Fix ps display issues

Without this change, ps display of postmaster child processes may get
mangled.  E.g.

postgres: 15432, gpadmin isolation2test [local] con14 cmd52 con14 cm?~??????X???

This change uses the GPDB specific function get_real_act_ps_display()
to get the ps display string before it is modified.

This change also sets Gp_role of FTS daemon process to utility instead
of the default value of dispatch.  That prevents appending "conXXX" to
FTS daemon's ps display.
Co-authored-by: NAsim R P <apraveen@pivotal.io>

src/backend/fts/fts.c

@@ -72,6 +72,7 @@
 /* maximum number of segments */
 #define MAX_NUM_OF_SEGMENTS  32768
 
+bool am_ftsprobe = false;
 bool am_ftshandler = false;
 
 #define GpConfigHistoryRelName    "gp_configuration_history"
@@ -81,7 +82,6 @@ bool am_ftshandler = false;
  * STATIC VARIABLES
  */
 
-static bool am_ftsprobe = false;
 static bool skipFtsProbe = false;
 
 static volatile bool shutdown_requested = false;

src/backend/replication/syncrep.c

@@ -84,9 +84,8 @@ static bool SyncRepQueueIsOrderedByLSN(int mode);
 void
 SyncRepWaitForLSN(XLogRecPtr XactCommitLSN)
 {
-	const char	*old_status;
-	char		*old_status_saved = NULL;
-	int			len=0;
+	char	   *new_status = NULL;
+	const char *old_status;
 	int			mode = SyncRepWaitMode;
 	bool		syncStandbyPresent = false;
 	int			i = 0;
@@ -204,16 +203,19 @@ SyncRepWaitForLSN(XLogRecPtr XactCommitLSN)
 	/* Alter ps display to show waiting for sync rep. */
 	if (update_process_title)
 	{
-		char		activitymsg[35];
+		int			len;
 
-		snprintf(activitymsg, sizeof(activitymsg), " waiting for %X/%X replication",
+		old_status = get_real_act_ps_display(&len);
+		/*
+		 * The 32 represents the bytes in the string " waiting for %X/%X", as
+		 * in upstream.  The 12 represents GPDB specific " replication" suffix.
+		 */
+		new_status = (char *) palloc(len + 32 + 12 + 1);
+		memcpy(new_status, old_status, len);
+		sprintf(new_status + len, " waiting for %X/%X replication",
 				XactCommitLSN.xlogid, XactCommitLSN.xrecoff);
-
-		old_status = get_ps_display(&len);
-		old_status_saved = (char *) palloc(len + 1);
-		Assert (old_status_saved);
-		memcpy(old_status_saved, old_status, len);
-		set_ps_display(activitymsg, false);
+		set_ps_display(new_status, false);
+		new_status[len] = '\0'; /* truncate off " waiting ..." */
 	}
 
 	/* Inform this backend is waiting for replication to pg_stat_activity */
@@ -340,11 +342,11 @@ SyncRepWaitForLSN(XLogRecPtr XactCommitLSN)
 	MyProc->waitLSN.xlogid = 0;
 	MyProc->waitLSN.xrecoff = 0;
 
-	if (update_process_title)
+	if (new_status)
 	{
-		Assert(old_status_saved);
-		set_ps_display(old_status_saved, false);
-		pfree(old_status_saved);
+		/* Reset ps display */
+		set_ps_display(new_status, false);
+		pfree(new_status);
 	}
 
 	/* Now inform no more waiting for replication */

src/backend/storage/ipc/standby.c

@@ -218,7 +218,7 @@ ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist,
 				const char *old_status;
 				int			len;
 
-				old_status = get_ps_display(&len);
+				old_status = get_real_act_ps_display(&len);
 				new_status = (char *) palloc(len + 8 + 1);
 				memcpy(new_status, old_status, len);
 				strcpy(new_status + len, " waiting");

src/backend/storage/lmgr/proc.c

@@ -277,11 +277,12 @@ InitProcess(void)
 	int			i;
 
 	/*
-	 * Autovacuum, WAL sender and FTS handler processes are marked as
-	 * GP_ROLE_UTILITY to prevent unwanted GP_ROLE_DISPATCH MyProc settings
+	 * Autovacuum, WAL sender, FTS handler and FTS daemon processes are marked
+	 * as GP_ROLE_UTILITY to prevent unwanted GP_ROLE_DISPATCH MyProc settings
 	 * such as mppSessionId being valid and mppIsWriter set to true.
 	 */
-	if (IsAutoVacuumWorkerProcess() || am_walsender || am_ftshandler)
+	if (IsAutoVacuumWorkerProcess() || am_walsender || am_ftshandler ||
+		am_ftsprobe)
 		Gp_role = GP_ROLE_UTILITY;
 
 	/*

src/backend/utils/resscheduler/resqueue.c

@@ -1022,7 +1022,7 @@ ResWaitOnLock(LOCALLOCK *locallock, ResourceOwner owner, ResPortalIncrement *inc
 	/* Report change to waiting status */
 	if (update_process_title)
 	{
-		old_status = get_ps_display(&len);
+		old_status = get_real_act_ps_display(&len);
 		new_status = (char *) palloc(len + 8 + 1);
 		memcpy(new_status, old_status, len);
 		strcpy(new_status + len, " queuing");

src/include/postmaster/fts.h

@@ -43,6 +43,7 @@ typedef struct FtsResponse
 	bool RequestRetry;
 } FtsResponse;
 
+extern bool am_ftsprobe;
 extern bool am_ftshandler;
 extern bool am_mirror;