv);
 
-extern void init_ps_display(const char *username, const char *dbname,
-							const char *host_info, const char *initial_str);
+extern void init_ps_display(const char *fixed_part);
 
-extern void set_ps_display(const char *activity, bool force);
+extern void set_ps_display(const char *activity);
 
 extern const char *get_ps_display(int *displen);